tdfregeau

I have a 1989 js 550 bought from original owner it's in great condition nothing has ever been apart on it.I've had it for 3 yrs it's been running great.In an effort for a little more power I added a R&R pipe. It's seems slower now(put in on over the winter)than when I put it away.Tried differant route with the hoses(water box bypass) no real change. I was wondering if I should have made other changes along with the pipe?Maybe the rings are just weak,what is a good compression,again engine has never been apart.Thanks in advance for any help

oilinthegas

not sure what the correct compression should be but anything over or close to 120 psi. air leaks could be suspect for power loss. or have you tried putting on the old parts to see if you could get the old power back?

tdfregeau

The thought of putting old exhaust on has crossed my mind, i'm just being kind of lazy.
I will need to get gaskets to do that etc... I will check compression air leaks is someplace I should look,do you know of a way to test those crank seals?

oilinthegas

so..... if you are being kinda lazy.....then .....there is your problem.
crank seals are checked by blocking off all holes and filling the crank with air 15psi only!!!!! use a regulator to do this. use a plate with a valve stem to block off the intake.

nothing will happen till you get off your a@@



ps you dont need gaskets...black rtv will work.

tdfregeau

I'll get off my a@@ soon thanks for the help,that thing is so fun when it works....