Sparks

If the ignition had a wasted spark (IE: once every 360 deg instead of 720) the engine would run perfectly whatever way you connected the leads...

When an engine refuses to start and there is a good spark, I remove the plug/s and pour in about a teaspoon of petrol directly into the cylinder...kick the bike over once or twice refit the plugs and attempt to start it. Usually the engine will fire like this and if you are lucky might continue if the carbs have fuel in them if the engine stops again in a second or two it is almost certainly the fuel supply and you will have to go through the process to hunt down why the fuel is absent....have you tickled the carbs to make sure petrol is able to fill the carbs?...this will eliminate several possibilities straight away.

Les

Previous owner said... famous last words. Have you checked the static timing? Also if you have points or electronic type ignition, the latter is usually wasted spark.

Have not got it timed on the wrong timing mark on the rotor maybe?

Check it is firing just before TDC

If you are on points, there is not a wasted spark.

Previously gary_knowles wrote:

Have not got it timed on the wrong timing mark on the rotor maybe?

Check it is firing just before TDC

If you are on points, there is not a wasted spark.

I agree, if everything else checks out I would check that it is not timed on the wrong mark on the alternator rotor. Some have two marks but only one is right, if you choose the wrong one to set your timing by it will 180 degrees out, I know 'cause I've done it myself,

Regards,

Pete Austin

I know this is an odd thing to ask but have you put in new petrol as this rubbish petrol we now get goes stale and the engines are a pain to start. I have found if it is left for too long then these engines can be a pain to start after being left standing. Also have you a fully charged battery? You can squirt some petrol down a plug hole to see if you can get it to at least fire up for a while, as this may be all that it needs to run.

I had the same problem. Checked everything, so I thought. Finally tracked the problem down to non-ethanol-proof fuel taps. When turned on they appeared to be letting fuel flow through but it wasn't actually enough to keep the float bowls full, even with both taps on. The carbs tickled up fine so there was no clue there. I even ran a drill through (taps open and out of the tank) to make sure they were clear. However, the non-proof seals simply expanded again to partially occlude the openings.

Put new ethanol-proof taps in and off it all went!

I agree with Pete Austin above, by the way, as I too have timed the engine on the wrong alternator rotor mark before. I deal with that problem these days by marking the rotor with a centre punch next to the correct line when the barrels are off during the restoration process - ensuring that the cam spindle is in the correct position.

Phil

I can't say it enough times, stay away from EN228 containing 5% ethanol.

At a show last weekend, a gentleman tried to start his 500cc Ve**0. He brought the bike in a van but had not started the bike for over a month when he used Jet petrol.

No way was that bike going to start and goodness knows what state that carb was in too?

Esso Supreme Synergy 97 octane in the UK, except for Devon and Cornwall, Teesside and Scotland is guaranteed E0. Why people insist on putting Green rubbish in their tanks to not only have all of the associated problems but also to have a lower mpg, I'll never know.

E0 petrol is still good well over a year and more later!

Sorry no magic solutionfrom me, iirc you need electrickery, fuel, & air to get the bang. if one is missing she just won't go.

What could be wrong will depend upon your setup, have you got any life at all or just stone dead, do you have a boyer (battery recent?), I assume a pair of Amals from your comments, is the fuel getting through to the sparky bit? Are the carb inlet flanges leaking, etc.etc.

I spent a day in Spain trying to work out why my Commando was only running on one cylinder - it turned out that the throttle slide cable had pulled out of the crappyplastic Amalcable splitter so only one carb responded to the throttle. So there's always a new take on the old problem.

Let us know how you get on!

Mike

I had difficulty starting mine a while back and discovered that twisting the twist grip about an eighth of a turn at the same time as kicking it over got it fired up.