Compression Test on 88 Force 125

[Barracuda]

Hi,<br /><br />I have a 1988C Force 125 OB Motor on a Barracuda ski boat. I did a compression check on it and all four cylinders were between 120 and 125 PSI. I did the test cold (40 degrees) with the throttle open like the book says. Is this adequate compression? The book states 145-160 for that model, but it seemed to run pretty good last year when all cylinders were 125 PSI. The only issue was at idle, where it would sometimes just quit. Otherwise it ran fine. I have not decarbonized it, nor do I think it ever has been. Does anyone know if the compression is satisfactory or is the motor getting tired? Or is the compression effected because the motor is cold? Any advice is appreciated<br /><br />Thanks.<br />Matt Pottenger

 

[G DANE]

Re: Compression Test on 88 Force 125

Hi Baracuda, I think your fine<br /><br />Compression sounds fine, be aware that many meters gives different readings, they are not that accurate. If compression is even and in the range you have, everything seems fine. A decarb would certainly help, Forces especially have a need for decarb. Compression warm should be around 5-10 higher. The iddle problem sound like som sort of fuel delivery problem, check filters, tank connection and perhaps fuel pump. Try to squeeze primer bulp when it appears, if it improves, you got it. Otherwise, its probably time for carbclean, pay attention to small iddle orifices. Good luck.

 

[Barracuda]

Re: Compression Test on 88 Force 125

Hi G Dane,<br /><br />Thanks for the reply! I will certainly try decarbonizing and will look more closely at the fuel system to find out why it quits idling sometimes. Thanks again.<br /><br />Matt

 

[Mufasa]

Re: Compression Test on 88 Force 125

Barracuda,<br /><br /> The '88 Force 125 you have is tired. The piston fit is loose and at slow speed it does not draw in a good fuel charge. The compression readings are not bad at all but that is only half of the equation. It needs to pull fuel through the reeds into the cylinder and when the piston skirt wears away it becomes loose. This gives you the poor idle, stalls in gear, hard to start. Running a good dose of tuner through it to remove carbon will help but it will not fix it. Try to get one more year out of it and then repower. Use the time to locate a new motor.