Evinrude 25 Lean sneeze

[Hunter12345]

Crankcase leak or seal issue. Since it stops after using it , thermal expansion will seal crankcase.

That makes sense, ive also noticed some feul/ oil in the cowling by the carb, but assumed it was from the carb, that could be from the crankcase seal?

And after i adjust it when i start it it runs fine, just next time i take it out again itll need more adjustment.
also sometimes it runs fine on the muffs no adjustment needed, is that maybe just the difference in backpressure?

 

[racerone]

Nothing wrong with a little extra oil for a hard working 2 stroke.-----You will get more hours out of it.

 

[racerone]

There is an oil return line from bottom of engine to the top.-----Have you check reed valve plate and gaskets?

 

[Hunter12345]

There is an oil return line from bottom of engine to the top.-----Have you check reed valve plate and gaskets?

yes. i just pulled the powerhead and im going to just replace all the gaskets, seals and recirculation lines.

 

[Hunter12345]

That makes sense, ive also noticed some feul/ oil in the cowling by the carb, but assumed it was from the carb, that could be from the crankcase seal?

And after i adjust it when i start it it runs fine, just next time i take it out again itll need more adjustment.
also sometimes it runs fine on the muffs no adjustment needed, is that maybe just the difference in backpressure?

the seal had the spring out of the lip. could have been the issue but im going to re do all the seals to be safe.

 

[Hunter12345]

i now have the crankcase apart. the connecting rods and caps are discolored, are they supposed to be like that or was it overheating or run without oil?

 

[racerone]

Pictures are needed.----You took the crankcase apart to change the seals?----What do piston skirts look like ?

 

[Hunter12345]

Pictures are needed.----You took the crankcase apart to change the seals?----What do piston skirts look like ?

 

[Hunter12345]

Pictures are needed.----You took the crankcase apart to change the seals?----What do piston skirts look like ?

through the intake and exhaust ports it looks like there is some adhesive wear on the skirts.

 

[racerone]

What do you mean by " discolored " on rods?-----I do not see an issue with rods at all.---Explain " adhesive wear "----Never heard the term before.----Scored pistons ?-----That might be the issue.----Remove the pistons and post pictures.

 

[Hunter12345]

What do you mean by " discolored " on rods?-----I do not see an issue with rods at all.---Explain " adhesive wear "----Never heard the term before.----Scored pistons ?-----That might be the issue.----Remove the pistons and post pictures.

alright they just looked discolored compared to yamaha con rods and caps that ive seen.

And yes they look scored to me sorry shouldve described it that way first.

I will get some pictures of the pistons as well.
thanks

 

[Hunter12345]

Pistons

 

[Hunter12345]

What do you mean by " discolored " on rods?-----I do not see an issue with rods at all.---Explain " adhesive wear "----Never heard the term before.----Scored pistons ?-----That might be the issue.----Remove the pistons and post pictures.

i was thinking take the block to a machine shop to bore the cylinders 0.030" oversize and get new oversized pistons.

 

[Hunter12345]

Update: rebuilt the motor w/ new seals and pistons w/ new rings and now it runs like new.

 

[racerone]

Well done.