Engine Troubles

[boudin]

I was between, I would guess, 5500 and 7500 RPM when it quit.

The valves don't open enough to break them at high RPM, but enough to bend them. Like others have said, it's an interference motor, meaning the pistons can come into contact with open valves at top-dead-center, like what happens when you break a timing chain--the cams stop moving but momentum keep the motor running a stroke.

Bent valves don't necessarily mean damaged valve guides or valve seats (hence a full valve job is needed). Often you can just lap in a new valve, adjust the shims and you are good to go.

Dropping a valve means a valve breaks at the stem, or more likely the keepers work themselves loose (maybe they were not set correctly at the factory). This causes the valve to drop into the cylinder and then destroys a lot of stuff in that cylinder, trashing the block. I don't think that happened in your case as you would still be seeing compression on some of the cylinders.

This is what happens to a motor that drops a valve--extreme case at high RPM:
https://jetboaters.net/threads/mr1-carnage.18712/

Not trying to get your hopes up too much! But just trying to be a bit analytical here based on experience.

-Greg

 

[boudin]

Bent valves... however, this is out of a Kawasaki 12F I rebuilt a while ago.

 

[MattFX4]

If it’s the chain, which I’m sure it is, that’s two this week I have heard about. Another guy over on the timing chain thread just snapped one in his 2012 ar190

 

[WilCo]

Timing chain failure confirmed. Dealer is supposed to be writing up the parts/labor required to repair and submitting to corporate as a claim. My assumption is that corporate will cover it, but don't have that confirmed yet. Corporate did say it would be the new parts list that is used.

 

[Sublime195]

Fingers crossed.

 

[Neutron]

Good luck

 

[WilCo]

Covered by goodwill. So thankful!
Part should be available in next few days. Assume the install will take a bit, but maybe can be back on the water after Labor Day (fingers crossed).

Thanks for all your help in the forum! If I had accepted dealers first answer, I would not have a boat anymore as had no desire to replace the engine at a cost higher than I paid for the boat.

 

[Scottintexas]

What another disappointment in Yamaha dealer network,

Please share the name of this dealer who wants to immediately charge you for a new engine at $15-20k and doesn't even want to check the timing chain,

I guess there's enough 1st time /one time buyers they can continue to treat customers like this,

 

[MrMoose]

@WilCo, you might want to consider moving your boat to another dealership to get this work done. PM me if you want to talk offline

 

[Scottintexas]

@WilCo moose used to live in Houston and also had boat issues, definitely start a conversation with him,

 

[WilCo]

@WilCo moose used to live in Houston and also had boat issues, definitely start a conversation with him,

Thanks. Have talked. Good conversation and same dealer!

 

[WilCo]

What another disappointment in Yamaha dealer network,

Please share the name of this dealer who wants to immediately charge you for a new engine at $15-20k and doesn't even want to check the timing chain,

I guess there's enough 1st time /one time buyers they can continue to treat customers like this,

I hesitate to publish a name publicly when this dealer is responsible for installing my new engine at the moment. I boat at lake conroe in Texas primarily though so it is likely pretty obvious what dealer I am using.

 

[WilCo]

new engine is in the boat, but dealer says the valve cover with tensioner is on backorder until October 2 (previously showed was in stock). Disappointed as they were indicating we would be ready to water test this week, but now have an additional (at least) 2 week delay most likely. Looks like it will be a full 2 months without my boat.