Hi,I have been having issues with the bike just not feeling like its got the power it should have....It also seemed hard to start, always needs full choke and even after warming a little is easy to stall, unless its been ridden for a while and its red hot...I have checked a few things, Carb Sync, all but one are spot on, cylinder 3 shows a little less reading than the rest, 20 less, so is an issue thereI also took the chance to measure the cylinder compression and get from 1-4 readings of 110, 100, 115, 102, so varied and well off what the service manual states.Will be trying to pop some oil in the cylinders tommorow or Monday see what a re-test shows.Engine has done 47K, and i had to replace the Water Pump and rear wheel bearing when i got it, not well looked after...I also changed all exhaust studs and replaced the cylinder head gasked whilst in there, replaced spark plugs also.Anyone any comments, do these readings seem well out or reasonable for a bike of this mileage/ageAnutz
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.
Tommy posted the compression figures from the 600 , these are the ones from the 1000 Dont know why it came out sideways , bloody camera phones
All the problems described could be caused by incorrect valve timing. As the cylinder head has been off check and check again. That's timing, not valve clearances.
Another one for valve clearences ....re-grinding the valves would help your compression figures aswell....had my X7 rebored a couple of yeasr ago...£50 per cylinder + new oversized pistons and rings , dont think thats your problem though .....tommy , showing your age there buddy ..those old bikes would have been "overhead valve" engines , valves operated by a push rod from the cam located close to the crank , these new fangled motor cycles have the cam on the top and driven by a chain...called "overhead cam" engines.....still important to check valve clearences on the fazers after head removal....