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2021 Yamaha 275SD engine died - thoughts?

I'm with @swatski on this one.

On a more significant note, this incident does demonstrate conclusively the need for a new 'Holy Sh!t' vote option for the Like button. That was my reaction to BLOWN ENGINE...
 
I would agree, it doesn't.
But - a broken shaft, twice, could explain the blown engine.

Basically, a broken main bearing, or broken shaft in this case, would bend the crankshaft and destroy the motor - one example of failed shaft bearings leading to blown 1.8s was posted by @AboveTheBest, and was documented well on this forum.

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I agree. Yamaha may argue against replacing the engine since they wanted their engineers to investigate the first drive shaft issue and they didn't get the chance to.
 
Don’t know yet
 
Fingers crossed. For the first time in my life I bought a significant extended warranty. I’ll be judgemental to see how they govern themselves.
 
The boat is still to the repair place - Yamaha requested that the engine be “torn down” so they can see what is actually wrong. Apparently that is a big job. Yamaha did not sign off on the tear down and said the owner (me) would need to sign off on that. If they agree to fix it the tear down will be covered. If not, then presumably not. This is the first time I am pissed of (not at the repair place, but Yamaha). I would think that Yamaha would want to smooth things over with a buyer of their range-topper with 52 hours on it that got into a dangerous situation because the boat died. The only rationale I can think of to not authorize the tear down would if they thought I tinkered with it (yeah right....). I am looking for someone I can speak with at Yamaha - anyone know how to contact directly?
 
...make sure you mention to Yamaha that 4000 people are watching this thread.... most of them Yamaha JetBoat owners / enthusiasts
 
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Personal advice, time to lawyer up and get ready just in case.
 
@Sonic Blue @adrianp89

Based on these comments from the OP, Yamaha wanted to inspect the boat and he had the shop fix it without Yamaha inspection. He will be lucky if Yamaha warrantees anything and no chance at a lawsuit.

The engines ran fine at the shop. Mystery because they seemed dead. I told the local guy to fix / replace everything. Not waiting for some Yamaha inspectors to come to a far away place that can do warranty work. Maybe I regret it but gotta try my new BBQ.

I did drive the boat as hard as I could a lot of the time. Constantly doing full sprint from a stop to make the kids squeal and a lot of tubing and wakeboarding. It only has 50 hours though. My current theory is as follows: I heard some whirring/squeaking for a long time before it happened (on way back in). I’m guessing some kind of bearings failed and something was grinding. And creating a lot of friction and getting worse. I gunned when I got out of no wake zone and the RPMs wouldn’t rise very much and then the engine died. I’m guessing that’s when it snapped. I was taking the RPMs up when the drive was having trouble turning. Are there some kind of bearings in there somewhere? The whirring was probably when it was failing.

hoping for <2 weeks.
Boat is fixed and back at the marina. Easy peasey. Now trying to submit repair bill and see what happens. Hopefully Yamaha covers if not I understand because Indidnt follow their advice but was not willing to kiss my boat goodbye for an indefinite period of time. But if they don’t it’s a good warning about this model boat right?
 
@Sonic Blue @adrianp89

Based on these comments from the OP, Yamaha wanted to inspect the boat and he had the shop fix it without Yamaha inspection. He will be lucky if Yamaha warrantees anything and no chance at a lawsuit.

Was the shop a Yamaha certified dealer? He should be fine though - if it's Joe Schmos Jet Boat Repairs - prob SOL.
 
Reading your thread and trying to E-diagnose, LOL, IF the snappage of the shaft was on the same side as the blown engine, see below. If it was the opposite side, disregard:

My bet would be the rod/bearing issue inside of the engine caused a slight imbalance condition on the crankshaft, which created a harmonic vibration that transferred throughout the driveline, snapping the shaft (original failure). After that was fixed, and the engine ran again, the crank bearing spun and fried your motor. Harmonics can travel through gears/shafts/etc. Usually breakage occurs at the end of a given drivetrain (where the power terminates for lack of better word). I've seen it in multiple power transmission arenas. Most of the time, the problem starts "upstream", ie engine/etc.
 
I wonder what the rubber coupler looks like? That *should* isolate the engine vibrations from the shaft, and vise versa.
 
I wonder what the rubber coupler looks like? That *should* isolate the engine vibrations from the shaft, and vise versa.
Not really. For example, shot main pump bearing (from water intrusion) will cause catastrophic engine damage. Presumably related to shaft vibration.
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I wonder what the rubber coupler looks like? That *should* isolate the engine vibrations from the shaft, and vise versa.

Under normal conditions, yes. Every engine has a certain level of harmonics; more or less at certain RPMs. Once those harmonics are blown out of design tolerance, all bets are off. The harmonics can either transfer through the rubber or disintegrate it. This is one of the main reasons auto conversions for homebuilt aircraft have such a high failure rate. Many are riddled with gearbox failures; they all use some sort of rubber coupling for dampening.
 
The boat is still to the repair place - Yamaha requested that the engine be “torn down” so they can see what is actually wrong. Apparently that is a big job. Yamaha did not sign off on the tear down and said the owner (me) would need to sign off on that. If they agree to fix it the tear down will be covered. If not, then presumably not. This is the first time I am pissed of (not at the repair place, but Yamaha). I would think that Yamaha would want to smooth things over with a buyer of their range-topper with 52 hours on it that got into a dangerous situation because the boat died. The only rationale I can think of to not authorize the tear down would if they thought I tinkered with it (yeah right....). I am looking for someone I can speak with at Yamaha - anyone know how to contact directly?

Having you sign off on the tear-down doesn’t mean they don’t plan to pay, They’re just covering their ass.. just in case. I’ve seen where companies make the owner sign off on the tear-down when motors blow before, it’s happened to me and I thought I was about to get the shaft, but the company covered everything.
I think they’re making sure they don’t find serious neglect or aftermarket mods.
 
Crossing fingers for something minor like a plugged cooling water intake.
If my local dealer could get my boat back in the water within two weeks i would love them.
Ronnie, where do you take your boat and ski's for service? Tracy Motorsports? I'm looking for something more local. I bought my boat from West Coast Boat Center.
 
I took the boat to Tracy motor sports for warranty work about 8 years ago they were fine but the ski clinic in Antioch has been my go to place for diagnostics and repairs for over a decade. I highly recommend them.
 
Having you sign off on the tear-down doesn’t mean they don’t plan to pay, They’re just covering their ass.. just in case. I’ve seen where companies make the owner sign off on the tear-down when motors blow before, it’s happened to me and I thought I was about to get the shaft, but the company covered everything.
I think they’re making sure they don’t find serious neglect or aftermarket mods.
The shop tore down the motor and it is a mess inside with metal all over the place. Yamaha declined the repair because they think this was caused by debris in the impeller which cracked the drive shaft and destroyed the motor. They said boat not defective so call insurance. Unfortunately the repair shop also said that this was not caused by ingestion of debris and has photos showing clean impeller and clean break of drive shaft. What a mess. I think it needs a new motor. Yamaha won’t talk with me on the phone (they say their techs only talk with repair shops), the repair shop doesn’t know what to do with a freak occurrence like this + Yamaha saying no (they don’t get paid to argue with Yamaha, and the Dealer who sold me the boat (in a different state) says they have no way to influence this and that they call the same 1-800 number that I do. Any advice?

Fortunately I am in a position to handle these repairs myself, but this is going on 2.5 months now and nothing fixed.

Very disappointed in Yamaha - they do not seem interested in what happened here.

I would not buy a Yamaha product again nor a jet boat.
 
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