hi there can any body point me in the right direction , my honda back fires mostly at high revs it seems to stop if i rev it out. it is points ignition. i dont know were to start as it used to run perfectly . i think i have every thing set correctly could it be the advance retard mec perhaps? where should i start fuel or ignition?

I would drain carb, and change the plug.

After that try another coil if you can borrow one.

I would drain carb, and change the plug.

After that try another coil if you can borrow one.

hello . the carb is clean i have a coil of another bike of roughly the same era i could try maybe . i did replace the condensor about a year and a half ago but ive only done about 4 trials on it i think i will try a new set of points as well and then see ,the plug by the way was a perfect color when i took it out so i am still wondering

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worth checking that the pivot points for the points and advance retard are greased.

Edited May 20, 201016 yr by B40RT

set points to 12 thou,check timing