Compression Numbers differ on one cylinder

[onebadc10]

Is this compression on #2 something to be concerned about.It is a 1999 90hp two stroke
cyl 1 140psi
cyl 2 130psi
cyl 3 140psi
cyl 4 140psi

 

[Monte1961]

Re: Compression Numbers differ on one cylinder

is that a dry check?

 

[onebadc10]

Re: Compression Numbers differ on one cylinder

Yes and it is a two stroke

 

[Monte1961]

Re: Compression Numbers differ on one cylinder

try spraying a little oil in to the cylinders and see if it make a big difference? as far as the numbers go not bad as far as i am concerned. have seen worse.

 

[levi_tsk]

Re: Compression Numbers differ on one cylinder

sounds pretty good so far inside of 10% difference does it run? if so id get it up to operating temp and test again let us know what you have then ... the rings in that cylinder may be a little stuck if the engines been sitting for very long

 

[onebadc10]

Re: Compression Numbers differ on one cylinder

Runs good.Just have a little idle issue.

 

[boobie]

Re: Compression Numbers differ on one cylinder

OMC says no more than 15 psi difference between cyls. You should be okay. Try a good decarb on it.

 

[levi_tsk]

Re: Compression Numbers differ on one cylinder

try adjusting the idle mixture on the low cylinder.... but first do a shock treatment decarb like boobie said

 

[scooper77515]

Re: Compression Numbers differ on one cylinder

My opinion, if it runs ok, run it. 10 psi isn't usually a big deal. When it drops to 90, start to worry.