I need some advise. My bike was off road for about 5 weeks due to having the front forks rebuild. When I picked up the bike it was a pig to start. I eventually got it running and drove it home. Since then I have been unable to start it.
I have put a new air filter in it along with new plugs. I have a healthy spark. There is fuel getting to the carbs, but when I try to start it it just turns over without any sign of catching.
Have you tried a whiff of Start Pilot or an other starter help?Is your battery fully charged and,of course,is the on-off contactor on the “run” position?
Hi Fred ,
Thanks for the reply. The battery is healthy so the problem is elsewhere. I have never been a fan of any type of spray start as I feel that it just masks the problem. However, I will have a go and see if it helps. Yes the run button is on.
try putting a jumper wire in the petrol pump relay connector, it may be that the petrol that is getting to your carbs is just what is siphoning past your petrol pump and not under pressure,
Thanks for the reply. Looks like I need to do some digging. I didn’t know it had a fuel pump! Ok where is it and where’s the relay?
the relay is behind the left hand side panal, pull the multi-plug out of the relay then push a piece of wire in the plug making connection with the black and white wires, this effectively bypasses the relay, turn the ignition on, you will probably hear the fuel pump start clicking, then try start the engine. the pic below is of a fe, the ff is in the same place.
I had a problem with my VF1000R E which was impossible to start even with fresh petrol and good sparks. The bug was caused by a loosy connection on the small connector direct from the pump. When the pump was tested as Pete says, every thing seemed alright but, as soon as the starter was used and the engine crancked in rotation, the connection loosened and the engine would not start. That’s why I suggested the use of Start Pilot which would prove that ignition,timing and sparks are both ok and the problem resides in the petrol feeding system…
Thanks for the picture. That’s made it very clear, I will have a look this afternoon. By the way what’s that clean silver rail in the top of the picture? I have something similar but mines got a lot of rust on it!!!
Just did the bypass and up she run!! So it looks like the fuel pump relay was at fault. I will get another and hope that cures it. One other thing is that I now need to find out why the bike won’t tick over without full choke. I fear that it could be the carbs needing a clean. Classics! Don’t you love them. 4 carbs in an impossible location. Crap!
Thanks for your help
The carbs are not easy to take off but quite easy to replace when you put the rubbers in boiling water prior operation!Cleanning the carbs is a chore but as to be done…
good to here its running, as fred says the carbs can be a pain to get off especially if they havent been off for a while…
theres just one thing i would check though before pulling the carbs off, just check to make sure you have a good spark on the front 2 cylinders, there is a problem common-ish to vf’s where the CDI fails (or the wiring to and from it) this effectively shuts down the petrol pump relay and the front 2 cylinders… it probably wont be it, but for the sake of a few minutes taking the plugs out i would check.
hope all goes well, and keep us posted.
Thanks for the info Pete, I will try anything prior to removing the carbs, it’s not a job I’m looking forward to doing, but needs must!
I will let you know how I get on.