Vacuum tube? and Carb problems?

[Big Dave 79]

Hello my fellow NC30 nuts

Once again its that time of the year...and I dont mean Christmas

The NC30 wouldn't start...no power, checked it by jump starting of the car - no go

Got a new battery today all fitted fired it up - All ok choke on no throtle - The bike ticked over all ok then - DEAD.

Checked battery and all is ok (brand new)
Checked air filter all ok (a bit mucky time for a new one, but its ok for now)
Checked spark all ok (so that rules out the kill switch)

Two options left i think:

1) Old fuel in the Carb, looks like a misson to do so not the first option and from what I understand it should fire anyway but not 100% efficent, plus does anyone have a dummy guide to removing the card? also can I bleed them without taking them off? If yes were is the bleeder? Any specialist kit need before I undertake this monster?


2) The tube on the tank (the vacuum tube i think) where does it go? (the end not connected to the tank i mean) Is it possible that there is too much air getting into the system through this?

Any help would be appreciated as usual

Thanks and Happy Christmas or Nadolig Llawen (if your from my part of the world)

Dave

[royster81]

2) The tube on the tank (the vacuum tube i think) where does it go? (the end not connected to the tank i mean) Is it possible that there is too much air getting into the system through this?

which tube do you mean,if it's the one from the top of the tank thats fixed to a breather that screw onto the tank,for now just make sure thats not blocked, check the fuel tap if you have had the tank off, the tap should have two hoses going on to it,one for the fuel and one for the vacuum hose to attach to,if the vaccum isn't attached not matter what you try it's not getting fuel to start

when was the last time it started and whats been done since then ?

[Big Dave 79]

Thanks for the reply, the fuel tap only has one tube off it. from the fuel tap to a T splitter.

Im sure the previous owner used this for track racing and by the screwdriver marks on it it looks like he's done a fuel tap HRC mod.

The bike has worked fine in the past and this year i've ridden it 1000 miles plus with no problems until now.

It has been standing for 3 months and I fired it up 3 weeks ago and then it fired up today fine for about 5 minutes

Any other ideas or info?

[royster81]

Im sure the previous owner used this for track racing and by the screwdriver marks on it it looks like he's done a fuel tap HRC mod.

be sure if he has or not and if he has reverse it asap,check your oil incase the petrol has leaked into the sump,very common in bikes with the tap mod done that sit for a long period of time

[Big Dave 79]

not the easiest thing to check, but im guessing that the fuel tap only having one line from it shows that it has been done, the bike has run fine like this? what is the reason for changing this now? as the only way to fix this is to get a new fuel tap?

[Jon]

If you can remeber to turn the fuel tap off every time you park the bike the HRC tap mod shouldn't give you running trouble but I agree with Rorhy I would chenge it back.
My bike had it done when i got it and i put another tap on the second time it dumped all its fuel into the sump.

The breather hose from the tank doesn't connect to anything on the other end.

They are very prone to fouling the plugs with fuel, I try to avoid starting mine and truning it off without warming it up.

If the plugs are fouled I have had some success by pulling them out and drying them on a gas ring on the stove.

regards
jon

[Big Dave 79]

Ok thanks guys, I think the easiest thing to do is look out for another fuel tap.

I checked the plugs (well the two that are accessable under the tank) yesterday they are black and well oiled time for some new plugs also?

If the fuel is going into the sump I guess that means a oil change is also in order?

I think im going to go for the carb removal as the fuel in the tank is at least 6 months old if not older, any hints or tips on removing the throttle and choke linkage?

Thks

BD79

[Sligeach]

if you do go taking the carbs off just to let you know its an acquired skill to get them back on.
it took me about 6 times on and off before i mastered the trick.
make sure you loosen all the clamps on the carb rubbers and gently pry the rear carbs off the intakes first, also label all the pipes too.
both the throttle and return cables need to be taken off, a 10mm spanner IIRC

[royster81]

the carb bracket is held on with two screws onto the carb,if you take these out the whole body comes off with the cables attached and un adjusted ,this way when you refit them you don't have to adjust them