I have only just joined so i'd like to apologize for asking help so soon It first happened just after getting it on the road last month. I rode the bike for a couple of days with a slight misfire at low revs but i could rev through it, so all good. On the third day I went for a ride in the evening and filled up with fuel. The next morning it would only rev to 2100 and the just cut out. I have renewed the fuel filter, pre filter to the pump and checked and secured all the pipes. Still no reving above 2100. I changed the plugs and that seemed to cure the problem and I went for a great ride into suffolk and back home. After some food I went out again for another ride. Unfortunately the problem is back. Since then I have checked every electrical connection on the bike and cleaned with contact cleaner, even though they were all very clean. So it must be a part that is failing intermittently Any ides what could cause this symptom?.
Dude, this won't be much help but it could be loads of things. Does it tick over fine when running to start with, or would it stall if you just left it running?
Mine didnt stall,but it did have a cough/splutter.It also had play in the throttles,which I sorted and set the TPS.Runs fine now.
As said, could be so many things but just to clarify, you definitely checked all pressurised fuel hoses within tank for splits?
Thankyou for the replys guys. It starts fine and will continue ticking over with no problems. If I open the throttle and try to start it backfires into the airbox. I have become very conversant with all the components in the fuel tank since owning the bike and I'm sure that all the pipes, filter and pump operation are fine. I have researched the setting of the TPS and will be doing that this weekend
See if you can borrow a chip for the ecu. Some years ago my 748 had a similar problem where it just cut out as if the ignition had been turned off at 8k revs, changing over the chip sorted it and it's never been any trouble since. Quick and easy to do if you can get hold of a chip you know is good.
I have the standard chip somewhere and will search for it. I have new pipercross filters in the usual position
I am going into town to get an extraction tool from Maplins Does anyone have a spare chip to suit a 748 with micron pipes?
Thankyou for the offer Chris but unfortunately i'm in Essex Though if all else fails i would like to keep you in mind and i could get up there
Wouldn't worry too much about which chip for fault finding purposes, my faulty one was for "open pipes" and I just fitted the standard one back in, it's been there for about 8 years and 12k miles now with no issues at all. If the chip is the problem then of course you may feel happier with a re mapped one in there.
Just to try it, any 748 chip should do really. My '97 BP ran sweet with a standard chip and race cans. It could be the crank speed sensor. I've heard of more trouble with them than ECUs.
Found and fitted the original chip. Started and revved fine, and i went for a long ride. Behaved perfectly again. Got home turned off. Started it again still sounded great. Unfortunately went back to the bike about an hour later and back to cutting out at 2100! So it seems the intermittent problem is still there. Back to checking the TPS and crank speed sensor.
