Triumphrat

fatric · 06-23-2008, 04:57 PM

Hi all,

Was just changing the plugs and thought whilst out check the compression, left side is reading 95psi, right side is reading 100psi, Troble is i'm unable to find what the compression reading should be, mind you i do think it should be a bit better than what i'm getting, difficult to get the dam thing in place correctly. Anyhow anybody now what the correct compression should be, Bike has no internal work done (yet).
Regards
Ric

JimSouba · 06-24-2008, 12:59 AM

Hi fatric-

By the "textbook", theory says the answer is about 135 psi on the compression guage, at sea level. That's taking the stock engine compression ratio of 9.2 multiplied by normal atmospheric pressure of 14.7 psi. Your actual compression readings could be more or less, depending on elevation, how you conduct the testing, and condition of the engine. The cylinders should be within 10% of each other.

Your readings sound pretty low, and I'd wonder if your guage was installed tight, and the throttle wide open with several compression strokes used for each test. The spark plugs should be grounded during this test, and the motor should (technically) be warmed up.

Hope this info is helpful, and best wishes.

fatric · 06-24-2008, 04:13 AM

Thanks for the reply Jim, motor was cold, turned it over several times on each side, only have a hand held type gauge and it was a mungrel to try and seat it so the readings i'm getting and i'm hopeing are incorrect, have it booked into work shop tomorrow so shall ask them to test it, seems to pull quite good though, uses no oil, just getting this blueing of the pipes and more so to the left, going to have the jetting done, shall see what happens from there.

sweatmachine · 06-24-2008, 11:54 PM

if you did it with a cold engine then the numbers are incorrect.