Yamaha blow ups

[RidgeRunner]

Is it just me or have Yamahas 4-strokes been blowing up a lot lately?

Spotted (Actually Heard it First) another 150 4-stroke at the ramp this weekend, a smoking and a knocking...
Sounded like it spun a rod bearing..
Smoked like a 2-stroke during break-in..

[Destroyer]

Another happy Yamaha owner...........

[RidgeRunner]

Sick part is, the owners are so loyal/brain washed they bought the same model all over. LOL I was a looking into a 90 4-stroke for the flats boat, but IDK now..

[aussie]

All the fishermen down here are all brain washed that Yamaha are the best nearly every boat has one and most wont buy a boat with out one....

[captpete13]

At my marina right now we have a Yamaha F250 and a Z300 blown. Between that and the F200-225 corrosion problems( I did 2 last week) I don't know why people feel like they HAVE to have one. All I can say is I love my Optimax.

[THEFERMANATOR]

Sounds like a more recent problem as for quite awhile the YAMAHAS were always rock solid. Then again YAMAHA has been here recently trying to squeeze more and more out of there outboards to compete weight wise with the DFI 2 strokes. HONDAS are HEAVY pigs compared to the rest, and SUZUKI also has some corrosion issues(has had for years). It's all these issues that I read about is why I stuck with old school 2 strokes. No they weren't as good on fuel, but if it blew I could buy another engine for what dealers get for a service on one.

[spareparts]

I've worked on just about every type of outboard out there. Around here, numbers don't lie, and i'd have to agree. As far as being a good motor, the Yamaha four strokes are hard to beat. I'm a Mercury man at heart, but the Verados just don't do anything for me. Mercs used to renowned for their corrosion resistance, but now i see them crumble and fizzle like all the imports. The proprietary software on the Verados don't lend themselves to being a choice for independents like my self. There is an aftermarket software package available now, I looked around and noticed I have three verados in the 5 dry stacks I work in that aren't under warranty(they go back to the dealer for service). I work on over 100 Yamaha engines every year, the majority of them being four strokes, the majority of the work I do is regular maintenance. I have yet to find a F200/225 with the corroded oil pan issue, but I know they are out there, just not that plentiful around here. The most common thing I've found that blows up yamahas(and any other EFI engine) is a stuck thermostat(open) that allows the engine to run too cool, the computer compensates and runs the engien rich, gas gets by the rings and dilutes the oil to a water like consistancy. Thats what usually knocks the bearings out(that or water ingestion)I've mentioned my friends that have the harbor taxi that sold their F150's that had over 5000 hours on them(theri current engiens have over 4000). They've had issues with the engines(corrosion and lower units), but they are still running on a grady down in Fl. I like the Suzuki engines, but I've seen some severe corrosion on them personally, they have supposedly changed their alloy, we'll see in a couple of years how they hold up. I believe Suzuki has the best fuel system and one of the better lower units. The biggest disappointment with four strokes to me is Honda, they are way too heavy, way too big, too expensive, not that powerful per the rating, corroded horribly, I don't like the conversion, and parts are high.

When it comes down to it, i can't afford any of them, I'll stick to my old 2.4L 200 merc and my 88 special Johnrude. One thing I can say, is all motors fail in severe conditions, it matters if they are worth repairing or just throwing away.

[RidgeRunner]

You are probably right Ferm, just happenstance. I guess as good as they are they still fail sometimes.
Spare, that is some good insight right there thermostat stuck/washing the rings due to over fueling. Would watching the temp gauge be the only way to see that one coming?

[bradford]

Not an expert by any means, but you may be hearing about Yamaha problems due to the huge amount of them out there. These yamahas have good owners and bad owners. Some do maintainence some don't. Some know to shut something off if they hear something wrong, some don't. If I was gonna buy a four stroke it would be a yamaha. A guide friend of mine has just over 3000 hours on one and does just regular maintainence. Granted his engine gets run regularly several times per week which is better than letting something sit up