In 2005 we bought a new Yamaha F200 for our fleet. A little later we bought a pair of F150's. Within a few years we were hit in the F200 with the now famous Yamaha oil seal and exhaust corrosion issues. This turned out to be major issues for 100's (1000's maybe) of owners, whilst Yamaha did their best Ostritch impression when confronted with the growing evidence. It appears that there are now class action legal suits under way in the US regarding this issue.
The F150's though have run well for 900 hours until a wee alarm popped up the other day. It is a low oil pressure warning. The engine runs and sounds fine apart from a miss around 2000rpm which is a 'safe mode' type action that happens when the oil pressure alarm is active. When the alarm isn't active (mostly isn't) the engine runs like new one. Based on what I was seeing and hearing I figured it was a faulty oil pressure sender, but won't know for sure until we put a mechanical oil pressure gauge on it next week.
This weekend I started looking around the web for a parts supplier. We get 80% of our parts off shore now due to the high margins often applied by the NZ dealers (not just Yamaha - actually they aren't as bad as some others in this regard), so did the rounds of the guys we normally use plus googled for any new ones. WELL, googling Yamaha F150 oil pressure quickly became a very scary thing to do. No, I didn't end up at websites involving donkeys, goats and naked bodies. What I did find is that there is a very serious issue with the F150 that if you own one you need to be aware of.
On the F150 there is a 'counterbalancer' unit which helps smooth out your engine. As I understand it, it has plastic gears that eventually tear apart and fill your oil passages with debris. It seems that the most common reported issue is that the screen in front of the oil pump gets clogged, so catch it in time and you can hopefully avoid any damage. The first sign is often a slight whining noise (haven't heard that in ours), and the next sign is the oil pressure alarm, or a destroyed engine. Some independent commentators on this say that this is not a 'will it happen to my engine' problem, but a 'WHEN will it happen to my engine' problem. The bit of reading I did found cases that happened anywhere from 30 hours or use to over 1000 hours, and anywhere in between. Seem to remember there was one case mentioned on a 2010 F150, so not sure what years are affected, but it would appear that the fix might have come a long time after the problem started showing up.
If you are an F150 owner I would love to know if you have had this problem, and if you haven't had it, have your service guys told you to watch out for it? This appears like it might be another 'Ostritch' response, but maybe we just didn't get the letter.
So if you are an F150 owner, google Yamaha F150 oil pressure and have a read. There are even some youtube videos that demonstrate the whining sound you need to listen out for if you are lucky enough to catch it before losing your engine. If you do have a higher hours F150 and like to go wide, have a good think about whether some preventative maintenance might be a good idea.
I am going to do a proper oil pressure test on our engine this week. Then pull the counterbalance units off both of them for inspection. If the oil pressure is low on the bad engine I am pretty sure that we have caught it before there is any real damage, but the fix will be pulling off the powerhead, cleaning the oil pump screen, then doing some fluffing around to clean out the oil passages as best we can, and finally fitting a new counterbalance unit. I can't tell you how much I hate paying these companies for parts to replace things that they designed wrong in the first place. Not only do they let you down with their quality, they then go on to make extra profit from doing it. It is just a morally bankrupt attitude as I see it. Altogether another $1000 or so and a couple of days work which could have been avoided if we had known a bit earlier that the counterbalance units are badly designed. Don't like to think what it might cost of you just drive it in to your local Yamaha shop. If anyone knows I would love to find out.