Strange misfire then too fast idle
 

Hi all,

Went for a nice Sunday ride this afternoon on the 748. Stopped the bike to go to cashpoint, went to restart and got quite a significant misfire the instant she fired up.

Once idling, everything seemed fine except the revs now sit at 2k (around 1,100 before). I carried on riding her for around 20 minutes. Power seems fine if opened up, but if crawling through town at 30mph in 4th or 5th gear, the misfire would occassionally come back - nothing major but definitely there.

The only other thing to note is that I thought by the time I ended my run (which finished with sitting in a bit of traffic for a few minutes) she seemed to be running warmer on the temp gauge than I would expect at this time of year (around 80°C). When I pulled up at the house, I turned her off and restarted and the revs still sit at around 2k.

She was serviced around 1500 miles ago with everything set up and synchronised correctly. Currently running 45mm open pipes, pipercross filter and JPH chip.

Is this the sort of behavior from a plug or plug lead breaking down or something more sinister?

Any help much appreciated

H

aint there some storys of the chips failing on open pipes then reverting to the standard setting ???

or could be just a pipe come lose from the tank that happened to mine on the way to the motogp the return pipe popped off and it ran high at idle

Update:

I have just replaced the JHP eprom with the original one (for standard pipes) and the misfire and fast idle has gone.

My questions:

Has anyone had a failure of a JHP eprom?
What are the Ultimap eproms like as a replacement. Am I right in saying they are programmable?

I have an ultimap eprom for my 916. Indeed it''s adjustable if you go to one of their dealers or you buy yourself the software/legacy cable and go to a dyno to set it up.

I have a 916 with termignoni 45's, BMC filter and 34/30 valves. Set the cams to 112/108 centers and bought their eprom for this setting and the result is awesome!!! No need for additional setup, bike runs great!

i was told that the 748's are poo poo when chipping there a real pain to get the right chip i got some pipes Leo vince and they came with a chip but the guys at carl harrisons said that it was a poo chip and sorted me out one that was correct for no extra cost i think there all chips which can be erased and programed if there just pics then they cant be overwriten ur best bet is to cotact JHP and see how much a chip is shouldnt be no more than 25 quid

good luck