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Compression question

N

navchapdoc

Member
"Hell to all. Here is the ques

"Hell to all. Here is the question. I have a 1994 90 hp Merc that is getting the carbs rebuilt today. My Mech called and said that he wanted me to know that my compression was 115, 105 and 80 in the bottom cylinder. The motor runs pretty well for its age although, has a shakey idle which is why I am getting the carbs done. The motor is on a 16.6 Carolina Skiff that I almost never go wide open throttle in. Is this a major prolbem? The motor is way more than the boat needs so, power really is not an issue. Should I go into panic mode over this?
Thanks,
John"
 
"what most likely happened is

"what most likely happened is the engine was ran with a dirty lower carb, no gas means no oil. The mech knows he will never get the engine to run right and is telling you this. Fix it now before there is damage that can't be fixed. Or run it as is and hope for the best. The fuel pump works off of the compression cycles, you are short by some. Sad to see an engine go to lack of maintenance so soon
sad.gif
"
 
"When you say "fix it now&

"When you say "fix it now" do you mean the bad cylinder or the carb prolbem? The Mech is rebuilding the carbs. I found out the motor was cold when he did the compression test. In theory, does that mean once it gets to temp it would have better compression?
John"
 
"Fix the bad cyclinder now is

"Fix the bad cyclinder now is the advice ,much cheaper than letting it go bang ."
 
Shops will rebuild carburetors

Shops will rebuild carburetors if you ask them to! That does not fix the problem.This motor needs the exhaust covers taken off to inspect the lower piston.Pay me now or pay me later ( classic stuff here )
 
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