Low compression

jimforce125

Recruit
Joined
Jun 9, 2002
Messages
1
I have a 1989 Force 125HP on a Bayliner Trophy. One motor only revs to 4000RMP at full open. I checked the compression...#1-120PSI. 2-130PSI 3-120 PSI 4-100PSI.<br />I did a wet compression (oil in cylnder) #4-went to 130PSI.<br />Question 1) What is the most likely cause Piston rings or Head gasket? or other possibilities?2) Can a back yard mechanics replace rings?<br />3) What would the parts cost from Iboats?<br />4) How many hours would it take a professional to do the work?<br />5) Will it cause more damage if I contnue to use it as is?<br />All help is greatly appreciated.<br />Jim
 

alcan

Commander
Joined
Dec 14, 2001
Messages
2,505
Re: Low compression

Hi Jim<br />From the numbers you posted it does look like something is up. This may or may not be the cause of your RPM loss. When was the last time you ran some de-carb through it? Might give this a shot first,and see if the compression evens up a bit.
 

Bry21317

Chief Petty Officer
Joined
Apr 9, 2002
Messages
552
Re: Low compression

I have an 88 Force 125 HP, and I ran a can of Sea Foam's Deep Creep Decarb through it it made a huge difference. I found out about this Decarb on here, by some of the guys who swear by it.<br /><br />It brought my compression all back up even, and gave me more power. I also put some Boyeson reeds in and a Hustler HU1317AO, aluminum 17 pitch prop on it, and it runs like a champ now. Pushes my 19 foot Bayliner about 40 now.<br /><br />Hope this helps.<br /><br />Bryan Cox
 
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