Topic: Cb750a Issue HELP

[1977cb750A]

Hey everybody

I am having an issue on my 77 CB750a. I can ride it about a mile to a mile and a half before it drop from 60mph to 40mph and die or sometimes it will keep going 30mph for a mile or two then it dies. Awhile after it dies it will start and do the same thing again a mile down the road. We found an issue with the reglator and fixed it its charging now 13v. We replaced the sparks plugs and cleaned the fuel bowls. It did the samething again today 60mph to 40mph and then it died and would not restart because the battery died from cranking it so much. I read a couple of other peoples posts about simular issues. The fuel cap hole is cleaned and the pet---- is also clean letting fuel pass through.

Needless to say I'm tired of pushing it home so anything that would help is greatly appreciated.

[05c50]

First you'll need to decide if it's a fuel delivery problem or an ignition problem. If it were me, I'd go for a ride with some tools in hand. When it quits open a carb bowl drain screw to see if there is fuel in the bowl. Then plug in a spark tester and see if there is spark at the plugs. Now that I think about it, you might want to do it in the reverse order, you don't want an ignition source on the gas that you just drained.

.....Paul

[PeWe]

Maybe ventilation in tank that is clogged by rust?
Try to ride with cap open very carefully to avoid fuel tsunami.
Or petcock clogged, the filter make fuel delivery very slow.

[1977cb750A]

I think its more of a fuel issue with the tank. We had some bad premium lots of water (its drained on the side of the road) so i guess ill have to clean out the whole tank maybe replace the pet----

[Randy Nevrotski]

try starting fluid . when it shuts off spray some to see if it starts . BE CAREFULL . if it starts up then fuel problem . then open each bowl to check for gas if all full the carbs have to come off and clean . if u have to take carbs off make you pull all 4 slow jets and press them back in all the way.