Swap plugs to start

Find some really old ,old plugs give them a clean and try them,modern plugs are not designed for oily old clunkers!.

Previously robert_tuck wrote:

Find some really old ,old plugs give them a clean and try them,modern plugs are not designed for oily old clunkers!.

Really? Why then did you advise, a few hours ago, on another thread, that it is not worth cleaning an old plug?

Its not worth cleaning an old MODERN plug as its insulator is porous, an old OLD plug is something different as it has a glazed insulator which is non porous and will clean. Find some really old plugs and put them in a safe place ,you may need them someday.

After years of difficult starting using NGK plugs I read a piece on the Green Plug company's web site that stated that the modern insulaters are porous and don't like to be flooded with petrol.

I sent off for some pink Lodge plugs ( apparently race plugs) and the bikes now start remarkably easily.

Back in the sixties, we always had warmup plugs for our methanol burning J.A.P, ESO and Jawa engines. If I remember correctly, it was something like Bosch 225 and then 460 for racing.

And if they are Chinese knock off NGK's they will fail PDQ.

If your plugs are black all over the insulators they will be tracking - hence not starting. Sounds like you are running too rich. Nothing an electrical current like better than a low resistance carbon path to follow rather than jumping across an air gap. You really shouldn't need different plugs to start and warm up unless you are running exotic fuels.