1975 90 hp chrysler 907HB low compression on #3 cylinder suggestions

[toddthax]

my friend is trying to get a 1975 90 hp chrysler 907HB running it has 120 lbs. compression on #1 and #2 cylinders and 45 lbs. on #3 we put oil in the cylinder and ran compression and it went up to 90lbs. could this just be the head gasket leaking into the water jacket or rings we are looking for help on this as we both are just learning to work on these old chryslers

 

[Frank Acampora]

Re: 1975 90 hp chrysler 907HB low compression on #3 cylinder suggestions

More than likely it is stuck rings since compression did come up with oil. However, it could be a head gasket, broken ring, or a lightly scored cylinder.

At this point I would recommend removing the head and inspecting the gasket and cylinder. If ithe cylinder looks smooth and the gasket in good condition, then you need to remove the piston to check the ring condition.

Yeah, you can try a decarb treatment first, but I don't think it will help.

 

[toddthax]

Re: 1975 90 hp chrysler 907HB low compression on #3 cylinder suggestions

we removed the head the gasket looked to be leaking around the cylinder in question the cylinder looks to be in very good shape thanks for your responce we will remove the piston and check the rings and post the results

 

[Frank Acampora]

Re: 1975 90 hp chrysler 907HB low compression on #3 cylinder suggestions

Whoa! Whoa! If the head gasket is or appears to be leaking, don't pull the piston before you try a new head gasket. A new on will cost around 25-35 dollars. Why make more work for yourself than is needed?

 

[toddthax]

Re: 1975 90 hp chrysler 907HB low compression on #3 cylinder suggestions

that is what we are going to do we can pick up new gasket monday thanks for the help