ca77 misfire under load at high rpm.

[win1906]

my 67 dream misfires under load at higher rpm.it starts and runs good at idle and revs up fine.but going down the road it misses at higher rpm.it will start doing it in 3rd and stop when i shift into fourth.and start doing it again when the rpm gets higher.i have set the timing and replaced the coil with another one,still does it.i am going to double check the points gap valve gap and cam chain adjustment again when it cools down.i am thinking its a ignition problem and not a carb problem but i dont know.any suggestions i would be willing to try.thanks guys.

[Rizingson]

Replace or at the very least clean your points. Its the most common problem with underload missing at higher rpm's. Of course reset the gap per spec.

[Billiam]

I'm in the same boat Win1906. She even started while I was finding compression with the kickstart. Warms up quick. Ticks over like a watch. Revs out a treat untiil like yours you put the hammer down then she starts cutting and lurching. Stop for a few moments at the lights and shes ok again till you load it up. Done all the carb/ignition timing/points etc. even raised the needles a notch. Plugs look the same - clean slightly pinkish. So frustrating.
Might try a set of pattern coils as a way of elimination.
Where can I buy new points in UK. Don't say David Silver, none listed.

[DCheney]

Once I hit the tiger register, it starts bogging and putting out... I can feather the throttle to keep it rising, but this issue is killing me. Can anyone help?!?!? An old-timer told me to check my mufflers, said a mud robber nest could cause such an issue... Thoughts, or has anyone fixed their issues...?

[e3steve]

Just been trawling this thread. Three things immediately spring to mind, in the following order:

1. Condenser
2. Lean mixture at WOT
3. Valve clearances