Yamaha outboard with bent crankshaft..

[Tanda]

Hi

I have a new Yamaha 15 HP two cycle outboard that I just broke in. When going through the shallows, I hit something hard enough to instantly stop the motor. There was little (to no) damage to the prop or skag. The engine did start but it ran poorly like it was out of time. Took it into the dealer to have it checked out and it has a twisted drive and crank shaft. The repairs are the price of a new motor.

Is there or should there be some type of safety device to prevent this kind of damage? Besides staying in deeper water....

Some advice would be helpful!!

Andy

[delcecchi]

Isn't that what rubber hub on prop is for? Hard to imagine doing that kind of damage without wrecking the prop.

[Tanda]

That's what I thought.....but Yamaha thinks different...?

[marine_man]

You must have really hit something hard - that stopped the motor cold in it's tracks. The hub will absorb some of the impact - without it you probably would have twisted the splines of the driveshaft off - not much difference in this case, but if it stopped it cold I wouldn't be too surprised. You could give twin city outboard a call and see if they have a parts motor by chance, but I doubt it.

marine_man

[Valv]

I actually snapped a driveshaft in 1/2 once, It was a Chrysler 100hp, I was testing it on hose and shifted from reverse to forward without letting the prop stop. It cost me $ 125 and a lot of work.

Check with TC Outboard or Boat Motor Recyclers, hsolist could be a good place too.

[Surface Tension]

I think I'd get a second opinion while crossing my fingers that the drive shaft isn't twisted. Are the drive shaft and prop shaft out now? They should be unless the dealer put it back together. Otherwise he couldn't say for sure the drive shaft is twisted.

If the drive shaft twisted then theres damage to the drive shaft bearings, at least.

Being a new outboard, finding a good used lower unit will be hard.

Running rough. when you dead stop an engine by hitting something, its the flywheel thats compounding that force.

The key is most likely crushed, throwing the timing off which explains running rough. You'll have to pull the flywheel and replace the key.