Misfiring Merlin V24
Discussion
Ok its a 4 stoke Honda on a lawn mower but to get your attention 
It starts fine and stalls after a minute or two, sometimes back fires. Always restarts after, sometimes seems to over rev. Once its really warm its runs fine. I've checked the plug is clean, assume there's no engine management so what controls the timing? Any ideas gratefully received!
Oh incase you haven't noticed I'm a bit of an engine amateur but am interest to learn on the lawnmower!
It starts fine and stalls after a minute or two, sometimes back fires. Always restarts after, sometimes seems to over rev. Once its really warm its runs fine. I've checked the plug is clean, assume there's no engine management so what controls the timing? Any ideas gratefully received!
Oh incase you haven't noticed I'm a bit of an engine amateur but am interest to learn on the lawnmower!
rich 36 said:
No its my being facetious.
I expect a boffin will be along shortly however,
how old is the petrol your using, if its last years, it ma) be worth adding some fresh
Richard
Yes the petrol is ancient, I'll try some fresh, I'm going to service the thing at the end of the season so I'll probably have to take it to a repair shop after that anyway!I expect a boffin will be along shortly however,
how old is the petrol your using, if its last years, it ma) be worth adding some fresh
Richard
GreenV8S said:
I assume it's running a carb of some sort, and I assume there's some sort of cold start enrichment, and perhaps this isn't working quite right.
Thanks for the post yes there is a cold start, the throttle extends to go into cold start, I'll look at the cable and see if its stretchedEdited by Aggi on Sunday 9th September 22:34
stevieturbo said:
just because the plug looks ok...means nothing. Replace it and see....its not like there are 24 to replace !!! lol
Did wonder, its 4 years old and its clean but guess that the cleaning has widened the gap. Think I'll change the oil, petrol and plug and see if it improves. Thanks for the posts chaps!Aggi said:
Ok its a 4 stoke Honda on a lawn mower but to get your attention
It starts fine and stalls after a minute or two, sometimes back fires. Always restarts after, sometimes seems to over rev. Once its really warm its runs fine. I've checked the plug is clean, assume there's no engine management so what controls the timing? Any ideas gratefully received!
Oh incase you haven't noticed I'm a bit of an engine amateur but am interest to learn on the lawnmower!
Unless it has a battery and a dynamo, it probably has a magneto. The relationship between the coil and the magnet controls the timing. If you have such an arrangement then you'll probably find some slotted bolt holes that allow the coil or the magnet to be moved, and thus change the timing.It starts fine and stalls after a minute or two, sometimes back fires. Always restarts after, sometimes seems to over rev. Once its really warm its runs fine. I've checked the plug is clean, assume there's no engine management so what controls the timing? Any ideas gratefully received!
Oh incase you haven't noticed I'm a bit of an engine amateur but am interest to learn on the lawnmower!
Edited by dilbert on Monday 10th September 02:06
I though there was going to be a pic of 2 merlins conjoined to make a real monster.......
sounds like a fuel issue to me, drop the float chamber off the carb and see if its full of gunk, also check the air filter, if its paper, renew it, if its sponge, rinse it out in petrol or carburettor cleaner, then soak it in oil, (squeeze out the excess though) and re use. re fill with fresh fuel and you should be ok
sounds like a fuel issue to me, drop the float chamber off the carb and see if its full of gunk, also check the air filter, if its paper, renew it, if its sponge, rinse it out in petrol or carburettor cleaner, then soak it in oil, (squeeze out the excess though) and re use. re fill with fresh fuel and you should be ok
ELAN+2 said:
I though there was going to be a pic of 2 merlins conjoined to make a real monster.......
sounds like a fuel issue to me, drop the float chamber off the carb and see if its full of gunk, also check the air filter, if its paper, renew it, if its sponge, rinse it out in petrol or carburettor cleaner, then soak it in oil, (squeeze out the excess though) and re use. re fill with fresh fuel and you should be ok
Thanks will give that a go at the weekend!sounds like a fuel issue to me, drop the float chamber off the carb and see if its full of gunk, also check the air filter, if its paper, renew it, if its sponge, rinse it out in petrol or carburettor cleaner, then soak it in oil, (squeeze out the excess though) and re use. re fill with fresh fuel and you should be ok
First get rid of the ancient petrol.
Check that all the throttle linkage / cold start linkage is moving freely as it should and not
binding or failing to move far enough or not moving at the right point etc. etc. etc. These combined throttle/choke linkages are an absolute abortion and a pain in the arse and cause no end of silly problems. There are far fewer problems when these engines are fitted with separate throttle and choke controls.
Check that all the throttle linkage / cold start linkage is moving freely as it should and not
binding or failing to move far enough or not moving at the right point etc. etc. etc. These combined throttle/choke linkages are an absolute abortion and a pain in the arse and cause no end of silly problems. There are far fewer problems when these engines are fitted with separate throttle and choke controls.
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