I posted about this a couple of times, and finally took the mower to someone with experience. I'd like to know if you agree with their diagnosis.
JS46 walk behind mower with 190cc OHV Briggs engine... Crankshaft bent about four years ago, but been running fine until this season. Started fine at start of season, but became harder and harder to start the last two uses. Hits, but won't catch and start - pfffft pfffft pfffft pfffft pfffft is all I get now. Continuing to try to start it results in backfiring. When it did start, it ran as good as new. Valve backlash OK. Flywheel key OK. Spark plug has only about ten uses on it. Fuel is fresh.
Here the diagnosis. Since it ran fine once it started, the problem is not with the fuel. Since it backfires, spark is fine, but the backfiring indicates that the timing is off, even though the flywheel key is fine. The mechanic believes there is an internal problem with the cam, or the gears that drive the cam, and that this is causing the valve timing to be off. Cost to prove this would be considerable. Cost to fix it would be prohibitive.
Guys, what do you think? Is there any chance this is something simple that he and I are both missing?
JS46 walk behind mower with 190cc OHV Briggs engine... Crankshaft bent about four years ago, but been running fine until this season. Started fine at start of season, but became harder and harder to start the last two uses. Hits, but won't catch and start - pfffft pfffft pfffft pfffft pfffft is all I get now. Continuing to try to start it results in backfiring. When it did start, it ran as good as new. Valve backlash OK. Flywheel key OK. Spark plug has only about ten uses on it. Fuel is fresh.
Here the diagnosis. Since it ran fine once it started, the problem is not with the fuel. Since it backfires, spark is fine, but the backfiring indicates that the timing is off, even though the flywheel key is fine. The mechanic believes there is an internal problem with the cam, or the gears that drive the cam, and that this is causing the valve timing to be off. Cost to prove this would be considerable. Cost to fix it would be prohibitive.
Guys, what do you think? Is there any chance this is something simple that he and I are both missing?
Aucun commentaire:
Enregistrer un commentaire