1977 CB550 fuel not flowing into carbs

cyclemanbill

Hi guys, I just removed, cleaned and reinstalled the carbs on my 550. They were not too bad, but 2 of the needle's (#1&#2) were stuck shut. Anyway got everything clean and working to my satisfaction, then put it back together, only to find that #2 carb, won't accept fuel. I put some air pressure to the fuel line going into carb but no luck.
Any ideas out there that might solve my problem short of pulling it all apart again.

Thanks............Bill

JimMc · Posted: Tue Jan 17, 2012 5:53 pm Post subject:

Try tapping float bowl lightly with a plastic mallet.

cyclemanbill · Posted: Tue Jan 17, 2012 6:55 pm Post subject:

Thanks Jim, I already tried the tap, tap, method, nutin doin.
I just went out and removed the floatbowl from #2 and the needle & seat are working fine, but when I install the floatbowl the valve closes. Looks like I got some upside down float adjusting to do.

cyclemanbill · Posted: Tue Jan 17, 2012 7:24 pm Post subject:

One reason people hate to ask questions is because sometimes it lets poeple know how stupid they are. I think I have mounted my floats upside down......

05c50 · Posted: Tue Jan 17, 2012 8:09 pm Post subject:

Ahhh, don't beat yourself up too bad. it's been done before. Smile

It might have happened in my shop a few times. Wink

.......Paul

cyclemanbill · Posted: Wed Jan 18, 2012 9:37 pm Post subject:

Hey, I was able to remove all of the float bowls and turn of the floats over, not easy but doable.
Engine started right up and sounds fine.
However....after reving the engine, the rpm hangs around 3 grand for about 30 sec, before dropping to idle speed. I'm thinkin lean, but I have never tuned more than 1 cylinder, so I need some direction. Anybody wanna help this ole boy..............Thanks......Bill

HebrewHammer · Posted: Sun Jan 22, 2012 8:18 am Post subject:

I know this sounds stupid, but as stated previously, we've all done stupid things. Did you check to see that the throttle is releasing when you let go of the grip? Maybe a pinched, or sticking cable, return spring, etc.? If that's not the case, I'd go with rich over lean. Lean would cause it to just die from lack of combustion, high revving would be more from a lot of fuel being left over in the cylinder to be burned off. Does it diesel (keep running) after you hit the kill switch, even for a few seconds? If it does, you're rich, if not, you could still be rich, but maybe not as much, and might have some more issues than just fuel mixture. Let us know.

05c50 · Posted: Sun Jan 22, 2012 1:23 pm Post subject:

I agree.....kinda. First check that the cable is allowing the throttle to close, then I would check for a vacuum leak around the carb to manifold insulators, and then I would check the carb sync. I've seen more than a few 4 cylinder bikes that suffered from a hanging idle that were repaired by properly syncing the carbs.

..............Paul

cyclemanbill · Posted: Sun Jan 22, 2012 5:26 pm Post subject:

Thanks for the ideas.
Throttle cable is not binding. I have sprayed WD40 around the intake boots and found no leaks.
One thing I have noticed is what appears to be a very loose timing chain that I have not figured out how to adjust. The owners handbook that came with the bike says to adjust the timing with the engine @ TDC.......I've tried both TDC's (1-4 & 2-3) by loosening & then tightening the nut and am having no luck. Don't know if this could be related to my problem, but its gotta be fixed.

05c50 · Posted: Sun Jan 22, 2012 5:40 pm Post subject:

Adjusting the timing chain and adjusting the timing are two different things. Which one is giving you trouble?

..........Paul

cyclemanbill · Posted: Sun Jan 22, 2012 7:39 pm Post subject:

It sounds like the timing chain (valve timing) is slapping the case.

cyclemanbill · Posted: Mon Jan 23, 2012 4:03 pm Post subject:

Thanks again for the great advise.
I started the engine and noticed that #4 exaust header was cooler than the others, so I leaned it a little and shazam, it now idles just fine. Take er for a ride and sure enough the idle is dropping like it should. I'm startin to love this bike, BUT when up to my garage it lost all electrical power.
I'm going to start another thread relating to this problem.