compression problems

[st72ay bull3t]

i have a 87' force 125 having a hard time starting, was starting fine but now if it does start, sometimes it will bog out and not even get the boat to plain out other times it will do just fine (only if I'm lucky) i did a compression test it was 120#, 120#, 120#, then when i got to #4 it had condensation on the plug and it was only 90#. i think 10% of 120 would be 12#s when i did the test i only took 1 plug out at a time and motor was cold. Would that give me a false reading? Also is there something else i should be looking at as a problem for starting? she has served me well but maybe time to put her to rest and get a new one ??? Thanks for all your help guys.

 

[jerryjerry05]

You need to remove all the plugs to do the test.
But!!! water on the plug could be a sign the head gasket is bad.
Do the test again and post the results.
30# difference is enough to make the motor hard to start/turn over etc.

If the results are the same then remove the head and check the gasket.
Might be a simple fix.
Remember the head bolts have been there for 30years and might be very hard to remove.
​Some heat, WD-40/ PB Blaster and a hammer will help with removal.