2008 Te450 Fuel Issues

[-Norwegian-]

Hello!

I'm having some issues with my '08 Te450 after a complete rebuild/restoration of the bike.
The bike has not been in running condition since 2019 due to an incident where all the splines on the countershaft were completely stripped out by the front sprocket, requiring to split the cases in order to replace the broken countershaft. I began the teardown shortly after this happened, but never got around to getting the engine back together, so I ended up letting an authorised workshop put it back together for me back in november. I have now managed to put the bike mostly back together, however when I tried to start the bike it idled for a couple of seconds before it just stalled and died.

The fuelpump primes as normal when the key is turned or the killswitch is depressed, no strange noises or anything, just normal. The electric start works as it normally would, the bike cranks over and it fires up rather quickly. The bike idles for about 8-10 seconds before it shuts off again. It will then not fire back up until the killswitch or key is switched off and on to make the fuelpump prime again. If one tries to rev the bike during those 10 seconds it just bogs and coughs and does not raise much in rpms.

I have checked all the fuses and they are all ok. I have also checked for worn cables and bad connections, but have been unable to find anything of note.
I'm guessing the issue is fuel pump related, bit I still find it weird that it primes normally when the key is turned?

If anyone has any tips or ideas as to what could cause this issue, I would be very grateful.
Best Regards!

 

[hhdwtmtw]

I've not seen this issue before. Weird. I can't think of a reason for the ECU to cut the fuel after 10 seconds but the fact it won't rev above idle is a likely indication of the problem.

1. I would plug in iBeat to see if any codes are present (assuming iBeat works with this bike).
2. It could be the fuel pump or pressure regulator. A fuel pressure tester inline when it's running would confirm or eliminate this. Maybe try some starter fluid once it's started to see if extra fuel helps it to rev.
3. Does it still have spark after 10 seconds?
4. It could be a sheared woodruff key on the flywheel throwing the timing out.

I always work on the 4 things needed for an engine to run: Fuel, Compression, Timing and Spark.

 

[-Norwegian-]

I've not seen this issue before. Weird. I can't think of a reason for the ECU to cut the fuel after 10 seconds but the fact it won't rev above idle is a likely indication of the problem.

1. I would plug in iBeat to see if any codes are present (assuming iBeat works with this bike).
2. It could be the fuel pump or pressure regulator. A fuel pressure tester inline when it's running would confirm or eliminate this. Maybe try some starter fluid once it's started to see if extra fuel helps it to rev.
3. Does it still have spark after 10 seconds?
4. It could be a sheared woodruff key on the flywheel throwing the timing out.

I always work on the 4 things needed for an engine to run: Fuel, Compression, Timing and Spark.

Alright, I've had some time to do some more troubleshooting today.
Turns out the issue is actually spark related. The bike starts up, runs for 10 seconds then spark is gone. The spark will only return after turning the key off and on again, or pushing and releasing the killswitch as mentioned in the original post. I've read through multiple threads about spark issues, and a common fault to check is the green/red wire(Connected to coil, injector, fuel pump assy and relay) and white/red wire(Between Coil and Cdi) for shorts/fraying/bare-spots.

I did some poking around with my multimeter and sure enough I found out that there is a short between the green/red wire and chassis-ground. I guess I will just have to dig into the wiring harness a bit more and try to find out why it's shorting out to ground. As it is now, when the green/red wire is connected to the coil there is continuity between the two spade connections on the coil, basically shorting both green/red and white/red to ground. If I remove the green/red spade connector from the coil there is no longer continuity between the two spades on the coil or between either spade on the coil to ground. Just continuity between green/red wire and ground.

I'll add a photo if it helps to visualize. To avoid confusion, the black wire with red crimp-spade connector in the photo is one of the previous owners attemt to extend the white/red wire. This sort of crap is all over the wiring harness on this poor bike, so I'm not surprised when there are some electrical issues with it.



While I'm at it, does anyone know if the two spades are connected the right way around on the coil? I'm guessing that is also important.

 

[hhdwtmtw]

Great to hear you have narrowed down the fault.

A trick I use for shorts is to wire a 12v test lamp between 12v on the battery to the shorted wire. The bulb will be lit up. Then gently wiggle around the loom until the bulb goes out.

 

[-Norwegian-]

Great to hear you have narrowed down the fault.

A trick I use for shorts is to wire a 12v test lamp between 12v on the battery to the shorted wire. The bulb will be lit up. Then gently wiggle around the loom until the bulb goes out.

Yeah, I have one of those as well. My multimeter also has a built in function where it will beep whenever there is continuity between the probes, so that's what I plan to use. Hopefully the issue will be resolved soon!