Misfires when warmed up- advice please.

[rvfspr]

Hello all,

I have an RVF, it starts 1st time of the button and runs very smoothly to start with.

However when it is up to temperature it starts to misfire on at least one cylinder.

Is this a fault that someone has come across and can give some advice on before I start forking out for new plugs and coil packs etc??

Thank you
Scott

[rvfspr]

Any advice is appreciated

[CMSMJ1]

can you ID which cylinder and is it definitely a misfire rather than some other random noise?

I would check your HT leads are secure, that the earths are secure and try to figure out which cylinder and at what temp this is happening.

plugs are known for benig fragile so it could be breaking down under temp and missing??

[MexicanGringo]

If it runs smooth initially then its prob not an electrical problem, tho as CMSMJ1 said these plugs are delicate.. At what rev range does it mis? By mis do you mean a regular interruption to the usual firing.. Any changes to engine recently like a service?

[wullvfr]

is it possibly running rich?is the choke stuck open at all?

sounds like a problem with fueling as it happens when warm,but runs fine whilst cold.

double check electrical components just to rule them out.



wull

[rvfspr]

Thanks for the advice guys,

Its definately a misfire, but im having a problem identifying which cylinder as by the time ive got the rear fairing a nd tank off the bike has cooled down and runs properly.

The bike itself is not overheating and the two spark plugs that are easy to get to look to be in good condition so I guess need to try checking the harder plugs to reach! I have a feeling it may be one of the coils breaking down when it gets hot.

The only recent work to the bike is a new battery............ hmm I shall persist!

Thanks again.

[mambraNC30]

Check if all the cylinders are firing by checking the tempreture of each down pipe. the wet clothe test...

[abrmoto]

Does it run fine when on the road?
Could be a leak on vacum pipe to fuel tap if not, running out/ restricted fuel flow. had this on one on my RVF before now.

[Neosophist]

Check if all the cylinders are firing by checking the tempreture of each down pipe. the wet clothe test...

I had a missfire once, held the pipe and it was cold, without thinking I held the other pipe.. had white burn on my hand for days! *ouch*

Expensive yes but get a new set of plugs in there first :) Fragile plugs

[mambraNC30]

I had a missfire once, held the pipe and it was cold, without thinking I held the other pipe.. had white burn on my hand for days! *ouch*

finger lickin good KFC.

Expensive yes but get a new set of plugs in there first :) Fragile plugs

remove the plugs and clean all four of them first and check if you get spark from all four of them. if not then buy a new set. then go from there.

maybe the missfire is caused by a cylinder getting to much fuel and fouling the plug.