F300 thrust bearing question

[pstephens46]

It was mentioned on another forum that the thrust bearing failure was much more common on multi-engine boats than single. Interesting concept.

Any truth to this?

[boscoe99]

I saw that. It is THT.

Makes not a lick of sense.

[pstephens46]

Sometimes these things are magic!

[panasonic]

What is the premise of this so called problem? Did anyone give a probable explanation?

[pstephens46]

As I understand it, the thrust bearing on the crankshaft fails on some F300 motors. Bad design apparently. The first symptom is the timing belt begins to shred as the crank develops play, up/down. By this point the motor is mostly toast as there are metal particles in the oil. I have read recommendations of cutting the oil filter in half to inspect for metal after the belt starts to fail.

[boscoe99]

What is the premise of this so called problem? Did anyone give a probable explanation?

He read about it on the inner web. It must be true.

They can not report anything on the inner web that is not true. I read it on the inner web so it must be so.

[pstephens46]

He read about it on the inner web. It must be true.

They can not report anything on the inner web that is not true. I read it on the inner web so it must be so.

I asked the question. I didn't claim there was any truth to it.

It would be curious what Rodbolt has to say on the matter in relation to work he has performed on twins versus singles. We couldn't expect Yamaha to give us any data!

I had a Yam Master Tech tell me he mostly sees the "dreaded o-ring failure" on the Showa trim/tilt units on F150s. Versus other models that use the same unit.

I believe Rodbolt also mentioned spring failures on seals on specific models. I may be misquoting him. But the F225 and F250 I think were common versus others.

Some things can't be proven....we don't have the data. Anecdotal eveidence? Conjecture?

Vitamins are supposedly good for you too.....Did we really put a man on the moon? Or was it a conspiracy?

[Sequoiha]

I haven't seen a single F300 thrust bearing failure, but I did do 3 VF250 Sho power heads this year with thrust bearing failure, single engine applications, 2 in one week.

[rodbolt17]

I have seen it both ways.
some on twins some on singles.
stuff happens.
the first run of 4.2's had more issues.