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[2codpete]

I noticed that the head gasket is leaking would that cause the backfiring.

[vince]

Hi, with the brake cable passing through the casquette it can chafe against the ammeter connections causing shorting.Vince PS check the plug gap, at high revs it may faul to spark.

[2codpete]

Hi Vince checked brake cable on ammeter all good,gap plug still no good any other suggestions.cheers

[Andy C]

Pete. Reading through the thread it looks like you have replaced / fitted new: Spark Plug, Coil, Capacitor, Battery & Carb - is that the case? Valve clearances aside these are the usual suspects for a miss fire. What sort of HT lead do you have, is it a wire cored one or an supressor plug lead? if the latter try replacing it with a wire lead, also what sort of plug cap? if it is a supressed one, replace it with a non supressed one. Supressed plug leads and caps are know to give problems. Failing that it would be worth pulling the carb off and give the jets and airways good blow through with compressed air - is the carb brand new or new / used? if the latter then the jets / airways could be blocked - even brand new carbs sometimes have blocked airways. Just a few thoughts.

[Aethelric]

I think "the ammeter goes crazy at times" points to an electrical problem somewhere. Either an intermittent short circuit caused by a chaffed wire somewhere or an intermittent open circuit caused by a loose or corroded connector.

Not unusual in a 35ish year old bike

[2codpete]

Hi Andy C I have orded a new coil I think the one I have maybe suspect.does a wire core ht lead have about 8 wires through it? that's what I have carbie is new but I will take your advice and give it a good clean.cheers

[2codpete]

Thanks Aethelric I will have go and check all the connections.cheers

[Andy C]

Pete - you have a wire cored HT lead then, so should not be a problem - dont forget the plug cap, if it is a supressed one it may be causing the problem so I would replace it with a non suprssed one.

[2codpete]

I have a new problem while checking the ammeter wires I left the bike turned on for about ten minutes and it cooked the coil.it shouldn't do that any suggestions on that anyone.cheers

[2codpete]

Thanks everyone for all your help bike is all sorted now and running sweet.cheers pete