Engine Just quit

[Speedling]

Yes, someone did use a belt around the coupler - the round block connecting the crankshaft w/pump shaft - it should rotate with plugs out.
Can't find it now, but I do remember someone has done it, and it should work in theory. Thoughts, @Speedling ?

I guess the good engine would be your positive control.

Totally doable but harder to get in there on the 4 strokes than the 2 smokes.
Still say trailer it and pull pump. Takes longer to put on the trailer than ot does to pull the pump.
Look for silicone missing in there while you are in there to see if it has issues you can fix.

 

[swatski]

Totally doable but harder to get in there on the 4 strokes than the 2 smokes.
Still say trailer it and pull pump. Takes longer to put on the trailer than ot does to pull the pump.
Look for silicone missing in there while you are in there to see if it has issues you can fix.

I agree with @Speedling , that is likely the problem - something stuck up in the pump.

 

[Cobra Jet Steering LLC]

to rule out the timing chain when you turn the starter, if the engine turns really fast with no compression, then it's the chain, if it sounds like it always did when you hit the starter you are ok.

 

[swatski]

@RoughRider said "will engage starter but not turn over". It has got to be a stuck-up pump.

 

[txav8r]

[USERGROUP=9]@HELP[/USERGROUP] have a similar issue. Underway the port engine cut down to 2K and then quit. Put into neutral and will engage starter but not turn over. Limped back to dock and then tried the following:
Checked electrical, safety switches, and pulled sparkplug and have spark and smell fuel.
So there is fire and fuel an crank. So I feel like I ran through the checks but still nothing. Anyone got any ideas?

So yes there was spark and not a dirty plug. Replaced at 10 hours and 3 months later at 26 hours.
Will try to isolate further this morning.
Good news is since it's holiday weekend, I won't even try to go about the amateurs this weekend, but still unhappy.
Kids not wakeboarding this morning is less positive, but getting them ready for life.

Wow...I am amazed how less than 1% of boats made have experienced a timing chain issue, and just the rumor of has everyone jumping to this. It is rare and a remote possibility. @RoughRider probable are the other things mentioned but not clarified. I have reread your posts twice now and they just are not clear from what you have said. @swatski is probably correct here but I want you to clarify what you mean by "starter will engage but not turn over." If your starter tries to turn the motor, and it won't turn, how do you know it is trying to turn it? If you are saying you hear the solenoid click in the starter, but the engine does not turn, maybe the starter is not even turning the engine over. It could be a starter component issue too. Right out of the manual about engines that won't start...

WON'T TURN OVER (Nothing happens when you turn the key)
1.Fuse
2.Battery
3.Shift Lever
4.Starter Component
5.Cleanout Hatch

I don't think your situation falls under the following but repeating for completeness...
TURNS OVER BUT WON'T START (starter spins motor but motor won't fire off or run)
1.Kill Switch
2.Fuel
3.Fuel Tank-water or pressure
4.Spark Plugs or Caps
5.Crankcase filled with Water or Fuel
6.Fuel Filter clogged or water filled

If you hear anything that is indicating when you turn the key, that the start signal is going to the starter, but the engine does not turn, your kind of off the chart but the chart still guides you. For instance, it could be a starter component or a jammed impeller keeping the engine from turning, or it could be a battery issue. But based on what you said, the port engine only reduced to 2K rpm and quit, and assuming the starboard engine repeatedly starts, then we can rule out 2.Battery. Based on you saying the starter engages but won't turn over, we can rule out 1.Fuse, 3.Shift Lever, 5.Cleanout Hatch. What gets missed with the cleanout hatch is that it not only prevents the starter from engaging, but it also kills ignition, so the engine won't run and it won't turn, you don't get a starter signal...just nothing at all. So were back to starter component or something jammed in the impeller. I want to say also, @Cobra Jet Steering LLC is as always, dead on...if you had a broken timing chain, the engine would spin just fine trying to start it...but it would spin without load or restriction, because the entire compression section is cut off from the drive train by the broken chain...although you may get some ugly noises too. Based on what you said @RoughRider , it sounds to me like your pump is just jammed, and all you need to do is inspect and remove the offending object. But really, clarity on what you are actually saying is needed to further guide you. We really need to verify that your starter is engaging and that the engine isn't turning. I don't think your weekend is a total loss at this point, you could be on the water just after lunch!

 

[Cobra Jet Steering LLC]

I have found that when people say it won't turn over what they often mean is it does actually turn over " the engine rotates with the starter , but it just won't start. So in effect it cranks but it won't start. You should come out here and see what we have floating in the water after the storm it's nearly impossible to go anywhere without sucking in trash or avoiding pieces of broken docks that were destroyed by the storm tide. I even sucked in a flag that fell off a boat.

 

[Beachbummer]

I interpreted won't turn over as you described... Engine cranks and rotates, but does not start.

This is why I though it wasn't the pump.

I agree if the engine clicks and does not move at all, the pump might be locked up. Hopefully OP is able to resolve.

 

[bronze_10]

In my neck of the woods .. "turn over" is turning the engine over with the key. Crank is when the engine starts! It's different everywhere i suppose. Lol

 

[RoughRider]

Well there was nothing in the pump. Pulled the pump today and nada. What I mean by won't turn over is that it won't crank. The only sound I hear is a soft whirring that tells me it is spinning. It does not sound the same as starboard starter. So I think it may be just that, a bad starter. However that doesn't explain why it just died while underway. Which to me points to something bigger. So I pulled it back tonight and will goto Dealer tomorrow.

I appreciate all the tips, and all yall are great for the responses. I checked each of the things with my friend who was a jet mechanic in Navy, but hope it is something easy and I feel silly when I update this thread tomorrow and not weeks from now when it will be too cold to boat.

 

[Cobra Jet Steering LLC]

That whirring sound may be the result of the timing chain failing, That was how mine sounded have someone look at the driveshaft or the pump impeller as you try to start the engine if they turn, it's the chain.

 

[txav8r]

Jeff, did you mean to say, "if the don't turn, it's the chain"?

 

[Cobra Jet Steering LLC]

No not at all, the crank turns the shaft so if the pump turns while you are trying to start the engine then the starter is good but the sound is the engine turning over really fast due to no compression from all the valves being bent.
I heard that sound and could see water exiting the pump while I was trying to determine why the engine sounded different you could hardly hear it just a high pitched wine from the starter.

 

[blacksapphirez]

for me everytime it is the clean out hatch switch.

 

[ToddW850]

Hoping for the best outcome on this and hoping it's not what we are thinking. Good luck

 

[elcue]

was it the timing chain?

 

[Cambo]

Curious to find out what happened hopefully it was a minor issue

 

[RoughRider]

Finally heard back from dealer today (Mechanic was on vacation last week).
It was the timing chain. Yamaha warranty will cover 100% and new engine being ordered now. But like previously reported, it will come piece by piece and they will have my boat for however long it takes.

At least it is end of season here in KY but ...

 

[Cobra Jet Steering LLC]

Sorry to hear that, but I was pretty sure that was the issue by your description of the symptoms. Still waiting for my engine to get fixed, starting week 7 today.

 

[RoughRider]

So how many people has the timing chain happened to? It sounded like a rarity, but just wondering.

 

[ToddW850]

Well Dadgummit! Sorry to hear that. At least it is toward the end of your season.