nc35 dies after about 10 mins

[littlebigman]

Hi Chaps,
bike recently died due to dead battery,sorted that but bike was brought home on back of AA truck.Since then bike runs on idle for 10 mins or so then dies or after about 3-4 miles riding.Sounds like fuel starvation??There was water in breather but cleared that and still the same.If left overnight with fuel tap 'on' there is a damp/sweaty patch at base of side stand which smells like fuel. Could something have been dislodged or broken on the AA truck? Any thoughts would be appreciated.

[james66]

Hi mate seems like it would be more of a coincidence that this has happened at same time as having to recovered,
Have you checked fuel tap vacuum is working? Pull of both the fuel pipe + the vacuum pipe, suck the vac hose + see if a good stream of fuel is flowing, if so tap is ok, check the vac hose isnt split or perished as the vacuum wont get the the tap if it is, if all that is ok id look at a blockage in the float valve filters, if it dies + your at home unscrew the float bowl drains + if little or no fuel comes out + the tap is ok then is will be float valve filters, its unlikely that it will die on idle as even with a partial blockage it can flow enough to idle
hope this helps

[CMSMJ1]

check your oil asap - if it stinks of petrol you have a minor ballache to sort out..

[littlebigman]

Thanks guys.Hope its just a blockage or pipe perished etc,

[CMSMJ1]

if you have petrol in your fuel then you need to sort it..and it will be a leaky carb needle valve 9 times of 10.

easy to fix...

[littlebigman]

Oil does smell a bit like petrol.

[CMSMJ1]

hmmm

lol - so, it shouldn't smell like petrol.... is it pretty thin looking...?

it is a fairly common issue - I've had it..most of the guys who have been here some time have had it or assisted with someone else to sort it..

Solution is to give the carbs a tap and see if you can seat the float valve..or if no joy, strip that carb and clean it - easier than it sounds.

Either way, fuel in the oil does not good oil make...and so it needs changing.

[littlebigman]

Would a carb problem explain the strong smell a fuel and the slight leak if fuel tap is left on?

[Morespeedvicar]

The vacum feed to the fuel tap should stop fuel flowing unless the engines running so maybe rebuild the fuel tap aswell, unless its been HRC modded? Prob just wants cleaning out.

[CMSMJ1]

Yes it can.

You have a couple of options.

1 the fuel tap is knackered or has been "HRC modified" so that is is always on. Usually it needs a vacuum to open.

If the tap is always on then the float valves are the only things stopping the fuel running into the engine and if they are leaky or have some shit in them stopping them closing (more likely) then the fuel will trickle itself out your tank and into the top of your engine....down the bores and into the oil.
If you are unlucky it will dribble into the combustion chamber and sit there and when you try and start the bike it will have a hydraulic lock and that can really screw things up.

So, best case - you need to check the fuel tap and flow - and to give the carbs a rap to see if you can reseat the valve.
worst case - it has pissed fuel through the motor, washed the bores and is ready to hydraulic lock next time you start it..