Compression Test - Bad News...

[@paulfowell5253]

The bike has stood for many years and that can adversely affect the compression test, as can testing on a cold engine. Also it sounds like it's turning over slower than I would expect. I am familiar with these as I currently own an 87 H model and also had one when new. Don't be too hasty to conclude there's a problem, put a few hundred miles on it first the re-test. Regards, Paul Fowell, UK.

[@Wolfhoundofwolftrap]

I’d agree I also have a Slabby 11 - I also wouldn’t put much in faith in the accuracy of that cheap compression kit either. The fact they’re all close is great and she’s stone cold and valve clearance should’ve been checked first. His engine is fine

[@paulfowell5253]

@@Wolfhoundofwolftrap Hello skoogmen. Yes the figures are so close that I would not be at all worried unless it was very high mileage, which it isn't. Regards, Paul.

[@advbikeguy]

Valve Clearances were set in the previous videos. I have a feeling that it is leaking from the exhaust valves. The big question is: is it easier to service now, rather than after the motorcycle is back together?

[@LusiTron]

As others have said, the readings are uniform across all cylinders, and that's what matters. Many other variables influence the reading, so don't jump to conclusions, and besides, 120 PSI is not too bad...

[@advbikeguy]

Thanks for taking the time to comment. The Manual does say that if the engine is below 125 PSI, then it needs to be looked at. Stay tuned, we find out why...

[@theoriginalmungaman]

Opening the throttle wide open does little with CV carbs as the slides are down. Your compression test is only a little low as you did it cold. Mine only reads 137psi. Your junk china gauge could be the problem! Slightly tight valves will lower the compression too. The factory specs are not accurate.

[@advbikeguy]

I have a second GSXR1100, and cold it reads 165psi with the gauges that I used in the video. They have been confirmed as accurate, using other testing guages.. Personally, I will go with factory spec, but, each to his/her own.

[@uhtred7860]

Hmm, interesting, the bike is so clean it doesnt look like its racked up many Km/Mi. Did you also do a wet test with a table spoon of oil in the bores? it can help pin point if the rings are worn and not sealing. When you got the bike did it have fibreglass "covers" glued to the frame by the carbs? they are supposed to replicate the ones Team Yoshimura used on their 750s in AMA Superbike. My GSX-R1100 with 50,000Km had reading of 180 across all four.

[@advbikeguy]

The cylinders were oiled prior to the test.