I have owned my `04` viffer for 3 months now and almost since the first day it has had a strange misfire problem,and despite going back to the dealer where i brought it,they can not get to find it a cause or even replicate it.It is a very intermittent problem that can go sometimes 2 weeks between occurences and it always starts with a audible `popping`sound from under the fuel tank,then as you open the throttle there is a bad misfire between 4000 and 5000rpm then it corrects its self and the power comes in with a bang(far worse than the vtec cutting in).It can happen at any temprature and at anytime,sometimes once in the journey,sometimes almost coninuoslyThe bike is in standard trim apart from a Power commander III and a set of Scorpion cans.Any ideas would be gratefully received.cheers glynbo.
I'm not a mechanic, but I'll offer this up as a possible cause. Perhaps your timing is slightly off, and when you open up the throttle, the spark is not in sync with the cylinder head position. I know that most often in a car or bike, if the timing is off, you'll notice it most at low RPM's, than after alot of popping and gargling, you wont be able to tell as much once the motor is revved up high enough. Hopefully this helps you or others get the creative juices flowing in terms of what the problem is. Good luck to you.
Spark timing is built into the CDI box and cannot go wrong. Could there be a fault with the VTEC cam timing ??
Thanks Daniel and Squirellman,for your thoughts,i will mention it to the technicians at the dealer were i brought the bike from but i would think if the timing was out in anyway i would have the problem all the time rather than intermittently.Someone has suggested that it might be a problem in the loom causing the misfire,then every so often when i hit a bump in the road it makes proper contact until it is dislodged again,sounds feasable to me but awkward to check out.Also they think there could be a problem with the power commander and maybe it is worth disconnecting it and using my bike for a while to see if the problem goes away.I will have to wait till Tuesday to try this out as my bike is at the dealers until then(on thier easter hol`s)cheers glynbo
