Print Page | Close Window

Honda100 ?

Printed From: The Fishing Website
Category: General Forums
Forum Name: The Boat Shed
Forum Description: Discuss all things boating.
URL: http://www.fishing.net.nz/forum/forum_posts.asp?TID=128090
Printed Date: 23 Jul 2018 at 8:38am


Topic: Honda100 ?
Posted By: Papa78
Subject: Honda100 ?
Date Posted: 26 May 2018 at 12:07am
I’m close to pushing the button on a 5.5m alloy boat (rated up to 115) but still contemplating the engine options.  Have always had Yamaha but no longer any convenient & local dealer/service. That leaves Merc & Honda.  The Merc 115 is the default option (but most expensive).  I’m getting a lot of push towards the Honda 100 as sensible alternative (Honda 115 too heavy) -  it’s certainly a lot cheaper but i’m a bit sceptical for the following reasons (any comment/views gratefully received) :
*  Relatively small capacity at 1500cc vs all others (esp the Merc) with electronic trickery to boost HP (@ top of a steep rev curve  -  even compared to the Honda 90 & 80 with same block).
*  Delivering that HP at the prop via 2.33 box so relatively higher revving
*  Twice the number of moving parts (16v vs 8v)
*  Honda guys at the show said it ideally should run on 95 octane  -  points to the highly tweaked nature of the engine ?



Replies:
Posted By: Don18025
Date Posted: 26 May 2018 at 8:17am
I looked at a Honda 100hp for our Taupo launch acouple of years ago.
If I remember correctly it is the 1500cc Honda Jazz engine block, so I was comfortable knowing that - re engine parts and automotive mechanics with tuning experience. I like engines with a larger use pattern than those specifically for marine use.                        The 80hp and 90hp ran okay on 91, but the 100hp needed 96 - 98 which I was not happy with as other family members use the boat and may fill with the wrong gas. 




Posted By: Steps
Date Posted: 26 May 2018 at 8:37am
 Honda guys at the show said it ideally should run on 95 octane  -  points to the highly tweaked nature of the engine ?

IF 95 is what the manual says.. keep in mind the USA rates octance as an ave, unlike most of the rest of the world.. US 95 is closer to our 91.
 Octane is determined by the cylinder pressure (not compression ratio) at point of firing ATDC at optium piston height /timing position. Higher the pressure  higher the octane required

As to weight between engines.. take say a V4  and a V6  (random brand) difference say 25 kg.
 Now apply that in practical terms.. difference being  less than the live bait tank full....
 yep will have a little difference in a say 4m boat.. a 5.5m.. nah.. you will not even notice anything at rest either


Posted By: Bigfishbob
Date Posted: 26 May 2018 at 9:11am
A mate has the Honda 100 on a 5.5 metre Glass boat, Bonito I think. Goes really well and super cheap to run. 

Another mate has just put a Suzuki 115 on a 5.5 Surtees workmate. I can't believe the fuel economy he gets from that thing. The Suzuki is marginally heavier than the Merc, but no where near the Honda.

I put a 115 Merc on my boat last October, and after running 100 hours, couldn't be happier. 

When it comes to choosing between those three brands, buy the cheapest you can find at the time, the. The pricing relativity changes all the time, and you get dealers who will do their own special deals too. Watch out for extra costs like riging kits and change over costs. Mercs normally price their engines with rigging kits, but Honda didn't when I bought mine. The really are much of a muchness when it comes to reliability fuel economy and service costs. These days the only thing that makes a difference to fuel economy is engine displacement. the bigger the cubes the better the economy, counter intuitive I know. But make sure you have a certified service agent local. Nothing worse than having to keep taking your boat out of town for services.


-------------
www.waikatosportfishing.co.nz


Posted By: Gappy
Date Posted: 26 May 2018 at 11:24am
I have the new Suzuki DF100B on my 6m Rib runs on 91 and just amazing fuel economy has an average consumption of 0.42 lpm does 25knots for 12lph at 4000rpm so quiet also



Posted By: Muzzfishing
Date Posted: 26 May 2018 at 8:01pm
As Bob said I too asked at Boat show about the Honda re 95 octane. Last year in the end went for a 115 as that was the Max reccomended for my boat and from what I heard Surtees like HP and my local dealer sold Suzuki and gave me a really good trade in price so sealed the deal. Now I just go fishing used 6lts petrol last trip for 16.9km seems to be accurate according to petrol pumps.

-------------
http://www.legasea.co.nz" rel="nofollow">     A Good Skipper Keeps the water on the outside of the boat.


Posted By: Papa78
Date Posted: 27 May 2018 at 10:01am
Thanks all for your comments.  Along with other conversations I'm veering toward the Merc (for Extreme 545).  Bob, have seen your posts re props etc  -  may PM you with a few queries.


Posted By: Joker
Date Posted: 27 May 2018 at 3:54pm
Originally posted by Papa78 Papa78 wrote:

Thanks all for your comments.  Along with other conversations I'm veering toward the Merc (for Extreme 545).  Bob, have seen your posts re props etc  -  may PM you with a few queries.

I have the Merc 90 version of the same block but with the command thrust bottom leg - basically the bottom of a 150hp and run it on a FC560 c/c and more than happy with the performance of it. Done over 300 hours in 2 years without missing a beat.  


Posted By: Catchelot
Date Posted: 27 May 2018 at 4:22pm
Originally posted by Joker Joker wrote:

Originally posted by Papa78 Papa78 wrote:

Thanks all for your comments.  Along with other conversations I'm veering toward the Merc (for Extreme 545).  Bob, have seen your posts re props etc  -  may PM you with a few queries.

I have the Merc 90 version of the same block but with the command thrust bottom leg - basically the bottom of a 150hp and run it on a FC560 c/c and more than happy with the performance of it. Done over 300 hours in 2 years without missing a beat.  

Joker can you explain why you have done this, what is the advantage?

Longevity of the lower leg/gear box, etc? What does a command thrust leg do?

CheersClap


-------------
"The sea, once it casts its spell, holds one in its net of wonder forever." - Jacques Cousteau


Posted By: pjc
Date Posted: 27 May 2018 at 6:23pm
Originally posted by Steps Steps wrote:

 Honda guys at the show said it ideally should run on 95 octane  -  points to the highly tweaked nature of the engine ?

IF 95 is what the manual says.. keep in mind the USA rates octance as an ave, unlike most of the rest of the world.. US 95 is closer to our 91.
 Octane is determined by the cylinder pressure (not compression ratio) at point of firing ATDC at optium piston height /timing position. Higher the pressure  higher the octane required

As to weight between engines.. take say a V4  and a V6  (random brand) difference say 25 kg.
 Now apply that in practical terms.. difference being  less than the live bait tank full....
 yep will have a little difference in a say 4m boat.. a 5.5m.. nah.. you will not even notice anything at rest either
Usa fuel ratings are lower than you have stated,
http://www.etuners.gr/fuel" rel="nofollow - www.etuners.gr/fuel

If a fuel is 98 RON then it will be 93 PON -> 93 PUMP
If a fuel is 95 RON and 87 MON then it will be 91 PON -> 91 PUMP



-------------
QMS is not WORKING


Posted By: Muzzfishing
Date Posted: 28 May 2018 at 10:20pm
PJ those fuel rating look confusing boat show was in NZ so dont need to worry about American fuel ratings. Im sure they meant 95 fuel as in NZ fuel  they told me the same thing last year when I asked about the motor. Looks like the Honda 100HP needs 95 fuel to get 100hp. I ended up buying a Suzuki 115, I asked about the fuel he said it would be fine on 91 but would like 95 better. 



-------------
http://www.legasea.co.nz" rel="nofollow">     A Good Skipper Keeps the water on the outside of the boat.


Posted By: Steps
Date Posted: 29 May 2018 at 8:30am
As stated above.. I would NEVER take a sales persons word for corect fuel / saettings what ever.. I would/ do cross reference with manufactures  specs.
 And the number times the off the cuff "specs" turn out incorrect is far too common.
 Correct octane is more than important.. its critical beyond  "best performance" or "economy"  it is critical to the long life of the power head.
 I stated the basic reason / relationship between octane , compression and timing above.
 Increase in octane means increase in timing because higher octane flame burns slower across the chamber to max cylinder pressure.. this results  the piston being lower in the cylinder less compression at max explosion point  therefore requires more advance.
 Less compression means less octane required, less advance.
 Therefore higher octane in an engine doesnt produce more power, and definitely the economy drops dramatically
 The issue on the economy drop , besides the hp at a given rpm drops, is higher octane has lower specific gravity.. less energy per volume .. 
Check the manual.. you will also find in the manual the explanation between how the USA rates octane and our ratings and what we should run.

 Outboards/ marine engines tend to have powerheads more loaded than a car engine.. Because they tend to be under/ min powered right thru the rpm range and propped to max efficiency of the manufactures rpm specs.
Because loaded are far more prone to long term damage be it incorrect propping or fuel octane, or mixture AFR , or timing.
 



Posted By: Gappy
Date Posted: 29 May 2018 at 6:20pm
Steps why do you have to boffin out every post.

The Honda needs NZ 95octane to achieve its 100hp rating the Suzuki needs NZ 91 octane for its engines as stated by the manufacturer can't really get much more simple than that can it.


Posted By: Joker
Date Posted: 29 May 2018 at 8:10pm
Originally posted by Catchelot Catchelot wrote:

Originally posted by Joker Joker wrote:

Originally posted by Papa78 Papa78 wrote:

Thanks all for your comments.  Along with other conversations I'm veering toward the Merc (for Extreme 545).  Bob, have seen your posts re props etc  -  may PM you with a few queries.

I have the Merc 90 version of the same block but with the command thrust bottom leg - basically the bottom of a 150hp and run it on a FC560 c/c and more than happy with the performance of it. Done over 300 hours in 2 years without missing a beat.  

Joker can you explain why you have done this, what is the advantage?

Longevity of the lower leg/gear box, etc? What does a command thrust leg do?
 

 
CheersClap
 
I didn't do it myself - its the Merc CT option that is supposed to give more lift due to spinning a larger prop at a lower prop speed and seems to power my boat well.
 


Posted By: Rozboon
Date Posted: 30 May 2018 at 8:47am
I've never been a huge fan of the highest output model of a given block.

For example in the Hondas, the 80, 90, and 100 are all the 1.5L inline 4.

Aside from just revving it a bit more, it would be interesting to know what, beyond an ECU calibration, has been done to get 20 more hp from the 100 over the 80. I always wonder if it just makes for a more highly-strung, slightly less reliable motor.

All of that said, I was recently out on a DNA 535 with the 80 on it, I was very impressed, extremely smooth and quiet, and the best bit was we did probably 40km that day and the fuel gauge barely moved off Full. I would be surprised if we used more than $50 of gas.


Posted By: Papa78
Date Posted: 30 May 2018 at 7:55pm
Managed to get on the water with an Extreme 545 & Honda100. Unfortunately it had 91 in the tank and certainly didn't have a relaxed grip on proceedings  - just 2 POB and once through 25 kts there was a a feeling the small block was working hard. Adequate and competent but still on track for Merc 115  -  possibly with 4 blader to reduce reliance on trim down as no fwd cabin to keep weight down (WOT not a primary objective).  Am going with 2 batteries and may put them in console (as is the norm overseas) - that moves 35-40kg of dead weight off the transom.


Posted By: Papa78
Date Posted: 30 May 2018 at 8:08pm
"I've never been a huge fan of the highest output model of a given block"

I get the logic but take the view the Merc 115 in a similar position is less of an issue -  more a case that the 90 & 100 are relative outliers at 2.1 litre.  A Yamaha guy at the show admitted their 135 is pushing the limits of tweaking their 1.8 litre block!


Posted By: Bigfishbob
Date Posted: 31 May 2018 at 10:05am
Originally posted by Papa78 Papa78 wrote:

"I've never been a huge fan of the highest output model of a given block"

I get the logic but take the view the Merc 115 in a similar position is less of an issue -  more a case that the 90 & 100 are relative outliers at 2.1 litre.  A Yamaha guy at the show admitted their 135 is pushing the limits of tweaking their 1.8 litre block!

Yes too right it all depends on the size of the block. In terms of the Merc and Suzuki both are around 2.1 litres, compared to 1.8 litres for Yamaha. I would argue that the lower displacement engines are working harder than larger ones at the top of the performance range. 


-------------
www.waikatosportfishing.co.nz


Posted By: Muzzfishing
Date Posted: 31 May 2018 at 5:03pm
Papa I think you will be very happy with the performance of the 115 Merc. Plenty of power and good economy.

-------------
http://www.legasea.co.nz" rel="nofollow">     A Good Skipper Keeps the water on the outside of the boat.


Posted By: Gappy
Date Posted: 31 May 2018 at 8:02pm
Papa where are you based?


Posted By: RC1
Date Posted: 01 Jun 2018 at 8:34am
There must be a local Yamaha dealer in your area, where are you based ?


Posted By: Papa78
Date Posted: 01 Jun 2018 at 8:51am
Nelson region - I have very handy Merc & Honda dealers but Yamaha is 60-90 mins away in a real PITA location to take a boat. The Yamaha service is good once you're there but their regional service is not what it used to be since other shops closed down &/or dropped them.  I believe Yamaha NZ are aware of the issue.  You only appreciate the value of a dealer in close proximity when you need some urgent work during peak summer periods and they tell you to get in the queue behind the Merc and Honda customers !


Posted By: Steps
Date Posted: 02 Jun 2018 at 10:16am
Boffin?  well been asked

I've never been a huge fan of the highest output model of a given block.
For example in the Hondas, the 80, 90, and 100 are all the 1.5L inline 4.
Aside from just revving it a bit more, it would be interesting to know what, beyond an ECU calibration, has been done to get 20 more hp from the 100 over the 80. I always wonder if it just makes for a more highly-strung, slightly less reliable motor.
 A engine of a given volume requires a mixture of a given volume..at a very close  AFR (air fuel ratio). and that proportion of the ratio which is fuel has a given amount of  potential energy stored in it.
 This amount of energry can be increase by raming ( turbo/ blower ) more fuel mixture under pressure  in effect increasing the volume of the engine... but this is not the case here.
By changing cam profiles.. how lomng the inlet is open. how long the inlet and exhaust are open at the same time oine can change the amount of fuel mixture in the chamber , and the compression pressure.. then ( see previous  bofin post on octane , cylinder pressure , time of flame across the cylinder timing and metering (carb or injection)
 These variable therefore change the amount of hp/ torque at any given rpms.
 In saying that , I do not understand the justification huge difference in price between hp models outside simple profit taking..

All of that said, I was recently out on a DNA 535 with the 80 on it, I was very impressed, extremely smooth and quiet, and the best bit was we did probably 40km that day and the fuel gauge barely moved off Full. I would be surprised if we used more than $50 of gas.

 You mentioned the gear ratio// rpm range...
Storta right.. In this case I believe all the hp models have the same gearbox ratio ( have not checked this..)
 The final gear ratio is the prop pitch.
A boat of a given gross weight on the water (wild off the cuff guestimate of 535 say 1100kg).. 
with say a yammy 80 hp motor  will have a WoT of around 37 mph @  approx 5500 rpms 2.31:1 pitch 17
 A cruise @ around 4000 rpms of 25 mph requires approx 40 hp
Put a 115 yamm on WoT will be approx 44 mph @ 45 mph and have a 19 pitch prop ( nicely powered for 1100 kg)  2.15:1
@ 4000 rpms will travel  at cruise @ 4000 rpms 30 mph requires approx 52 hp
 If travel at the same cruise as peed as the 80 hp (approx 2200 rpms) will use far less fuel... and will use far less fuel than the 80 hp. a good 10 to 15% less..
 But get well powered, hull performance increases dramatically and is far easier/ comfortable to travel at the higher cruise speeds including in chop..uses more fuel to move the same weight... But far less fuel than to travel at the same higher cruise with the smaller 80hp.

 So yes the 80 hp wil be economical with the smaller 80hp (if travel at a normal cruise for that sized engine)
 but not as economical if have a larger engine.

 Hope that boffin stuff explains your question..confirms your perception  with the science/ number crunching behind it. 

 Anyone got the WoT,  preferably fully loaded speed of the boat and hp on the back real like numbers? Dont need pitch etc.
Then can calculate the gross weight of the boat on the water.

Am going with 2 batteries and may put them in console (as is the norm overseas) - that moves 35-40kg of dead weight off the transom.
A boat that size even powered with a 80 will not make a difference.. a 115 even less.. and if the weight is more than 1100kg guesstimate, hull design has the bow up a little.. put a prop on with a little more rake ( 4 blades tend to generically have more rake..( its the rake not the blades that make the difference in bow height)

 


Posted By: pjc
Date Posted: 02 Jun 2018 at 6:02pm
"steps" are you a qualified outboard mechanic or just a bush mechanic who has done a lot of reading,I know there are 2 reputable members on this thread and I would take their advice.

-------------
QMS is not WORKING


Posted By: puff
Date Posted: 02 Jun 2018 at 6:15pm
I didn’t realise you had to be a new part changer (qualified mechanic), to give an opinion....
If you only want to listen to 2 people, why not just pm them instead....


Posted By: Steps
Date Posted: 02 Jun 2018 at 7:34pm
If you believe anything I have said above is incorrect, that my maths is incorrect
 Then say so and why.
 I have posted my experiance of the last 50 odd yrs before.. 
Posted the why and hows, the sources, of the maths, the application to real life scenarios, and the limitations of my knowledge and hands on application.

 Rather than simply post up innuendos implying  of bush mechanic as a judgement, If my calculations and  real life hands on data basis are incorrect.. say so and the why.

 A truck drivers license doesnt make a good truck driver right..
 A deg in communication and politics doesnt make a good PM right..
 A trades cert doesnt make a good tradesman ...
 








Posted By: pjc
Date Posted: 02 Jun 2018 at 7:50pm
"steps" you are so easy to wind up,couldnt resist.

-------------
QMS is not WORKING


Posted By: JustAnotherSpearo
Date Posted: 02 Jun 2018 at 9:34pm
Some of you guys who criticizes others inputs are part of the reason I can't be bothered putting input in half the time and often just end up reading. The more often do you it the more people you drive must away.. I can't be the only one.. 

And I'm about as far from a mechanic as possible. However I have spent a heck of a lot of hours onboard small boats and driving them in some seriously snotty conditions this summer has been great fun playing with the 7m hardtops coming back in from out wide when its chopped up and blowing 20knots + and that comes down to experience and understanding the local water movements. I know for a fact I can drive the boats im used to considerably better than most. I'm not a boat operator by trade. I know our outboards in and out, and I know what the common faults with them and am yet to have to call the guardian angles for a tow home and have had many oopsies that required some thinking to get home.
It only takes one look at Steps commander to understand that the man looks after his equipment and uses it a lot. You'd have to be a fool to disregard and take the mickey mouse out of years of experience, time is something we all are limited with. Learn lessons from others and apply common sense to what they say to figure out how reliable it is.

Regarding the topic, stuff a 100hp Honda in my eyes. the 95 octane would throw me off just because of the extra 15cents a litre. Weight difference isn't a real matter in the grand scheme of things. Servicing is an issue, but also can be a bit of a scam, lets be real your average joe isn't likely to encounter problems during the warranty period.. 
but it is piece of mind that cons us all into it. 
4 years with Suzuki, faulty trim switches on the outboard from a poor design with the seal through to the little 25hp 4 stroke not having the robot at the factory connect the throttle cable up correctly forcing it to get stuck at 3000 odd rpm on the first outing. Every outboard can have issues, biggest thing that causes problems is the user and operator with a lack of maintenance and care.

Personally Mercs have had a bad run in our family, black anchors as such. Probably just struck a bad one for the 4 hours we got to use it as a loan motor.  Just thinking about the choices, Merc have developed their 90-115hp range considerably in the last 4 years from where they were. (weight wise and what not) Honda no real developments since we purchased in this hp bracket just whipped out the 100hp outboard, still the same block though.. Back to the point. Mercs have spent time developing and advancing their product, could be a bad thing, could be a great thing. Someone has to be the test pig 


Posted By: MacSkipper
Date Posted: 03 Jun 2018 at 7:23am
Originally posted by JustAnotherSpearo JustAnotherSpearo wrote:

Some of you guys who criticizes others inputs are part of the reason I can't be bothered putting input in half the time and often just end up reading. The more often do you it the more people you drive must away.. I can't be the only one.. 

And I'm about as far from a mechanic as possible. However I have spent a heck of a lot of hours onboard small boats and driving them in some seriously snotty conditions this summer has been great fun playing with the 7m hardtops coming back in from out wide when its chopped up and blowing 20knots + and that comes down to experience and understanding the local water movements. I know for a fact I can drive the boats im used to considerably better than most. I'm not a boat operator by trade. I know our outboards in and out, and I know what the common faults with them and am yet to have to call the guardian angles for a tow home and have had many oopsies that required some thinking to get home.
It only takes one look at Steps commander to understand that the man looks after his equipment and uses it a lot. You'd have to be a fool to disregard and take the mickey mouse out of years of experience, time is something we all are limited with. Learn lessons from others and apply common sense to what they say to figure out how reliable it is.

Regarding the topic, stuff a 100hp Honda in my eyes. the 95 octane would throw me off just because of the extra 15cents a litre. Weight difference isn't a real matter in the grand scheme of things. Servicing is an issue, but also can be a bit of a scam, lets be real your average joe isn't likely to encounter problems during the warranty period.. 
but it is piece of mind that cons us all into it. 
4 years with Suzuki, faulty trim switches on the outboard from a poor design with the seal through to the little 25hp 4 stroke not having the robot at the factory connect the throttle cable up correctly forcing it to get stuck at 3000 odd rpm on the first outing. Every outboard can have issues, biggest thing that causes problems is the user and operator with a lack of maintenance and care.

Personally Mercs have had a bad run in our family, black anchors as such. Probably just struck a bad one for the 4 hours we got to use it as a loan motor.  Just thinking about the choices, Merc have developed their 90-115hp range considerably in the last 4 years from where they were. (weight wise and what not) Honda no real developments since we purchased in this hp bracket just whipped out the 100hp outboard, still the same block though.. Back to the point. Mercs have spent time developing and advancing their product, could be a bad thing, could be a great thing. Someone has to be the test pig 
Great post - I value steps contributions - he came out in my boat and suggested a few things that my mechanic hadn't mainly around trailer setup which was really useful.
Re Merc and development - their new products may be great and salesmen will tell you so like everyone else - personally for boats (and aeroplanes!) I prefer to be a few years behind the leading (bleeding) edge and let someone else take a punt and let me know.


-------------
Good fishing trip nothing breaks, great trip catch fish.


Posted By: smudge
Date Posted: 03 Jun 2018 at 8:17am
I agree, this thread isn't here for picking people apart, that can only be counter productive. Back to talking about Honda 100's please.Steps' input is welcomed as is everyone else's opinion.

-------------


Best gurnard fisherman in my street


Posted By: Steps
Date Posted: 03 Jun 2018 at 9:28am
Back to topic

Regarding the topic, stuff a 100hp Honda in my eyes. the 95 octane would throw me off just because of the extra 15cents a litre.
 So setting the record right here.
 I mentioned before about higheer the octane the lower the SG (persesific gravity)  in rather crude terms . there is less energy stored per L but more energy per weight.
 Now keep in mind we purchase our fuel by volume.. not weight.
When one uses the correct octane fuel for the engine design (cam/ cyclinder pressure /timing/ metering etc) the end result is the $ per distance is very no matter what the cost per L is on the pump.

The exception is where fuels have been 'watered down' with alcohol, be it 91/ 95, 98. In this case the SG becomes even lower.. even less power per L. This applies to most cars as well..
 Basically the cheaper alcohol fuels, even correct octane, thu cheaper on the pump the $ per distance is more expensive

I think you will find most outboards recommend not to use (cheaper) alcohol bases fuels.. so check you manuals.

If you read between the lines of the above.. start doing a few sums, I think you will find if we brought our fuel by the weight, not by the volume, we would get far better value for money and far less be ripped off.

The number ppl who over the yrs call in the workshop, in particular elderly and young complain about their 95/ 98 octane engine doesn't perform and goes thru a lot fuel, ask what they put in , and its cheaper low octane...
 They come back a few weeks later  to say a tank lasts a LOT longer  and power up hills etc is exceptional.

Following is a personal opinion on higher octane in outboards.
 higher octane is more volatile, therefore can degrade the octane rating faster over time... If use a couple times a yr, and always have a full tank, may not be a good idea.. If use couple times a month or more not an issue.
 Thu keeping tank low after a trip, fill up on the way to the 'ramp' with fresh gas is best practice be it a regular or occasional use for marine engines, occasional vintage, classic , hot rod type vehicles.




Posted By: jakepitsville
Date Posted: 13 Jun 2018 at 11:32am
I have replaced an older Honda 90 on my Surtees 5.5 with a Suzuki 115.  both four strokes.

The Honda and Suzuki fuel economy are both about the same at the end of a long day - given the Suzuki is a larger displacement its economy is awesome low down but uses more at high RPM

The Honda - being a carb'd version is way louder, I cant believe how quiet the Suzuki is.

Honda had a gull wing on the back - which made a superb difference to performance.  It was propped correctly stainless.

The Suzuki had a standard prop but a permatrim and the boat handles way way better in a sea - rides like a longer boat.

The large Suzuki pushes the boat much better - its not that the Honda was working "to hard" or anything like that its just the bigger Suzuki just does everything a little easier and goes quite faster - 34 knots vs 27 knots  But fuel economy is the same.

I had to strengthen the outboard pod and modify quite a few things to accommodate the larger heavier outboard - as my Surtee's 5.5 is an older model it needed some tweaking to get it right.  Not a huge deal once we worked out what needed to be down.  I did not think the extra 20 or 30kg would be such a big deal but I defiantly noticed a  difference in boat at rest with the flooding keel. 

Mate has Mercs - not the new ones but mid 2008's I think and he has to fix something every other trip - lucky he has twins else he wouldnt get home.  The new mercs do look the goods but.  

If I was re-powering again, I would have no worries running a Honda, a good reliable and cheap to run (a lot quieter and better fuel economy then my carb'd being injected to)

I would definitely recommend more HP though and my vote goes the the SUZUKI 115


Posted By: Steps
Date Posted: 13 Jun 2018 at 6:28pm
The Honda and Suzuki fuel economy are both about the same at the end of a long day - given the Suzuki is a larger displacement its economy is awesome low down but uses more at high RPM

General note here: to compare 2 engines 
1/must be on the same boat loaded the same... can check that one off.Wink
 2/ Both engines need to be installed at correct heights..
3/ At WoT ideally both should reach max rpms , flat water , best trim at the same or close to the same point... ie if 1 brand is say 4500 to 5500  and max rpms is 1/2 way 5000 rpms.. the other engine needs to also be propped (pitch) at similar position between min and max
4/ The prop slip should also be very similar % @ WoT and @ cruise (cupping and diameter)
5/ Both should be Alloy or Stainless, thu a boat under 1000kg fully loaded, the difference is smaller than a larger boat.
5/ Permatrims create a lot of drag..effect extra weight to the boat... A well powered boat will not need a permatrim, a min or under powered a prop with more rake top lever the bow down
 Therefore the Suzi with the permatrim assuming rpms/ install height etc all correct, the permatrim will knock of a few HP.. reduce in effect the engine size.
6/ Any ecomont numbers need to be taken at the same speeds on both engines...The larger engine will cruise faster easier...Ball park 90 to 115hp will give a good 10 to 15% better economy than the 90 hp cruise speed..and will have fa bettwereconomy at faster cruise speeds.

Yes the more hp will mean less "working" less throttle required, less rpms... 
 A quick check to see how well both engines are set up, the weight numbers should be fairly close +/- 50ish kg

34 knots (115hp?)  1443kg
 vs 27 knots (90hp?) 1617 kg
  I would put a loaded 5.5 surtes around the 1100kg mark at a estimate, therefore a well set up engine height install and correct diameter/ cupping  (slip) and so long as both are anywhere in the manufacturer's WoT rpm range.
115 hp should hit around 38 knt  well powered
 And the 90hp 33 knt..a little under powered.

 There is a lot still to be gained on both the engines..

I would definitely recommend more HP though and my vote goes the the SUZUKI 115
 Yep
 Even with engines not well setup that extra hp at the prop still shows a huge difference... performance/ economy everything...





Posted By: Rozboon
Date Posted: 13 Jun 2018 at 9:37pm
Originally posted by Steps Steps wrote:

I've never been a huge fan of the highest output model of a given block.
For example in the Hondas, the 80, 90, and 100 are all the 1.5L inline 4.
Aside from just revving it a bit more, it would be interesting to know what, beyond an ECU calibration, has been done to get 20 more hp from the 100 over the 80. I always wonder if it just makes for a more highly-strung, slightly less reliable motor.
 A engine of a given volume requires a mixture of a given volume..at a very close  AFR (air fuel ratio). and that proportion of the ratio which is fuel has a given amount of  potential energy stored in it.
 This amount of energry can be increase by raming ( turbo/ blower ) more fuel mixture under pressure  in effect increasing the volume of the engine... but this is not the case here.
By changing cam profiles.. how lomng the inlet is open. how long the inlet and exhaust are open at the same time oine can change the amount of fuel mixture in the chamber , and the compression pressure.. then ( see previous  bofin post on octane , cylinder pressure , time of flame across the cylinder timing and metering (carb or injection)
 These variable therefore change the amount of hp/ torque at any given rpms.
 In saying that , I do not understand the justification huge difference in price between hp models outside simple profit taking..

To be honest I suspect 99% of the motor is the same between the different horsepowers. I would wager a shiny penny that the major difference is the tune loaded on the ECU. Run the 80hp a little fatter, don't advance the timing as much; conversely run the 100hp closer to the knock limit. If they have to be run on 95 octane they're probably already a little bit knock-prone.
I can sit there with my car on a dyno and dial up virtually any power level I want by mashing + and - on a laptop, and I bet you with these motors that are running such similar blocks that's just about all they do.

In fact, because I'm a giant nerd, I went and looked up the US market parts on a Honda 75, 90 and 100, the actual important bits that kinda affect how much power you make (pistons, crankshaft, cams, cylinder head, manifold, injectors) the only difference was the 75 uses a different cam and the 90 has a very slightly different part number for the cylinder head (75 and 100 use the same head). Same gearbox too. Read into it what you will but to my mind all the difference in power output is going to be due to the tune loaded onto the ECU, therefore it's hard to escape the appearance that they're all virtually the same motor and the 100 is just being run harder.


Posted By: Grasshoppa
Date Posted: 14 Jun 2018 at 9:17am
Oh come Rozboon, thats just too simple and makes too much senseLOL
Surely it needs a long winded explanation with formulas etc qualifying it haha

I say this tongue in cheek but your closer to the truth than most think
Originally posted by Rozboon Rozboon wrote:

Originally posted by Steps Steps wrote:

I've never been a huge fan of the highest output model of a given block.
For example in the Hondas, the 80, 90, and 100 are all the 1.5L inline 4.
Aside from just revving it a bit more, it would be interesting to know what, beyond an ECU calibration, has been done to get 20 more hp from the 100 over the 80. I always wonder if it just makes for a more highly-strung, slightly less reliable motor.
 A engine of a given volume requires a mixture of a given volume..at a very close  AFR (air fuel ratio). and that proportion of the ratio which is fuel has a given amount of  potential energy stored in it.
 This amount of energry can be increase by raming ( turbo/ blower ) more fuel mixture under pressure  in effect increasing the volume of the engine... but this is not the case here.
By changing cam profiles.. how lomng the inlet is open. how long the inlet and exhaust are open at the same time oine can change the amount of fuel mixture in the chamber , and the compression pressure.. then ( see previous  bofin post on octane , cylinder pressure , time of flame across the cylinder timing and metering (carb or injection)
 These variable therefore change the amount of hp/ torque at any given rpms.
 In saying that , I do not understand the justification huge difference in price between hp models outside simple profit taking..

To be honest I suspect 99% of the motor is the same between the different horsepowers. I would wager a shiny penny that the major difference is the tune loaded on the ECU. Run the 80hp a little fatter, don't advance the timing as much; conversely run the 100hp closer to the knock limit. If they have to be run on 95 octane they're probably already a little bit knock-prone.
I can sit there with my car on a dyno and dial up virtually any power level I want by mashing + and - on a laptop, and I bet you with these motors that are running such similar blocks that's just about all they do.

In fact, because I'm a giant nerd, I went and looked up the US market parts on a Honda 75, 90 and 100, the actual important bits that kinda affect how much power you make (pistons, crankshaft, cams, cylinder head, manifold, injectors) the only difference was the 75 uses a different cam and the 90 has a very slightly different part number for the cylinder head (75 and 100 use the same head). Same gearbox too. Read into it what you will but to my mind all the difference in power output is going to be due to the tune loaded onto the ECU, therefore it's hard to escape the appearance that they're all virtually the same motor and the 100 is just being run harder.


Posted By: Steps
Date Posted: 14 Jun 2018 at 11:06am
yes a little simple, but basically correct.. there is more to timing than most think or understand..
Timing.. an internal combustion engine has best timing wher max explosion is reached between 12 and 18 degs ATDC.. this is not the set timing as there are a few milli secs for the spark and flame to cross the chamber.
 All degs are in crank degs..
 Withing that 12/ 18 deg (6 degs) the premium timing will be within +/- 1.5 deg..at a given rpms and engine load. 
Also makes the old school swing on the distributor (anologe 'ECU tuning') tune by ear is BS.
Also the tendency to advance is sort of a myth.. Manufactures tend to be sightly low on advance.. espec as a chamber carbons compression rises, higher compression requires less advance, there for a used engine that is set to max advance curve will be over advanced.
 Knock, an engine knocks well before any audible knock.. ball park 2 to 3 degs..and load at a given rpms will also influence the point of knock...
Then throw in a feel/ audible  'optical illusion' effect..

As an engine is advanced the engine will sound 'stronger' so much so you will believe you can feel it in the back of the seat...going up to the optimal advance at a given rpm and load, power/ economy increases quick, go over that advance, it drops off slow.. but keeps on sounding stronger even into inaudible knock. 
Most would increase advance over advance, and engine 6 months later would die and bad machining or similar would get the blame
Advance when dialing in starts high...just below inaudible knock, power will increase slightly then drop of very quick within 1.5/2 degs... at a given load and rpms.

99% of my stuff was done on old school dizzy "(analog).. initial/ centrifugal/ vacuum advance..
When modern self powered sensors  (knock, O2/ emap/ vaccuum) came along that can be run on old school non ECU engines with affordable data loggers (eg the Innovate II) around 20 yrs ago. dialing in to establish the tuning parameters of an old school engine become a very new ball park most never got their head around.
Modern ECU is exactly the same doing it electronically, thu I do find the modern 'technician' not having a background in the analog dizzy, often doesnt have the background understanding of or the tiny tolerances of timing... same as the old school pre sensor/ data logger old school guys.

I have highlighted "at a given load and rpms."
 simply pushing (use a dizzy as example) a cent curve up doesnt work.. the whole curve.. springs weight etc need to be changed right thru rpm range and full load... then the vacuum advance curve needs to be modified for the higher advance required at a given rpm and load right thru the rpm range, and asload changes so does engine vacuum so the influence of that vacuum for that engine at a given load also needs to be taken into account in the VA curve.

 swing on a dizzy ,old school tune by ear... nah doesn't work, just slow death to the engine..
 And the same applies to dialing in electronically modern ECU engines.
 The big advantage on modern ECU/ injection..injection control is almost instant direct into the camber, unlike a carb that has delay and narrow effective rpm range, and knock /emap/ O2 sensors give far more almost instant adjustment right thru thru rpm and load range.


Posted By: Tonto2
Date Posted: 14 Jun 2018 at 7:45pm
ffs killmeknow

-------------
slowly going where everyone else has already been


Posted By: Bounty Hunter
Date Posted: 15 Jun 2018 at 7:44pm
Originally posted by Tonto2 Tonto2 wrote:

ffs killmeknow

LOL


-------------
Death - Our community's #1 killer



Print Page | Close Window