occasional misfire

[DVH]

a 2003 v11s has a slight miss between tickover and 3000rpm on a light or constant throttle. would only miss once then continue no problem for couple of mile before missing again, when it misses it doesn't show on the tacho. a bit touchy on wet roundabouts.

It has had a set of mistral cans ( e marked ) and the fuel system etc set up at the dealer.

Above 3000rpm or opening throttle no problem. the fault cannot be produced at will, was ok until cans fitted.

can this be put down to the new cans or should I be looking for a fault elsewhere. Does ECU record error code to help trace this fault.

[Guest davidb]

So did mine. I was trying to lean it up by messing with the tps with different setting. (went back to stock) and when I rode it , it was missing. I re balanced the throttle bodies and now it is fine.

[Bilby]

a 2003 v11s has a slight miss between tickover and 3000rpm on a light or constant throttle. would only miss once then continue no problem for couple of mile before missing again, when it misses it doesn't show on the tacho. a bit touchy on wet roundabouts.

It has had a set of mistral  cans ( e marked  ) and the fuel system etc set up at the dealer.

  Above 3000rpm or opening throttle no problem. the fault cannot be produced at will, was ok until cans fitted.

can this be put down to the new cans or should I be looking for a fault elsewhere. Does  ECU record error code to help trace this fault. 

37306[/snapback]

I've had my Roso Corsa back under warranty and the TB's balanced etc. It still misfires with a loud bang....only occassionally below 3K or under even throttle. So noone is alone, but if someone, anyone, comes up with an answer, please let me know. Other than that....I luuuuuuuuuuvvvve this bike and the gobs of torque it delivers so willingly.

[Baldini]

All joints on exhaust system, inc front balance pipe tight/leakfree?

[Bilby]

All joints on exhaust system, inc front balance pipe tight/leakfree?

42240[/snapback]

Thanks Baldini. I think everything is fine but will check it all on the weekend. PS Like the photo

[jimbemotumbo]

Could also be a lean surge, common at that rpm under light throttle. I had it at 3k and chased it around the rpm range via PCIII mapping changes. Finally caught up with it and it's gone. Only became apparent after I put on the M4 cans. of course your tps and TBs need to be correctly set up too, as everyone has said.

 

Try riding at 3k with a bit more throttle, or accelerate from 2800 through 3200 rpms. If it goes away, then it's a lean surge and not a misfire.

[bmc5733946]

I have posted this before but will reiterate. Check the plug caps, 5k ohms is right, many will be open or out of spec, causes misfires at low speed and sometimes at high load, may also misfire throughout range. Engine may be impossible to balance or be incorrectly balanced if slightly misfiring at balance RPM 2-2.5k we keep spares on shelf. I carry a spare on the bike or switch to Magnecor wires which are much more durable in resistance value.

BMC

[Mike Stewart]

I think you are lean. When I put Mistrals on my 03 Rosso, the bike ran badly. The PCIII was the only way to correct the problems. Of course this is in the old good USA, which has no O2 sensors.

 

Mike

 

a 2003 v11s has a slight miss between tickover and 3000rpm on a light or constant throttle. would only miss once then continue no problem for couple of mile before missing again, when it misses it doesn't show on the tacho. a bit touchy on wet roundabouts.

It has had a set of mistral  cans ( e marked  ) and the fuel system etc set up at the dealer.

  Above 3000rpm or opening throttle no problem. the fault cannot be produced at will, was ok until cans fitted.

can this be put down to the new cans or should I be looking for a fault elsewhere. Does  ECU record error code to help trace this fault. 

37306[/snapback]

[Bilby]

Could also be a lean surge, common at that rpm under light throttle. I had it at 3k and chased it around the rpm range via PCIII mapping changes. Finally caught up with it and it's gone. Only became apparent after I put on the M4 cans. of course your tps and TBs need to be correctly set up too, as everyone has said.

 

Try riding at 3k with a bit more throttle, or accelerate from 2800 through 3200 rpms. If it goes away, then it's a lean surge and not a misfire.

42357[/snapback]

Reckon you are correct jim. From what you said it sounds like what you said. I'll take it to the dealer and get em to check it out.

Cheers

T

[Guest Corsaman]

I have a '03 Rosso Corsa, and had the same low RPM spit back through airbox, I sent it back to the dealer , In Auckland, New Zealand, and they found the cure was to remove the Landos probe (sp)(oxygen sensor). This was not dis-connected at the exhaust cross-over, but was disconnected somewhere else in the wiring circuit.

This solved the spitting back immediately, but have since fitted carbon fibre Mistral's and a PC3 and had it set up on the dyno. I have also taken rubber snorkels off the front of the air box.

 

I am now very happy with the way it runs. and sounds.