hiya folks. just dopped the engine back in my nc 29 after having new crank shells. theres just a few more things to iron out then shes sweet as a nut.
my bike stinks of fuel, which isnt good, alot of people say its normal for nc29s to smell like fuel , but i gatherd if you can smell fuel, something obviously isnt doing its job, correct?
at first i thought it was leaky float bowls, so i wipped the tank and carbs off, connected up the tank to fuel pump, and switched the ignition on to fill the carbs up to see where they were leaking, but from what i can see, i dont think its the float bowls that are leaking, but its hard to tell with petrol beacuse it kinda spreads before it runs.
couldd it be possible that an o-ring has failed somewhere, like around where the fuel line connects to the carbs on the little t-shaped connector or somewhere along there?
if someone has replaced the o-rings in these carbs before, what is the best way to do it?

another thing is, there is an awefull knocking on the final drive, but the spockets and chain are fine, but the cush seems rather wobbly, there is some back to front free play and side to side. could this mean that the rubber and the bearing are worn? ive heard of packing out the cush rubber by wrapping an even amout of insulation tape around each of the teeth the slot inside the rubber as a tempory measure, would this work?

thank you for your time.
josh.

Assuming you've done the obvious and checked chain tension etc, and you haven't managed the impossible and created a tight spot when putting it all together, then it is most likely a crushed/flogged wheel bearing. If your cush drive is knackered I wouldn't bother wrapping in electrical tape, source a replacement. I have to admit though, I've never come across a flogged cush drive.

Fuel leaking, It may be worth checking your float heights are set correctly. Don't forget to check the fuel tap is screwed into the tank too. I put my bike together once and overlooked that until I put petrol in the tank................

okie doke, yes the chain is set at the correct tension, i will check the wheel bearings.

I thought the float height wasnt adjustable on NC29 carbs .Theres deffinatley fuel leaking from the carbs, but it might be worth me checking the fuel tap to.

cheers.

floats arn't adjustable on 29 but worth checking and replacing if not correct also check the fuel line from the pump to the carbs i had a small rip on mine which was spraying on the float bowls making me think the bowls where leakin only sussed it after doin gaskets twice

Cush drives do wear and when worn you feel a wobble as you do fast up gear changes under hard acceleration. I cut some hard rubber to pack out mine as a temporary measure. Remember it has to transmit the force of the engine turning the rear wheel!!! (so tape is a no! no!) New ones are ~£5 each, so that's £25 for a set of 5, better than second hand ones from ebay that are bound to be worn too!

On your leaky carbs, it can also be dirt in the float valves, not just the float height.

If the bearings are good in you cush drive put a fairly big run of silcone in the mating faces of the cush drive rubbers, assemble the rear wheel and let it sit overnight to let silicone cure.

It is a fairly common treatment on large hydraulic motor couplings ect on mining gear and have always had good results, no play = no wear= lasts for very long time. Bearings must be good though.


regards
jon

ive changed the sprocket carier bearing, and that has solved the problem the brearing pretty much fell apart when i took the cush drive off, i wish the people who have there bike before i buy them would try and look after them properly, lol.