Twin Timing Query
Posted: Wed Feb 20, 2002 7:20 pm
Hello from across the pond! I dont want to take alot of your time but I have a question perhaps you could answer. I have a 1951 AJS Model 20, (see cover Jan 200), it likes a lot of ignition advance!
I have checked this from every possible way imagineable! I have strobed it w/timing cover off & know Im looking at the correct criteria. It runs very sluggish at the factory setting. Better, advanced about 10-12 degrees. At the last AJS rally, the singles were leaving me in the dust! If I could better describe it, it runs as if the valve timing were late, but I know its "spot on" Do these suffer from low compression ratios? It "hits" very soft, has decent power off idle, then falls on its face. Advancing the timing w/lever helps somewhat, but it will misfire if left too advanced. There is very little slop in the timing chest, at last teardown cams, pistons, valves all in good "Nick". Does any idea "pop" in your head? Am I perhaps expecting too much from its performance?
Even a poor running 350 Matchy out pulled me up the mountains! We cant have that!
Thank you Mike French.
I have checked this from every possible way imagineable! I have strobed it w/timing cover off & know Im looking at the correct criteria. It runs very sluggish at the factory setting. Better, advanced about 10-12 degrees. At the last AJS rally, the singles were leaving me in the dust! If I could better describe it, it runs as if the valve timing were late, but I know its "spot on" Do these suffer from low compression ratios? It "hits" very soft, has decent power off idle, then falls on its face. Advancing the timing w/lever helps somewhat, but it will misfire if left too advanced. There is very little slop in the timing chest, at last teardown cams, pistons, valves all in good "Nick". Does any idea "pop" in your head? Am I perhaps expecting too much from its performance?
Even a poor running 350 Matchy out pulled me up the mountains! We cant have that!
Thank you Mike French.