Would This Cause

[GLscoot]

Finished my build and done a couple of laps around my housing estate without any problems. Then it cut out, checked woodruff key and it had sheered off, replaced it and starts then dies, checked throttle cable and it was a bit slack, while tightening the throttle cable noticed one of my headlight wires may have cut through to the copper strands, would this cause it to short out & not run properly. Im hoping this is the case as the woodruff key made a mess of the flywheel and crank shaft. It was the throttle cable guide that cut through the plastic coating on the wire.
I ran out of patience to change the wire, so checking on here before I start again tomorrow.

[coaster]

The lighting coils and ignition coils on the stator are not electrically connected so I don't see why a short on the lighting would cause your problem

[GLscoot]

bollox, will need to investigate more tomorrow. cheers for the reply anyway. beginning to think a seize has caused the woodruff key to shear or a snapped ring. it does start but cuts out immediately.

[coaster]

Do an ohms check on the ignition and pick up coils before you pull it apart, check the continuity of your earths too

[Yanker]

The lighting coils and ignition coils on the stator are not electrically connected so I don't see why a short on the lighting would cause your problem

Well they do very effectively 'connect' on battery ignition Vespa GS for instance, and lighting impedence also affects ignition on lame 4 pole ignitions with a wide plug gap.....

Obviously a bit more information would be helpful here......A sheered woodruff key has most likley damaged one or more of your ignition circuit componrnts (whatevertheyare) is my quickie.

[GLscoot]

I suppose I have been pretty vague, will do the continuity test and see what happens. Just got fcked off as it was running fine, tightened all the cables fitted all the digital speedo shyte, panels etc. etc. and then nothing. Had to walk away before I did something stupid. Was hoping for confirmation on the wiring front.

Its a reed valve engine in a GS150 frame with the Pinasco Flytech Ignition System, the same as the Vespatronic wiring with the two pin CDI box, Im pretty sure everything is connected in one way or another electrical wise. Im not running a battery.

[GLscoot]

Having checked the barrel for damage, nothing. Continuity test all good. Flywheel torqued down all good tried to start it and again nothing, checked for spark, good spark. Checked fuel, plenty of fuel. Decided to change plug to one from a running scooter and first kick off it went. So I don't know if the plug got damaged when the woodruff key sheared off, but I was getting a spark from it. So at the moment all is good, test run next.

[tonydevon]

NGK plug? maybe cheapy from Eblag?

see it quite a lot as all my bikes run 4 or 8 plugs I have seen them spark fine but bikes refuse to start, under compression the spark is just put out and nothing happens

bought from a local bike shop and perfect

[GLscoot]

yip, bought a box of 10. Im going to check the writing on the plug, as I left the shed I noticed it looked odd.

[tonydevon]

fakes in my opinion, check the boxes, they slightly different colour.