From: "dinah" To: Subject: Re: blue smoke Message-ID: <001801bf0acf$55059340$531281d8@dinah> Roger: try doing a wet an a dry compression test, if for example you have 120 psi dry an you put oil in the cylinder an your compression goes to 170 its safe to say your rings are worn .if you have less than 20 pecent difference its not your rings. Bob ------------ > The compression test cannot diferentiate between a valve or ring problem, > or even a blown head gasket. > > Lafgas > The best way to test the condition of a motor is a blow down test. Take a spark plug and beat the guts out of it. Weld on a pipe and attach an air fitting to it. Screw it in the spark plug hole with the piston on TDC on the firing stroke, bike in gear and hold rear brake. Hook compressed air to the fitting and simply listen. Hissing out the ..... tail pipe = exhaust valve problem carbs = intake valve problem crankcase vent = bad ring or pistons (a small amount of leak is normal)