Is my compression good? 86 dt 85

[luisdeleon]

I got 155, 148, 150. Is that good? Is the differences between the three bad?

Thanks,
Luis

 

[merryacht]

Re: Is my compression good? 86 dt 85

From my experience the closer they are to even the better. That being said, yours are fairly strong and fairly close together. Did you take these after warm-up and in a tank/watercuff?
Why are you concerned with the compression? Those are fine. You would need a variation of 15 between them to begin to worry.
Hope that helps, others will correct me if I'm wrong.

 

[luisdeleon]

Re: Is my compression good? 86 dt 85

no not on warmed up just got this motor and am fixing it up for my boat so far everything is good except for carbs and pump wich the rebuilt kits are on the way. the onlything that worried me was compression witch i didn't check when i got it but looks good. just was wondering if that variation between them was good or bad.

thanks

luis

 

[luisdeleon]

Re: Is my compression good? 86 dt 85

wouldn't it get better if the engine is warm? wouldn't the rings expand a bit due to heat? giving it higher compression.

 

[merryacht]

Re: Is my compression good? 86 dt 85

I wouldn't worry about those numbers at all.
On the rebuild, make sure you get some good marine carb cleaner, the foaming kind, that will eat the varnish now. Gum-out etc won't cut it. Also remember to use forced air to blow everything clean and dry. then just rebuild and set to factory specs. Don't forget to clean the low speed jets and the fuel filter.
Shoot me a private message if you need specs, as I have a Suzuki manual, and an 87 dt85.

 

[luisdeleon]

Re: Is my compression good? 86 dt 85

Thank you