I took the bike out tonight, it hasn't started in a week or so so the battery was flat. I jumped it off the car battery, rode away and immediately it started playing up. It was juddery, stalled at a round about, the efi light came on and off many times, rapidly whilst problems were happening, clear when not riding. No error codes stored in the dash. It would judder when I opened it up, it stalled on the over run. Occasionally sounded like it was running on one cylinder on and off. It rode like it had square wheels. I thought maybe it was the relay had got wet again as I still haven't found that leak but it hadn't. I cleaned it andcovered it with a finger from a rubber glove just in case. Not sure where to go from here. Today I refitted the fuel pump assembly and seal. That went together with no problems, the bike spent a week with no tank, panels or seat but nothing else was touched. I put everything back as it should be as far as I can tell. Can you help please?
I'll strip the fuel tank off again tomorrow and have another check over. Effing pain in the ass Duke.
When you jumped it off your car you didnt have your car running did you as this can cause ecu problems. Perfectly safe it isnt running though.
No, the car was not running. It's on the trickle charger now. Also the battery wasn't completely dead, was 11.2v on the dash after attempting to start, so I don't think it's knackered. It's only a couple of months old. It must be the tank incorrectly fitted. Would that throw up an EFI code though?
Tom When you refitted the fuel tank did you fully engage the socket for the electrical connections? Just a thought!
I hope you haven't fried part of the ECU Tom jump starting directly from a car battery is not recomended Others will say no problem but in the most part I disagree (from personal experience ). have you checked all fuses , and take out coil packs an plugs to see if they are both sparking if you think it's running on one cyl
What about the fuel line connections as they are both the same could have the feed and return wrong way round?
They are the same size connections, but did you fit the pump back the right way? There is a stamped marking saying front on it.
The fuel pump is definitely fitted with the 'front' marker pointing forwards. I have the hoses attached to the same pipes they were fitted to before but I could probably push the hoses on a bit further. The more I think about it the more fuel starvation sounds likely. Wouldn't a fried ecu mean it runs with a continuous error? This one comes and goes. I need to do some testing rides tomorrow but I think hard acceleration causes the issues. Is there a procedure I can work through to isolate the problem?
Tom I think you have already identified your problem as you said "Occasionally sounded like it was running on one cylinder on and off. " Just thinking about what could cause this, you haven't pinched the vertical cylinders coil pack wires in between the tank and one of the camshaft cover's fixing nuts have you, and damaged the wires?
749/999 models did suffer from rust/corrosion inside the tank if stored with fuel in causing a silt type substance gathering in the bottom of the flange and clogging the pump, in theory you cannot dismantle the unit but it is possible to get the pump out of the housing to inspect. other option is to check fuel pressure i think it should be about 3bar
Check for pinched wire to coil as mentioned above and also worth checking the fuel lines are not pinched. Re-check the wiring connections to coil and pump and charge the battery. These things like eating batteries and if its weak you will find it susceptable to all sorts of little gremlins. Ive had similar issues but they just went away. Could it even be water in fuel? Check it over, charge the battery and go out and thrash it and see if it does it again. I bet its just telling you off for having it in bits.
So true, mine does the same every time I take it to bits. And 99% of the time it's because I've not connected or trapped something.
Do you know what condition the coil packs are in, particularly worth a check of the front for water ingress. My other suggestions have already been mentioned
I had the front coil off a couple of weeks ago and it was perfect. I hadn't fitted the hoses to the fuel pump fully so that maybe it. All other connections were sound. Also I used Vaseline to fit the fuel pump o-ring. Didn't think that would knacker it though as I googled it before hand and the Internet said don't worry. Off for a ride now so I'll soon find out if that's what it was.
Still broke. Firing on rear cylinder only. Luckily I'm at Moto Rapido so couldn't ask for a better place to break down
