Non-starter

Its easier than that, get a 16 thou drill (also known as a #78) and mount it in a WD40 red tube using epoxy glue. Remove the pilot mixture adjusting screw and then insert the drill and twist the red tube using your fingers, when you are finished use carb cleaner areosol to get rid of any loose crud, replace pilot mixture screw and then unscrew 1.5 Turns. Once the engine is started and up to temp tune the pilot circuit.

Are you sure it hasnt wet sumped, and oil drag is stopping it from starting?

Drain the sump, are the plugs wet with fuel ?,if dry introduce a squirt of fuel into the carbs or plug holes, if it fires up then stops and won't restart then its likely you have a fueling issue.

Plug leads not crossed over?

My local car bits agent sells a spray tin of Ether based engine start goo called Quick Start. You just aim it inside the carb mouths and pull the trigger for a few seconds. A few turns of the engine to suck it in and then the big swing. If my engine does not fire up or at least kick back then I know either the battery is low or there is another electrical problem somewhere. Quite often it is manky terminals to the coils or earthing wires. On my Dommie recently, the lack of go was caused by the points gap narrowing too much.

After being laid up my 71 fastback is always a B to start. I get the plugs scagging hot in the kitchen gas ring, usually goes after a couple of kicks then.

New plugs, Yes. Even after many years of classic bike fun I make this mistake and assume i can clean plugs. Must be something different with the fuel. I use BP ultimate in several bikes and they all run richer on this. Cleaner running on Std ethanol but cant risk the damage.

I would remove the plugs and syringe about 5cc of perol into the plug holes with the pistons at TDC, replace the plugs, caps etc, ignition on an give it a good kick. It should fire if only briefly. Then you know if you are dealing with a fuel issue or ignition (if it doesn't fire)

The change from SAE 40 to 20/50 multi did it for me in my Commando.. Now with a good battery it is a first kick start even after 2 weeks standing!

Hello Roger,I think the artical you

mention is the one called BUSHMANS CARB TUNING SECRETS by

Jim Bush jim@jba.bc.ca I found it to be very good.

cheers,Mel.

Previously roger_johnson wrote:

I am re-starting work on my 850 having gone through the electrics. I have checked the timing staticallly, have new fuel, and a good spark with 12V plus at the new coils but it will not fire up. It does not even cough ;like it would like to go so I am assuming no fuel to the combustion chamber. I had a reply from someone a while back who suggested I can make sure the drillings in the carbs are not blocked by drilling right through the carb [carefully!] and then cleaning with a pull through [I think] then fitting a blanking screw. However I did not save this piece of advice. Can any one else help here?

Many thanks Roger

You don't say if you're still on original contact points ignition or electronic . Have you tried swapping over the HT plug leads?With the original contact points ignition set up it's quite easy to get the wiring on the points accidentally swapped over during a rebuild resulting inthe sparks happening 180 degrees out of phase , ie on exhaust stroke rather than compression stroke.

Just a thought....

You said you have 12v at the new coils. Did you fit new 12v or 6v coils?

They should be 6v coils. I have seen this before. A good spark in free air but poor spark under compression.

Paul

Previously roger_johnson wrote:

I am re-starting work on my 850 having gone through the electrics. I have checked the timing staticallly, have new fuel, and a good spark with 12V plus at the new coils but it will not fire up. It does not even cough ;like it would like to go so I am assuming no fuel to the combustion chamber. I had a reply from someone a while back who suggested I can make sure the drillings in the carbs are not blocked by drilling right through the carb [carefully!] and then cleaning with a pull through [I think] then fitting a blanking screw. However I did not save this piece of advice. Can any one else help here?

Many thanks Roger