F40 propane timing

[mblair441]

My F 40 was converted to propane before I got it. Unlike the MF 50 propane it does not have the factory propane build. I just changed to electronic ignition with all new plugs, wires, coil, etc, but dont feel like Im getting it timed correctly. At idle, the spec is 6 degrees btdc. At higher rpm it goes up, but as I idle down it pops. Also power doesnt seem quite right. When running propane on a stock gasoline engine, where should I set the timing? Im using a timing light but its hard to set. Any other recommendations?
Thanks

 

[Dieseltech]

Years ago when I played with some LP engines, MOST had the distributors advance re-curved for LESS total advance, and the STATIC timing was increased BTDC slightly. That's what the IMPCO LP service book I have shows too, along with several LP IT tractor service specs. Make sure the distributor shaft/bushings are in good condition, worn parts make setting the timing next to impossible.

 

[Stan Coryell]

I'd start by checking the distributor. Mine was missing the advance mechanism. What your total advance at 2000 RPMS? I added a link to a post I had up about a gas Z134 with a Delco Distributer. In hindsight, I should have just bought a new distributor from Pertronix (D41-05A, I think).
link