Slight misfire problem?

[jwitty]

So I noticed that the b has a slight misfire when just putting around or especially going down hill. A lot of times it'll start missing when it's going down a hill then start firing again. When under load it hits strong and every time with no miss. Could it be just a plug? I've replaced plugs, wires, points, condenser, and right now running off an automotive coil instead of mag because I was having hard starting with mag. And it misses no matter which way the idle needle is set on carb (Its around 1 3/4 out rn) so I'm assuming its ignition problem.

 

[Lee B]

I'll suggest your assumption is wrong. These are well known to have mixture problems what with the 180 - 540 degree span in intake surges thru the carburetor which is why they finally went with a two throat design for the carburetor in an attempt to rid them of the ghost miss you speak of. It's there, but it's barely there and goes away under heavy load entirely.

 

[jwitty]

Well I took both plugs out, one had just a little bit of black, nothing horrible. The other one was just covered in carbon and crap. Took cap off and one lug (the one on the bad plug) is extreamly worn compared to other side. Must need a new cap

 

[ET]

Does it push blue smoke out the exhaust when you are going down the hill and it starts to
misfires? You may have some bad rings and you are oil fouling on the coast but it cleans
out when the engine goes back to work.

 

[jwitty]

(quoted from post at 19:15:02 11/23/17) Does it push blue smoke out the exhaust when you are going down the hill and it starts to
misfires? You may have some bad rings and you are oil fouling on the coast but it cleans
out when the engine goes back to work.

Not really. It burns a little oil when cold but when warm usually it's just black if anything. Like I said the cap is in pretty rough shape. I don't think anything major is wrong with engine because oil has stayed full and has plenty of compression and power.