compression test, any info please?

[zophill]

Hi all,
iv just done a compression test on my 2000 storm, the results were 120 PSI on both front and rear cylinders with no throttle. Tried again with quarter throttle and went to 150 PSI. In haynes manual its says 167 PSI.
i dont know if this is good/bad or normal! any info would be a great help and to put my mind at rest.

should the throttle be opened at all when doing compression test?
any ideas on how to improve it IF it is low?

Or is it just down to age of the bike?

cheers

[AMCQ46]

I was always told that you should test with Wide open throttle, but I have no proof that this is correct...you also need to be sure the battery is well charged, and the other plug is out..............if you dont do those you will get a low reading from a good engine.

Also as a dignostic......test it "dry", then put some light oil down the bores to test it "wet" and the difference between these 2 readings would tell you how much leakage is getting past the rings.

[MJONESY]

im pretty sure its throttle wide open with a warm engine, when ive done them ive used a car battery on jump leads to give it the extra spin


edit: just found this http://www.search-autoparts.com/searcha ... p?id=16170

[zophill]

thanks, have checked it with throttle wide open with bores dry and wet, the readings where the same either way at 165 ish.

looks as though everything is fine i just didnt use throttle.

thanks all