so, after a year and 3 month project, the nc23 is finally in a position to be started. Filled her up with all fluids and a good charge and turn her over in anticipation....NOTHING.

After rectifying a few problems:-

Blocked carbs (now clean)
Fuel pump works
HT leads fine
Fuel cut off relay working
spark plugs replaced (and sparking)
Coils checked
earthing correctly everywhere (additional earth wire)
complete wire loom check
pulse generator risistance checked
regulator rectifier checked

You name it Ive probably done it...can't remember anything else...

at present there is now air box attached (so just carbs) and now exhaust (just down pipes) will this affect starting?

When I try to start it, it back fires all over the place, and through the top of all four carbs. all four down pipes are hot, fuel is definately getting through, definately sparking! even tried easy start down the carbs...no luck!

Any suggestion guys please, I'm running out of ideas!

Firing order may be wrong .... or valve clearances way off.

Check plug leads are on the correct cylinders ...... as are the trigger wires on the coils .... and check the valve clearances.

Firing order checked and double checked, all leads to correct cylinders (1-4) left to right when sat on the bike.

Havn't checked valve clearances....but will do later on. The engine has been sat for a year and 3 months, but only the side casings and rocker cover taken off, no engine internal work has taken place.

Thanks for your reply! will let you know how I get on!

When the carbs are on the bike are they filling with fuel? Just turn one of the drain screws to see.

RyanNC23 wrote:Firing order checked and double checked, all leads to correct cylinders (1-4) left to right when sat on the bike.

Havn't checked valve clearances....but will do later on. The engine has been sat for a year and 3 months, but only the side casings and rocker cover taken off, no engine internal work has taken place.

Thanks for your reply! will let you know how I get on!

How have you got your firing order?
should be 1-4-3-2 left to right of the coils

Choke cable not working?

Tickover set too low?

I started mine last week with a can WD-40 sprayed the mist over the carb inlets when cranking, the fuel pump was empty and so was the float bowls, was playing around a few weeks ago with the tank off. Left it sitting in the garage too long. Just got it going enough to get the fuel thru.

I thought it was never going to go again.

Carbs are definately filling with fuel,

Thanks for the help guys!

firing order is set up as 1-4-3-2

choke cable isn't attached, ive been manually opening the choke

tickover set been set on all sorts of levels from fully closed to fully open

Ive also tried easy start over the carbs, so I'd assume that would be the same as your WD-40 trick.

It feels like this will never start again, which sucks especially after all the time, effort and money plowed in to restoring her!

Also, before I check valve clearances, is it likely to be this? as I havn't touched engine internals, and the bike ran well before I stripped it down?

Good news!

after checking the coils for a 6th ish time, realised that the blue/yellow & yellow/blue wire were on the wrong coils, swapped them and she starts!

Downside is it's now revving like mad?

tickover is right down and choke is down too...any suggestions?

RyanNC23 wrote:Good news!

after checking the coils for a 6th ish time, realised that the blue/yellow & yellow/blue wire were on the wrong coils, swapped them and she starts!

Downside is it's now revving like mad?

tickover is right down and choke is down too...any suggestions?

You got your throttle cables on the right way?
Mixture screws at the right setting?
Carbs balanced?
idle screw too high?

no throttle cable attached, it just starts and revs to redline!

what should the mixture screws be set too, ill double check them, the haynes manual has no data, is it 2 1/2 turns Ive heard somewhere else?

it ran fine before I cleaned the jets out, so would carb balancing really be an issue?

idle screw set to minimum!

ill pull the carbs out tomorrow and have a look at the mixture screws.

I'll let you know how I get on...Cheers