can you guys help me with a old CB350

[cbrophy22]

1973 CB350G front disk. twin
Ok here the problem the bike starts up and idles fine. but if i rev it up to lets say 3 grand it will stay at 3 grand. and if I take it to red line, it will rev up and then go down to about 5 grand?? I shut the bike off and start it up again and it idles fine at 1200. any thoughts thanks

[Nessism]

Sounds like an air leak or stuck throttle/slides.

[seuadr]

yep, i'd clean the carbs real well and then check for air leaks if it persists.

[buster]

I have had a couple of CB's (oldest being 73 CB440) and the cables are crap and like to stick and you have to clean up the slides real well also. I have had to soak just to get them out.

[onchiman]

I just rebuilt the carbs on a friends '73 CL350 last week. Had sat for a year and both vacuum sliders were stuck. Those carbs are easy to work on but have tiny o-rings on the jets which are pressed in and retained by a clip type holder that presses against the bottom of the float bowl when the bowl is tightened on. There's also an o-ring on the needle valve seat which too is a press fit. Those o-rings should all be replaced. To get at the low speed jet you have to remove a rubber plug on the jet tower and unscrew with a small screwdriver. Be careful with the aftermarket carb kits as they sometimes have the wrong jet sizes. It's best to re-use your originals if they're in good shape.