Re: yet another jetting question

> > This '81 CB650 has something to teach me. (the positive way of looking at
> > it)
> > 
> > I got it at the beginning of the summer with 13,000 mi. I just checked the
> > odometer, I put a little more miles on it over the summer than I thought.
> > It's at 18,000 now.
> > 
> > At first it would cut out if I gave it more than 1/4 throttle, under load.
> > Going up a hill on the freeway required that I let up on the throttle so
> > it would have enough power. Downshifting just made it worse. It seemed
> > like it didn't want to rev, but as long as I built speed while the
> > throttle was barely open, it would eventually get past 5,000 rpm.
> 
> Does your CB650 have CV carburetors? Am guessing that it does and that one
> or more of the vacuum diaphragms has a hole in it. Or if it uses the
> piston style CV carburetor that one or more is sticking.

That sounds like something to look into. (in addition to all the other
tips from the group) I don't know what the style of carb is called,
but I know there are no diaphragms, except the accelerator pump
diaphragm. There is a piston with a needle attached that is vacuum
actuated. Now that I have the bike working reasonably well, I notice
that acceleration is jerky, unless I go balls out. It seems like the
pistons might be sticking. Can I polish them, and polish the bores? It
seems like that might help. It seems like trying to lube them would be
a bad idea.

Thanks to all the people that responded to my questions. It's a big
help.