Bike missing at high speed

[64honda]

Hi Folks,
Been reading up on the forum here and decided to join and ask for help! I've got a 64 CA77 Dream. The engine hadn't run for years, but has low mileage so i decided to not tear it totally down. My problem is that the bike seems to idle and run fine, except at 60mph or above! It spits, cracks, misses like crazy and loses power until i get the speed back below 60 and it runs like a sewing machine again.

All bottom end oil seals have been replaced, the carb has been rebuilt using stock jets and the float height is 26.5mm. Carb spacer o-rings were replaced, i did the static timing trick with the 12 volt light, alligator clips and the ol' "F" mark. the plugs are a nice light brown and i've put about 400 miles on the bike. i put new condensor and points in and have adjusted them every 100 miles and cleaned them using 600-400 grit then finished up with a business card and some electrical spray. i'm running the original coil and wires with of course new NGK plugs. the bike starts on the first kick every time. i didn't even notice the problem until recently because i'm always riding on the blue ridge parkway (speed limit 45).

i'm starting to wonder if the advancer springs or something may be weak. Any other ideas from anyone? Thanks for reading!

[briarpatch]

64honda - Where are you located? I'm near Linville on the Parkway. If you're not too far away we can get together and figure it out ( I have some diagnostic stuff). I'm taking two CL77s and making one good one. THANKS - Stan

[dlobby12]

Did you ever figure out why your bike was missing at high speeds. I'm having the same issues and it's got me stumped.

[davomoto]

Sounds like they may be running out of gas. High gear and load. Good fuel flow form the petcock< Screens removed form banjo fitting?

Davo

[head]

Have you checked the coils, spark plug wires for good contact, spark plug caps, timing, cam chain adjustment, points, timing. Carb bodies clean on the inside?
That's how I go about it. Have my 67 cl77 305 for 42 years now.
Head

[LOUD MOUSE]

His one and only message was June 2 and no responses to the replies.
Waste of time!. ..............lm

Have you checked the coils, spark plug wires for good contact, spark plug caps, timing, cam chain adjustment, points, timing. Carb bodies clean on the inside?
That's how I go about it. Have my 67 cl77 305 for 42 years now.
Head

[dlobby12]

Yea did all the tune up requirements according to Ed,
but it was none of that.
I had put an after market petcock on that had an internal screen.
Took it out and that solved the problem I'm going to add a inline filter.
that should do it. thanks for the help.
I try to reply to everyone I think sometimes they don;t go through
don't mean to waste any ones time you've all been so helpful.
Thanks again