Loosing Power

[SouL]

Hay all

I've picked up what I hope is a small problem with my NC30.

Around 8000 - 10000 rpm, any gear the bike starts sounding all rough and stops pulling. Although in the lower rev range it seems fine. Would anyone have any idea what the problem may be? Is there any thing I should check?

Thinking that it could be fuel starvation....maybe the fuel filter or tank fuel tap needs a clean

Started doing it on the way back one of our bikes runs

[vfrman]

It definitely sounds fuel related. I would start with a check of the system. The filter and tap as you mentioned, plus the vacuum line for splits or cracks. Then balance the carbs. If it still lacks power, time to take the carbs off and clean them and set float heights. I am not sure what jets you have in there, but I am thinking the mains may be too small.

Good luck.

[SouL]

Thanks VFRman

problem sorted....sprayed an entire can of carb cleaner into the carbs and replaced the fuel filter, took off the fuel tank valve and inpected it for possible blockage which there wasnt any. Put it all back together again and took the bike for a ride and waaallaa all sorted!

[vfrman]

hmm. I wonder what it was then.

[SouL]

Ok I think I got ahead of myself....

Problem not sorted!

I have narrowed the problem down to definite fuel starvation!

The problem of the bike loosing power in the high rev range has seem to have gone away but now the bike is cutting out due to a fuel cut off some where.... the weird thing is.... the first time it did it I was rather far from my destination and refused to push the bike the entire way there. So after allot of cursing and ranting... I decided to get the b#tch started. After fiddling around I decided to undo the breather hose on top of the tank and blow as hard as I could. I tried starting the bike again and it started up like nothing was wrong and had no problem all the way back. Later on I got back onto the bike and it did the same farking thing! So blew down the breather nozzle and bike was back to normal again until I stopped the bike and started it up again later which I had to perform the same procedure!!!

I have a strange feeling that it could be the fuel tank valve? I had about 2 liters of fuel remaining in the tank which I have now filled up and the problem seems to have gone ( I think) May be now that with the extra amount of fue.... the fuel is under greater pressure to push down to the carbs?

I have a weird feeling that the fuel is not being allowed to flow freely through the tank nozzle valve?

I have now opened up and performed the following procedure which I hope will work

http://www.akhara.com/nc30/fueltapmod/index.html (Great website on some DIY)

[superlite]

I have now opened up and performed the following procedure which I hope will work

http://www.akhara.com/nc30/fueltapmod/index.html (Great website on some DIY)

The HRC mod will probably sort your problem if you've blanked off the vacuum hose spigot on the inlet manifold. Sounds like the vacuum hose was probably the offender to me.

Not the best mod for a roady though. Stick a dry break QR fitting between the carbs and tank if you can, so that you can turn the fuel off when you're not riding.

[SouL]

Mod still hasnt sorted out the problem...

Should I take out the fuel filter? Do I really need to have a filter what are the benefits? Will it make much different keeping the carbs clean after all the fuel tap has it's on filter

[Neosophist]

Mod still hasnt sorted out the problem...

Should I take out the fuel filter? Do I really need to have a filter what are the benefits? Will it make much different keeping the carbs clean after all the fuel tap has it's on filter

Yep you could do with it, it stops rust / sandy crap getting in the carbs and blocking the pilot jets up.

If you take the hose off and put it in an empty container and turn the tap on does the fuel flow freely?

You could have a blocked tank breather pipe which is causing vaccumn lock on the petrol.. try unscrewing the little breather off the top of the tank and riding see how it goes.

[skinnydog0_0]

I have read other posts on here about people having fueling problems with low fuel. Mine has the HRC tap mod, and it doesn't like running on reserve. As soon as i have to go to reserve it starts feeling very wooly, like it is only firing on 3. as soon as i fill her up it is fine. try getting more fuel in it might be that simple.

[SouL]

Yep you could do with it, it stops rust / sandy crap getting in the carbs and blocking the pilot jets up.

If you take the hose off and put it in an empty container and turn the tap on does the fuel flow freely? .

Yup...Yesterday I rode the bike for over 10km's and then it started dying on me, I then stop the bike (on the motorway!) blow down the breather nozzle and bike rides as if nothing had happened

You could have a blocked tank breather pipe which is causing vaccumn lock on the petrol.. try unscrewing the little breather off the top of the tank and riding see how it goes.

I took the breather pipe of yesterday and blew through it fine same with the valve. I've taken the breather valve apart and all seems fine. But will take your advice and leave the hose off. I've also fitted a smaller fuel filter as I was previously I was using a car filter and it was slightly too big causing the fuel hose to bunch up beneath the tank.