F300 4.2. Thrust bearing failure

[formula29]

I am concerned I may have a thrust bearing on the way out. 1500 hrs on 2nd power head. I can pull the crank up about .060 or about 1/16 ". The motor still runs fine but I can't find any specs for this. Thanks for any help

[boscoe99]

I have never seen or heard of any specifications from Yamaha with respect to the thrust bearing.

What is your Yamaha dealer telling you?

Has he been in contact with Yamaha?

Has the dealer checked the oil system for the presence of metal flakes, shavings, etc.?

[formula29]

Unfortunately I bought the motor used and out of warranty. The first owner had the power head replaced at 1000 hrs under warranty. And he put 1400 on the current one before I bought it. Is it normal to be able to pull up on the flywheel .060 On these motors? I can actually pull up on the flywheel by hand and let go and here a clunk. It just don't seem right. And if it is not normal I want to tear it down before it's ruined if it's not already

[boscoe99]

Have you talked to your dealer and/or Yamaha customer support about getting the motor repaired (if needed) under their goodwill policy?

Unless the motor was registered for commercial use Yamaha US has a pretty generous goodwill policy for pleasure users. This presumes the motor was sold by Yamaha USA and is registered accordingly.

That is a lot of time on a motor by the way, if in fact it is used only for pleasure.

As I said, if there there is a specification for crankshaft play I have never been able to find it. Try and find a dealer that is familiar with the Offshore and SHO series of motors and have them do an inspection to see what they have to say.

It will be major surgery if the thrust bearings need to be replaced. If they are worn out, hopefully there is no collateral damage.

Maybe Rodbolt will have something more to add.

[formula29]

Thank's Boscoe, I bought the motor from a Yamah Pro staff guy he was a fishing guide so I would say it was comercial use, so I don't expect any warranty, I am just trying to find someone that know's if this is a normal condition I have or if it indicates worn thrust bearing as I suspect, If it is worn bearings I don't mind the work of changing them I just hope I caught it in time and the crank and block are ok.

[robert graham]

Rodbolt should have some ideas on this...Probably this evening or early AM tomorrow....the average guy probably won't know about this....

[boscoe99]

A pro staff motor would not normally be considered as commercial usage by Yam US. After all, they are in bed with the guy.

It would cost you nothing to make a call to Yamaha to see what the situation is. Or, give me the complete engine ID and I will see what I can come up with.

[formula29]

I will send the serial to you if you don't mind looking into it, I bought a used motor as is, but I did expect to get more than 50 hrs out of it, funny part is the guy a got it from has an artical on yamahas web site praising this particular engine that has 2,400 trouble free hrs on it, however he fails to mention it is the second power head,

[rodbolt17]

drop a dime dude.
cant hurt and the worst they can say is sorry.
thrust bearing failure on the early 4.2L v6 was rather common.
typically thrust bearing spec is .003-.007" or so. .060 is enough to QUIT running the engine as TOTAL engine failure is imminent.
typically they will run until the cam drive belt gets cut then its a catastrophic failure involing the valves and the pistons.

[formula29]

Thank you Rodbolt, I was looking for conformation of what I pretty much knew from a pro. I actually tried to call yamaha today and was on hold forever before I gave up, I'm not even sure I was calling the right department, I will try again tomorrow, that is sad that they have this design problem for such a high dollar engine, I should have stuck with my old ox66's that I loved!

[rodbolt17]

they say its fixed now but a few had some driveshaft/crankshaft spline issues.

[formula29]

New crankcase

Thank's for the information and support, Yamaha stepped up and provided me with a new short block for free! A guy could not ask for more I dont think,,That kind of good will I never expected, the only bad part is there was a 2013 sho 250 with only 28hrs on a pontoon boat that came in the same shop as mine with complete crankshaft failure, my local shop said they had never heard of this problem befor mine and now two in the same week?

[boscoe99]

Good for you.

Be sure and let the crowd at THT know.

[formula29]

I frequent Tht for help and knoledge and just pure entertainment sometimes. There are a few good guys and a whole bunch of narrow minded idiots. I have a thread on there about this and you would not believe some of the off the wall b.s, it went from me asking how many guys had 4.2's with high hrs without failure, to the evinrude guys to merc guys bashing each other's product, I think I only had 2 or 3 guys that actually owned the 4.2 reply. I think these are by far the best running engine I have ever owned, aside from the thrust bearing deal, I hope I am in the few percent of failures and this is really not going to be a wide spread problem for yamaha. I have posted on tht that yamaha customer service good will'd a new crankcase for me 1 year out of waranty and I am very impressed with that. they did not have to help me at all.

[boscoe99]

I frequent Tht for help and knoledge and just pure entertainment sometimes. There are a few good guys and a whole bunch of narrow minded idiots. I have a thread on there about this and you would not believe some of the off the wall b.s, it went from me asking how many guys had 4.2's with high hrs without failure, to the evinrude guys to merc guys bashing each other's product, I think I only had 2 or 3 guys that actually owned the 4.2 reply. I think these are by far the best running engine I have ever owned, aside from the thrust bearing deal, I hope I am in the few percent of failures and this is really not going to be a wide spread problem for yamaha. I have posted on tht that yamaha customer service good will'd a new crankcase for me 1 year out of waranty and I am very impressed with that. they did not have to help me at all.

I agree with your last sentence wholeheartedly. Unfortunately, all too many think a manufacturer (or the government) owes them everything for life. All too many are just wanting a handout.