05-03-17, 09:22 PM
(05-03-17, 06:59 PM)fazerscotty link Wrote: A quick method to find where the compression is going is to carry out a leak down test.
Cylinder at TDC (you may have to hold the crank with a spanner) then feed approx 80 psi into the cylinder (convert a spark plug to take an air line). If the rings/bores are worn you'll hear the escaping air from the crankcase breather/oil filler, if its an exhaust valve you'll hear it from the exhaust etc.
Years and years ago I had a GS550, which one day refused to start - checked the compression's and they were all around the 100 mark, which is not enough to encourage combustion. A rebore on all pots had the wee beasty running sweet again.
I have an old air compressor so i may have a look at this