NC30 - Felt Like it had run out of fuel.

[IanP]

Me Again..

I'm also thinking of running some redex through the system. I've read somewhere that this can cause the carbs to bung up. Can anyone shed an light on to this?

Thanks

[IanP]

Update:

So I took the bike and tank apart. Found loads of crap in the tank. Check all the lines they seemed fine put it back together. Battery was dead so needed to bump start it seemed to be running fine. Went out a few times, battery charaged. Now it starts first time.

So as today is a lovley day decided to take it out for a ride done about 100km just on the way home and was over taking a car and just lost power again. Dropped it down a gear as I was losing revs and power then heard a loud bank from the exhaust and continued to lose power. I was able to rev the bike but it was reving so slowly and no power. Didn't see any smoke but I was more worried about getting hit by the car. Any Ideas?

Thanks

[Cammo]

A dodgy electrical system can show up as all sorts of problems. It can cause a weak spark, leading you to think it's a lot of other things responsible for your problems. There are some easy checks to rule this out.

Check the battery voltage at idle and at 5000 revs when you get it going again. It should be over 13.4v. Also take a look at the wires and plugs that go into the reg/rec (LH side of the subframe, under the seat unit) you can often see early signs of burnt wiring etc.

[Cammo]

Update: Dropped it down a gear as I was losing revs and power then heard a loud bank from the exhaust and continued to lose power.

The backfire will be because fuel is still getting through to the exhaust.

I don't think your problem will be carbs as usually you'll just lose a % of power (e.g. 1 or 2 carbs) but it will still run. Forget the redex.

[IanP]

A dodgy electrical system can show up as all sorts of problems. It can cause a weak spark, leading you to think it's a lot of other things responsible for your problems. There are some easy checks to rule this out.

Check the battery voltage at idle and at 5000 revs when you get it going again. It should be over 13.4v. Also take a look at the wires and plugs that go into the reg/rec (LH side of the subframe, under the seat unit) you can often see early signs of burnt wiring etc.

The backfire will be because fuel is still getting through to the exhaust.

I don't think your problem will be carbs as usually you'll just lose a % of power (e.g. 1 or 2 carbs) but it will still run. Forget the redex.

Thanks the for replay. Yeah I was thinking it maybe a electrical, first thought was the coil. It was running but lumpy I think if I would have stayed on a flat road I could have kept it going. Also it seems to happen when the bike gets hot.

I test it and let you know my findings. Thanks for the help.

Ian

[Cammo]

If it's a heat related problem then it could be the fuel vacuum line. This attaches to the downwards spigot off the fuel tap, and runs to the back/rear cylinder intake.

When it gets hot it can collapse providing no fuel flow.


Don't mean to point you in a different direction, but obviously there can be a fair few culprits of your problems.


The coils on these things are fairly bulletproof, but happy to be proven wrong as always!!

[IanP]

Update #99999

So I couldn't get her started when I went out to test, I noticed the indicator relay was making a loud clicking noise unpluged it and it started second attempt (Very Strange ). Tested the battery when Idle and then at 5000RPM Dead on 13.4.

Maybe it is the fuel lines under heat, the mystery continues...

[IanP]

Hi Guys,

Just a little update.

I replaced the fuel line (the old one seemed fine to be honest).


Part number 7.

Also replaced the spark plugs noticed the old ones were covered in oil. More like pulling the dipstick out than spark plugs.

Havne't riding it yet but I think the problem is still there to be honest.

[Deviant400]

on my bike i have the main fuel line "Thick pipe" ,and a "thinner pipe" comming off just below that points off the same way as the thick one but i have a spiggot pointing down , but no pipe attached to this should there be a pipe connected to this ??

[Polisher]

Mine has the larger fuel pipe facing forward and the vac pipe (thinner pipe) running same direction. The vertical pointing take off has nothing connected.

Bike runs really well but sometimes when its hot it gets a bit 'lumpy' at low rpm but still revs out ok. At tickover when both cold and hot it seems to 'hunt' a bit. Its standard apart from a race can. Any suggestions, would looking at the jetting or syncing up the carbs help, or maybe valve clearances?

Dont get me wrong its not bad, but I want it perfect

Cheers, Neil