1975 75hp evinrude low compression fix

[HaydenOCurren]

I have a 1975 evinrude 75hp that has low compression in one of the cylinders, I don't remember how low, all I know is that it was too low. so what I'm wondering is how difficult it woould be to repair this one cylinder myself? is it possible to do myself? if so any advice or tips would be a godsend. I don't have enough money for a mechanic so my options are repairing this motor myself or trading for a motor that I COULD fix myself. thankyou guys for any help you give me!

 

[DJ]

Re: 1975 75hp evinrude low compression fix

If you are somewhat handy, you can do it. There are very few specialized tools needed.

However, don't even think about it without the original (reprint) shop manual.

 

[levi_tsk]

Re: 1975 75hp evinrude low compression fix

alright so your in for a tear down if your compression is low UNLESS you have carbon build up in your cylinders or stuck rings...does it run good enough to run sea foam through it?
id start by getting a compression tester from harbor frieght (15-20 bux) and a can of seafoam hook it up to the water hose and get it up to operating temp (about five mins running -dont rev it up too high) hook your compression tester up and check all three cylinders then if you have a low one take a gallon of FRESH gas your can of seafoam and 3 ounces of two stroke oil in a gas can mix it all together and run your engine till this is all gone -its gonna smoke so bad youll think your messing it up but keep it running its burning the carbon from the cylinders piston crowns and rings (hence all the smoke)
recheck your compression and let us know what youve got

 

[levi_tsk]

Re: 1975 75hp evinrude low compression fix

on a side note this is called a shock treament and it CAN clean gummed up carbs to an extent but it isnt a fix for a situation where a complete carb teardown is needed