Carb question engine stays revving

[Indy1K]

I cleaned up the carbs on my 82. Front one still not working right cause accelerator pump not shooting and cylinder is cold. Cleaned up another front carb and replaced it. Now front cylinder hot and acc pump working, but when you hit the throttle, it doesnt drop off the rev quickly. Infact, it stays up a long time, then trails off. Also idling unevenly.
I have repaired the YICS unit too. Almost sounds like a vacuum leak, but where.
Both carbs have been cleaned, will order rebuild kits today.
Fuel pump rebuilt
New Plugs, oil, filter, air filter,
Could it be faulty fuel pressure recirculation valve causing too higher pressure?

Any ideas?

Thanks,
Kevin

[inanecathode]

Too high fuel pressure will burble it out, dont worry about that.
I'd get it idling and get your carb cleaner with the straw and spray around the carb boots, vacuum fittings, etc, finding that vacuum leak. The only reason revs will ever stick on this particular system is if the cylinders are getting air when they're not supposed to. This could be a few things:
Vacuum leak
Idle set too high (you've got the idle set really high to accommodate crappy carbs so now that they're clean it'll go nuts)
Carbs waaaaay out of sync

The first you find with some kind of solvent spray, the second is you just reset the idle, the third is you get/make a sync tool or start out with a base sync of closed throttle plates. First thing i would do is take off the yics box and plug the ports and see if it gets any better.

[Rikugun]

There's a weight and check ball under the accel nozzle that might be stuck on the first carb you tried.

I agree it sounds like it may be a vacuum leak and would try inanecathode's suggestions.  If you question the pump at all, take it out of the equation during diagnostic tests - it may be the source of a vacuum leak. Disconnect it's vacuum feed and the regulator's and plug them off at the engine and carb respectively. You can run the bike on a test tank (hung above the carb height) connected to the "T" that feeds both carbs. Sometimes I'll just use the body of a plastic turkey baster (shoved into the rubber line of the T) as an impromptu funnel. It holds about 50cc and works well for short tests. Keep an eye on the fuel level in the baster and refill from a ratio-rite cup (or suitable easy pour container) as needed.

Carb synchronization can take some time (especially if you're adjusting the mixture screws as part of the process) so I wouldn't reccommend the baster for that. It will have you refilling the "funnel" often and it gets to be a hassle. If you don't have a test tank, just install the bike's tank and use it. This of course assumes the pump has checked out ok and you've reconnected the various hoses. Since the sync tool will connect to the front cylinder small vacuum fitting that feeds the petcock, use the Prime position for the test.

[QBS]

Kevin, to answer your question: No.

You did not mention resynching the carbs after changing out the front unit.  If you didn't resynch the carbs, then that is quite likely your problem.

[Indy1K]

 :o thanks guys, lots of good information.
I am good with a test tank. I use a rear end lube bottle with a hole cut in the bottom, taped to the left mirror and the nozzle in a long piece of hose to the pump. Blocking the vac line on petcock.
No, I havent synced yet. Anyone have plans for a carb sync tool?
I also will check for the vacuum leak with carb cleaner and thake the pump out of the circuit.
Thanks for the help, ;D
Kev

[The Prophet of Doom]

Off Lucky's site

[Indy1K]

Thanks Much!!!

[inanecathode]

When you're using the hose-on-a-stick technique, use a pair of pliers and clamp them over the two hoses crossed over eachother like an X, otherwise the fluid bounces around so much it's hard to see, it froths, or it just gets sucked into the motor and burned.

[Indy1K]

I was thinking of using the fishtank valves on the stick design ???

[inanecathode]

I was thinking of using the fishtank valves on the stick design ???

That'd work.