84 90 HP cold compression

[durangopprboy]

84 90 HP cold compression

I am going to a guys house to check out a 84 90hp, he said compression was top to bottom<br />92-115-115-101-125-98<br />The motor is off the boat. I am going to take my own tester and retest. any sugestions on a cold motor and does the compression increase or decrease when motor is warm.

 

[andy6374]

Re: 84 90 HP cold compression

Re: 84 90 HP cold compression

The compression reading should be done on a warm engine. You'll be looking for reading with no more then 10% between the highest and lowest compression values.

 

[timmathis]

Re: 84 90 HP cold compression

Re: 84 90 HP cold compression

I have seen them run great with as much as a 15% difference. Mercury says 10-15% is o.k. withen 10% would be better<br /> If you can get it to run I would do a decarb and then see what you have compression wise. Good Luck, Tim

 

[Clams Canino]

Re: 84 90 HP cold compression

Re: 84 90 HP cold compression

Those numbers are marginal. I'd like to see them warm and after a decarb too.