Evinrude 48 spl starting and idel problem

[stantheman55]

I have a 1991 Evinrude 48 spl on a 20 ft poontoom boat and I have a idle problem boat will run fine once you get it started I have cleaned the carbs and seen no trash but I cleaned them and put back on. I also checked the comp and had 115 psi on the top but only 80 psi on the bottom as I said boat run good mid range and full throttle but it WILL NOT IDLE. and in my opinion it uses way to much fuel for a 48 hp what could be my problem and how do you adjust the IDle any help would be greatly appreciated thanks stan the man

 

[haffiman37]

This is not an 'adjustment issue', but a rebuild issue due to lack of compression in one cylinder. Max allowed difference between cylinders are 10%. If taken in time, you may get away with just re-boring one cylinder, but if keep on running, you will face a total break down and 'throw away' engine.

 

[racerone]

Agreed , adjustments are not going to help this engine.---Cylinder head must be pulled off for inspection.----If you are lucky you may just have a blown head gasket.