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