1991 120 Johnson looper

[Chris1977]

I have overheated my motor and done some damage to cylinder #3,I want to know if there are sleeves in there or do I have to bore it? Any and all help will be greatly apprieciated.

 

[wilde1j]

Re: 1991 120 Johnson looper

Bore it, unless damage won't allow boring, then re-sleeve (more expensive than boring).

 

[Faztbullet]

Re: 1991 120 Johnson looper

As "wilde1" said you can bore it up to .040 oversize, but usually overheating will damage and scuff all cylinders not just one.

 

[kenmyfam]

Re: 1991 120 Johnson looper

If you have it all apart to bore one cylinder then it would make sense to me to bore them all while it is off.

 

[SparkieBoat]

Re: 1991 120 Johnson looper

yes and over heating can also harden the rings on the other pistons..making them brittle. bore all cylinders the same.