Please Help - Volvo Pentax 3.0 low compression

[Nadersblur]

Hello everyone, I'm pretty new to the boating world. I bought a 18.5 foot Chaparral 180 LE from someone who claimed the motor was replaced and only had 50 hours on it. First season ran fine, kind of choppy, it was winterized and next season it didn't want to start, got it on the water a few times until the day it wouldn't start at the boat launch. Couldn't start it to winterize it at the end of the season so I drained all the water out of it and poured coolant through the hoses. That was when I found a piece of the impeller lodged at one of the connectors to the hose. I've replaced the starter and battery to get it going again this year and it won't start. Checked compression on all 4 cylinders and I'm getting 50 to 60 PSI. I tried the wet test and that got me 80 to 90 PSI. I've been told that it seems to be cranking slow, tried starting it with it hooked up to the car and still didn't start. I've got fuel and spark, feeling defeated and invested too much to give up. Can anyone tell me what else I can try or check, what could be the problem? Any advice or feedback would be greatly appreciated. Thank you

 

[Scott Danforth]

what year?

if those numbers are correct, you need to rebuild the motor

slow cranking would show low numbers and in most cases, if the motor isnt spinning about 120-150 RPM with the starter it wont start.

cranking slow comes from bad battery cable connections. clean every connection from the battery to the starter and back. when you think its clean, go back and clean again. use either a wire brush or a scotchbrite pad. by clean, clean and shiny enough your wife would eat off it.

i take it you never fixed the no-start issue from the boat launch?

 

[criscolumbus]

Personally I would investigate getting it started and running a little before jumping into a rebuild. The engine should start and run with compression in the 50s.

Check Battery condition, Starter, Start wire and relay circuits. Like Scott says slow crank speed will show low compression.

 

[kenny nunez]

2Xs on the above posts. I also think that your piston rings are still washed down with gas. Get a new battery. Get it running and warmed up then the compression should come up.

 

[larson260]

Agree with all above posts. I would suggest removing the plugs and sqirting some oil in the chambers, crank over a few times before trying to start again.

 

[Nadersblur]

It's a 1999, battery is a week old, starter I replaced last season. I will go back and clean the terminals all the connections. I have recently found a bad relay with what looked like a burn hole in it. My out drive wasn't going down but it went up, I swapped the relays and sure enough it was that. I've since cleaned the terminals on the relays and they both work again, even with the burn hole.