1st evinrude rebuild

[fixmyevinrude]

1994 Evinrude 200 hp 90 degree looper.

1) Engine started knocking and loosing power
2) No compression middle cylinder port side
3) Pulled head and found needle bearings embedded in top of piston and head, also deep score where piston apparently drug needle bearing from port to top of cylinder
4) Am in process of removing powerhead. Should be off in a few days. I am labeling and photographing everything.

Never have rebuilt a motor before but feel confident that I can do it. I am a tool and die maker and am comfortable with close tolerances.

Since I don't have motor apart yet I don"t know if bearings are from crank or wrist pin. I know I will need a new sleeve.

Assuming the crank is OK I would like to replace one piston, put all new rings and bearings in, replace the bad sleeve and have it bored and honed and have the five remaining cylinders honed assuming they measure out OK

Would like any recommendations, tips, critiques on the above problem and plan to fix it.

Can anyone recommend a shop in the St. Louis, MO area to do the machine work?

 

[R.Johnson]

Re: 1st evinrude rebuild

Are you sure you need a new sleeve? You can go .040 over with a Wisco piston. Whatever machine shop, make sure they have exsperiece with 2 stroke engine's. Measure the groove in the sleeve to determine if it will clean up.

 

[emdsapmgr]

Re: 1st evinrude rebuild

If the needle bearings came out, likely your crank is not reuseable. You'll need at least one rod.

 

[fixmyevinrude]

Re: 1st evinrude rebuild

Are you sure you need a new sleeve? You can go .040 over with a Wisco piston. Whatever machine shop, make sure they have exsperiece with 2 stroke engine's. Measure the groove in the sleeve to determine if it will clean up.

Was told I should use Evinrude piston if I am only replacing one because of weight difference between different manufacturers. Also wondering if it was bored oversize would the other 5 pistons need to be bored oversize?

 

[emdsapmgr]

Re: 1st evinrude rebuild

Bombardier only makes oversize pistons .030 over. If the cylincer won't clean up at .030, you will have to go to .040 over. The factory does permit one (or multiple) over size pistons in a standard bore engine with no other changes needed. (like carb rejetting.) All standard and oversize Bombardier pistons weigh the same. I do not know if the Wiseco .040 will also weigh the same. The wisecos may have different expansion rates than factory pistons, so any single piston overbore replacement may need to have larger piston to liner clearances than normal factory specs for proper operation.