Intermitant Problem NC30

[AndyJak]

Hi all. I came here in the hope of getting some help. My NC30 starts no problem. Revs clean etc and warms up ok. But as soon as I try to ride it and give it a handful of revs, the bike dies. Literally feels like a fuel problem, but it seems to happen too fast for fuel. I have a a HRC fuel cock fitted (no diaphragm or vac pipe) and the bike was fine previously. In my garage it will start ok, but as soon as you rev it a few time upto about 8-12,000 rpm it starts running rough again (like it's running out of fuel or cutting to 2 cylinders). This happens every time now. I have a de-ristrictor box fitted nect to the ECU and and I have tried it with and without that box. On the road, everything feels fine until I open it up and it kicks in, cuts out, and generally feels like there is loose connection somewhere. But I have checked everything I can.

Has anyone come across this type of behaviour before? It is very frustrating. I can feel the bike wanting to pull and free itself and occasionally it does only to cut down again and feel like its running out of fuel or going onto two cylinders.

regards
Andy

[CMSMJ1]

SO..how sure are you that the tap works properly?

We'll sort it, I am sure..

[AndyJak]

SO..how sure are you that the tap works properly?

We'll sort it, I am sure..

With the tank off, if you turn the tap to on or reserve it flows out very nicely. For some reason I keep thinking there is a some sort of electrical problem. The way it revs nice and then as soon as you go past say 8000 rpm it reverts back to the feeling of firing on two or running out of fuel. It stays like that until cooled off. Then it will start again no problem and rev ok until the same happens. On the road it cuts in and out like a loose connection. Totally baffled. Can anyone help me please?

[magg]

Can you measure the battery voltage when you rev the engine and the problem occurs.

[leef82]

Sounds electrical, check your regulator rectifier, earth leads etc. Also if you could fit a standard fuel tap that'll rule that one out , probably no need for hrc tap on the road

[AndyJak]

The HRC tap does it's job. It wont be that I am sure as the bike was running fine previously with it. I also use the bike on the track anyway. Nope I think it is something electrical. Possibly the ECU/CDI failing? Anyone got a spare I could try out? Pretty please?

regards and thanks,

Andy

Lincolnshire.

[AndyJak]

The HRC tap does it's job. It wont be that I am sure as the bike was running fine previously with it. I also use the bike on the track anyway. Nope I think it is something electrical. Possibly the ECU/CDI failing? Anyone got a spare I could try out? Pretty please?

regards and thanks,

Andy

Lincolnshire.

[AndyJak]

I also noticed today when I left the bike ticking over, occasionally revving a little (it revs clean up until I go over 8000 rpm or thereabouts.) that the regulator is boiling hot. Should it get hot? Too hot to touch.?

thanks
Andy

[magg]

Short answer, yes. Have you measured the battery voltage when the engine is running above 5000 rpm.

[AndyJak]

Short answer, yes. Have you measured the battery voltage when the engine is running above 5000 rpm.

No not yet. But I have a mechanic in work who will check these things for. What I can't understand (having messed with bikes for 30 odd years) is the fact that the bike is fine until I rev it abouve 7-9000 rpm and then it cuts to two cylinders I think (hard to check by touching already boiling hot down pipes). This is repeatable every time it cools down again or has been switched off for ten minutes. What could possibly be making it go onto two cylinders? Limp mode possibly? CDI on the way out?

Anyone got a spare cdi I could borrow? pretty please?