Worth checking the oil level in case low oil switch is kicking in esp if reving it and the oil is getting pumped out the sump. Close look at wiring to see if anything is fouling the wires etc Sparkplug - is it definitely clean?
Checking the jets on the carb, there might be a separate one for high speed - could be gunked up, that sounds your most likely scenario since it fits in with the problem developing and not there before, if so could be needing a better fuel filter, or there's some situation that's allowing soot to build up?
@@ShaunDobbie what about your fuel shut off valve - temporarily bypass it? You mentioned the backfire issue when switching off, wonder if that's related?
My first port of call would be to get a wideband and EGT sensor installed, as i said on the first vid, running on gas requires quite close air fuel ratio adjustment or you will produce excessive heat and burn the valves, the valves are not being cooled by evaporation of fuel like with petrol, so you cant get away with it as easy. It looks like you have a set amount of fuel flowing from your regulator? as you rev it up and down using the throttle valve that would just cause the mixture to vary, as not much extra fuel will be pulled through the venturi (if you are using one) like it would with a liquid. This looks like knock to me as it decelerates quickly and makes a slapping noise, which would support the AFR being wrong. Check the regulator isn't deteriorating from all the vacuum pulses / backfires, a tiny hole in the diaphragm will affect pressure significantly. The ignition should be easy to test, put a spark plug or otherwise a gap you can watch externally that will still allow the engine to run and watch it though the rev range, take 2 mins to see if this is the issue.
It has an lpg carburettor kit fitted which draws in the correct amount of fuel using a vacuum regulator which delivers gas during the intake stroke. If the engine is off, no fuel flows.
On propane, I take it you have fitted the proper fuel filter? Might need cleaned/renewed, could bypass by temporally removing the fuel filter try it then try the air filter. Carburettor might need serviced, also worth checking the spark plug to see if it is fouled.
@@ShaunDobbie Yes, strange since you had it working before, maybe open up the distributor and clean it or check alignment, is it contact or contactless, might be worth loosening it so you can turn spark timing back and forth just a touch to see if that changes anything
@dav1dbone It has a cdi ignition with a timing adjustment on it, which does nothing. I am going to try and move the pickup coil a few degrees back and forward.
How small of a bottle and what size regulator are you using? Tank size and regulator size are important. It’s possible it’s not vaporizing fast enough or the regulator is freezing up.
It's a 1.5kg per hour regulator on a 10kg tank. In my video where I tested the generator outside the van, I used the same regulator on a 3.9kg tank and got full power.
Worth checking the oil level in case low oil switch is kicking in esp if reving it and the oil is getting pumped out the sump.
Close look at wiring to see if anything is fouling the wires etc
Sparkplug - is it definitely clean?
Checking the jets on the carb, there might be a separate one for high speed - could be gunked up, that sounds your most likely scenario since it fits in with the problem developing and not there before, if so could be needing a better fuel filter, or there's some situation that's allowing soot to build up?
Oil level sensor isn't connected. Spark plug is a brand new ngk iridium which I checked a couple days ago. Plugs don't foul on LPG.
@@ShaunDobbie what about your fuel shut off valve - temporarily bypass it?
You mentioned the backfire issue when switching off, wonder if that's related?
I have tried without the valve and still same issue.
@@ShaunDobbie how have you piped the exhaust out, is there anyway an obstruction has occurred on the bit that protrudes outside?
Don't forget to adjust the valve.clearances, I had similar.problem on a honda GX200 engine 👌
I've had the key on the crank-flywheel fail which allowed the timing to be off a few degrees causing similar a similar problem.
My first port of call would be to get a wideband and EGT sensor installed, as i said on the first vid, running on gas requires quite close air fuel ratio adjustment or you will produce excessive heat and burn the valves, the valves are not being cooled by evaporation of fuel like with petrol, so you cant get away with it as easy. It looks like you have a set amount of fuel flowing from your regulator? as you rev it up and down using the throttle valve that would just cause the mixture to vary, as not much extra fuel will be pulled through the venturi (if you are using one) like it would with a liquid. This looks like knock to me as it decelerates quickly and makes a slapping noise, which would support the AFR being wrong. Check the regulator isn't deteriorating from all the vacuum pulses / backfires, a tiny hole in the diaphragm will affect pressure significantly. The ignition should be easy to test, put a spark plug or otherwise a gap you can watch externally that will still allow the engine to run and watch it though the rev range, take 2 mins to see if this is the issue.
It has an lpg carburettor kit fitted which draws in the correct amount of fuel using a vacuum regulator which delivers gas during the intake stroke. If the engine is off, no fuel flows.
@@ShaunDobbie Is that one of those AliExpress jobbies?
On propane, I take it you have fitted the proper fuel filter?
Might need cleaned/renewed, could bypass by temporally removing the fuel filter try it then try the air filter.
Carburettor might need serviced, also worth checking the spark plug to see if it is fouled.
Spark plug is brand new and it has no fuel filter on it. Beginning to suspect it's an ignition system issue
@@ShaunDobbie Yes, strange since you had it working before, maybe open up the distributor and clean it or check alignment, is it contact or contactless, might be worth loosening it so you can turn spark timing back and forth just a touch to see if that changes anything
@dav1dbone It has a cdi ignition with a timing adjustment on it, which does nothing. I am going to try and move the pickup coil a few degrees back and forward.
How small of a bottle and what size regulator are you using? Tank size and regulator size are important. It’s possible it’s not vaporizing fast enough or the regulator is freezing up.
It's a 1.5kg per hour regulator on a 10kg tank. In my video where I tested the generator outside the van, I used the same regulator on a 3.9kg tank and got full power.
hi is the mixture off eg too rich or too lean