noisy 7.5 yachtwin

[PatrickPY23]

I just bought a 1983 7.5 yachtwin Rude.
I tried it at all speed in a water barrel, it runs fine at all speed.

But when i turne the flyweel by hand, it makes a weird irregular "clink clonk"
somewhere like around the upper crank bearing. It sounds a little like a bearing with "square balls". I removed the flyweel, and the crankshaft seems to have a little sideplay. Does theses motors have ball bearing or kind of babbit or brass sleeves?

is it a big job to check this?
Any advice would be welcome.

 

[Robj]

Re: noisy 7.5 yachtwin

The top bearing (closest to the flywheel) is needle, as is the middle crank bearing, the bottom is a ball bearing. You have to split the crankcase to access the bearings, which is somewhat of a big job. You might as well rebuild it if you have gone that far. I would check before, because that ball bearing may no longer be available.

Have a great day,

Rob.

 

[F_R]

Re: noisy 7.5 yachtwin

If the bearings are shot, and it sounds like they are with the side play, the crankshaft is shot also. The needle bearings roll directly on the crankshaft, meaning the shaft is the inner race of the bearing. When one goes, it all goes.

Big job? Yes. Expensive job? Absolutely!!!

 

[PatrickPY23]

Re: noisy 7.5 yachtwin

Effectively i seeked the web for replacement bearings, ans it seems they are not available!!!

Anybody who know if there is any compatible part?

 

[F_R]

Re: noisy 7.5 yachtwin

Sure, they are available. In fact you can order the parts directly from Evinrude/BRP http://shop.evinrude.com/

 

[ISLANDS19]

Re: noisy 7.5 yachtwin

Thanks for the link FR. Effectively, bearing was finished and crankshaft surface was worn, but i found a machinist who grinded it, fit a special sleeve (very hard stuff), and regroud it to proper size. Than i just reinstalled it with new bearing from the link you gived me. about 100 bucks for all the job, and i am ready for another thousands of hours! (as i use this motor about 12 hours per year, will not see it dead!) thank's