I have a Tennant ride on floor sweeper with a 1.6 GM engine. it wont run more than a few seconds, then backfires. Sounded a a worn camshaft or jumped timing belt. did a compression test with all plugs out and open throttle valve...all 180 except for one at 165. I eliminated all external causes by swapping known good parts from another sweeper. The coil, wires, mixture control and the fuel cut-off, all control valves, crank shaft position senser and even the ECM. Ive removed the cover to check timing belt and verified its all good. Even removed the timing gear and balancer to check if they spun..all good. All valves open and close with good travel...lobes all perfect.
looking for a manual..maybe monday.
anyone have any other ideas.....