Honda Ride on Mower - intermittent problem - misfire?
Discussion
Hi, I know this isn't a car but I thought you piston heads would be able to help.
If you look at this video link
https://www.youtube.com/watch?v=KVzZQRM65OM&fe...
When the throttle is lowered and then put back up to full speed the mower will cough and splutter and sound like that, then it varies but will go back to normal again after between 5 and 15 mins.
It's just come back from a service and has had new carb and new piston as these were causing it to not work at all before. (carbon had something loose inside and piston was worn or broken I'm not sure)
It's just strange how it works perfectly fine then this happens when the throttle is lowered.
Cheers for any help :-)
If you look at this video link
https://www.youtube.com/watch?v=KVzZQRM65OM&fe...
When the throttle is lowered and then put back up to full speed the mower will cough and splutter and sound like that, then it varies but will go back to normal again after between 5 and 15 mins.
It's just come back from a service and has had new carb and new piston as these were causing it to not work at all before. (carbon had something loose inside and piston was worn or broken I'm not sure)
It's just strange how it works perfectly fine then this happens when the throttle is lowered.
Cheers for any help :-)
Some engine details would help! - however the sound I'm hearing is that of a twin cylinder engine only running on one cylinder. That should make it very easy to diagnose even for an ursine of minimal intra-cranial capacity.
When it's misfiring pull off one plug lead. If there's no change that's the faulty cylinder. If the engine stops it's the other cylinder that wasn't firing. It's unlikely to be the carb as that must presumably feed a single manifold splitting to both cylinders and would affect both equally so it's more likely either an ignition fault or a mechanical fault on that cylinder. An ignition fault would usually manifest at high throttle rather than low throttle but can't be ruled out so first check that the spark is strong at both plugs by earthing them in turn against the engine block. If both sparks are good then check the valve clearances then do a compression test.
If compression is low on one pot it hasn't been rebuilt properly.
When it's misfiring pull off one plug lead. If there's no change that's the faulty cylinder. If the engine stops it's the other cylinder that wasn't firing. It's unlikely to be the carb as that must presumably feed a single manifold splitting to both cylinders and would affect both equally so it's more likely either an ignition fault or a mechanical fault on that cylinder. An ignition fault would usually manifest at high throttle rather than low throttle but can't be ruled out so first check that the spark is strong at both plugs by earthing them in turn against the engine block. If both sparks are good then check the valve clearances then do a compression test.
If compression is low on one pot it hasn't been rebuilt properly.
I couldn't film it but when it's misfiring I unplugged one spark lead then the other as you said puma but there was no change...
It's a 2005 Honda HF2315 SB 530cc OHC V-twin roughly the same as this http://www.honda.co.uk/garden/ride-onmowers/HF2315...
I'll contact the guy that serviced it tomorrow.
It's a 2005 Honda HF2315 SB 530cc OHC V-twin roughly the same as this http://www.honda.co.uk/garden/ride-onmowers/HF2315...
I'll contact the guy that serviced it tomorrow.
The poster who suggested you film it was being facetious. He was implying you'd get an electric shock when you pulled a plug lead off. Perhaps if you were foolish enough to do this bare handed he might be right.
Anyhoo - I fail to see how removing each of the two leads in turn doesn't cause any change at all. Either both cylinders are running but misfiring badly and removing either lead would stop one cylinder completely thus making things worse or one cylinder is fine and the other not firing at all in which case removing the good lead would stop the engine completely. Only removing just the bad lead in the second case would cause no change but removing the other lead would have to change things.
The only possible solutions to this logic problem are:
A) You are unable to hear the change in the engine's running and thus feeding us duff information.
B) The engine is not relying on the plugs to run i.e. it is pre-igniting on hot spots in the combustion chambers due to the wrong plug grade or some serious mechanical malady such as incorrect ignition or valve timing causing severe overheating.
In this case I would expect the engine to run on even after switching the ignition off unless there is also a fuel cut off.
Assuming you are not completely deaf or terminally stupid then B seems like a viable explanation. Given it's just been rebuilt it is easily within the bounds of possibility that the cam or ignition system has not been installed correctly. However the engine would have to be well down on power even when not misfiring. Is it?
Anyhoo - I fail to see how removing each of the two leads in turn doesn't cause any change at all. Either both cylinders are running but misfiring badly and removing either lead would stop one cylinder completely thus making things worse or one cylinder is fine and the other not firing at all in which case removing the good lead would stop the engine completely. Only removing just the bad lead in the second case would cause no change but removing the other lead would have to change things.
The only possible solutions to this logic problem are:
A) You are unable to hear the change in the engine's running and thus feeding us duff information.
B) The engine is not relying on the plugs to run i.e. it is pre-igniting on hot spots in the combustion chambers due to the wrong plug grade or some serious mechanical malady such as incorrect ignition or valve timing causing severe overheating.
In this case I would expect the engine to run on even after switching the ignition off unless there is also a fuel cut off.
Assuming you are not completely deaf or terminally stupid then B seems like a viable explanation. Given it's just been rebuilt it is easily within the bounds of possibility that the cam or ignition system has not been installed correctly. However the engine would have to be well down on power even when not misfiring. Is it?
OK you are probably pulling the throttle just far enough to bring the the choke flap into play and gassing the engine up pull more gently and the fault will go away ,I used to look after a number of mower before I retired , the drivers were of mixed ability at best and regularly gassed them up My ops only and no slur on your ability
Pumaracing said:
It's curious to me how what one writes is apparently not always what someone else reads. Is this a cognitive disfunction in the comprehension of the reader or a failing in the clarity of expression of the author?
I propose a third option. Pumaracing is a troll.http://www.youtube.com/watch?v=dQw4w9WgXcQ
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