Does my engine have one foot in the grave?

[papagorgio2003]

I have a 1993 katana GSX 750F. My cylinder compression reads 95, 140, 110, and 170 in the 4 cylinders respectively. The specs say they need to be between 142-208. The motor has 35,000 miles on and probably never had a valve adjustment or anyone actually look at the motor. As you could have guess by the messed up compression it runs very very rough ad low RPM (anything below 4000), doesn't idle, doesnt burn completely and leaves gas smell, and backfires constantly (with cool flames coming out of my tailpipes). A few machanics said i should probably just throw it away or get a new engine because it would need new everything (pistons, seals around pistons, valves, gaskets...ect). Do you think me engine is dead or can it be fixed with a lot of time (which i got) and some parts? Is it worth it?

p.s. Everything else on the bike works perfectly (brakes, clutch, transmission, wiring).

Kyle

[Kfreak]

Adjust the valves and do the compression test again at engine operating temperature as the manual says to do. give us an update and we can go on from there.

[arsenic]

dude, ANYTHING can be fixed. If you didn't hold the throttle open when you did the compression test, or if it wasn't at operating temp, you didn't do it right

[Slofuze]

Adjust the valves and do the compression test again at engine operating temperature as the manual says to do. give us an update and we can go on from there.

Spending time is better than spending money.

[Newbie2it]

So many people miss the step of holding the throttle WFO on a warm motor to do a compression check properly.

Hey, be glad you asked first rather then throwing out a good motor.

[md86]

Also , the actual values don't matter as much as the difference . I think it's what , no more than a 10% difference if considered acceptable ? Mine was giving me from 95-105 or so a few years ago . Still ran ok .
Also , after reading a bit , I'd ......
Adjust valves , carb synch , fresh plugs , and see if it's happier . THen check plugs after a few miles (or a tank of gas or 2) and see if any are black . If so , let's look into it further (maybe time for a leakdown test at that point) .... If not , don't neglect the poor thing so much in the future !