Another Yamaha 4.3 Story..bad engine coupler

[crotonpond]

I'm the guy with the 4.3 Yamaha that is looking for parts. Everything is in great shape, but the engine coupler is shot. Can I swap a merc 4.3 engine coupler onto this motor? I have not pulled it yet, trying to figure out options.

 

[Scott Danforth]

since you have to pull the motor out anyway.....suggest you pull out everything yamaha and install mercruiser or volvo.

exhaust manifolds and drive parts are getting harder to get.

 

[crotonpond]

Its hardly worth putting the money into the boat as the hull isn't all that great. I was hopeing to get it through the season if possible and buy in the offseason. With the block being the same as a merc 4.3, I thought it might be possible to retrofit a merc coupler on it?

Will a merc 4.3 pulley to prop be a direct swap? ​

 

[Scott Danforth]

best I can say is pull the coupler, then look for a similar Merc or Volvo unit.

 

[Bondo]

With the block being the same as a merc 4.3, I thought it might be possible to retrofit a merc coupler on it?

Ayuh,..... Boltin' the coupler to the flywheel is the easy part,.....

Do the splines match the Yamaha,..??
Will the coupler clear the flywheel cover,..??
Will the depth be right,..??

I've never even looked a a Yamaha set up,....

 

[Tinman2809]

how do you know when your coupler is bad? I have a Yamaha set up now that's a 4.3

 

[Lou C]

Agreed with Bondo, you would have to basically have the drive off and the couplers (Yamaha and Merc) side by side to take measurements off of to see if it would fit. And, couplers fail for a reason, either the engine was never aligned properly or there is a soft transom allowing the alignment to keep changing. I suggest you try to find out why it failed first, if its a soft transom then I can't see putting any $$ or time into that boat unless you are doing a complete re-fit with a supportable drive train.