Unable to balance carbs

[Gil1696]

I'm having probs trying to balance my carbs. The balance adjustment screw seems to have no effect (I hope it's the balance screw, next to the idle adjustment screw.)
In addition, I can't get the bike to idle correctly. It'll either idle 3000 revs plus or not at all. Regardless of weather, Or fuel type, or giving it a hand full when stationary.
The bike is one of the early models (No.617) and at only 8000 miles when I bought her, I guess that she'd been stood idle for some time previously. The bikes never really idled all that well. But general running has deteriorated of late.
Could the butterflies be gummed?
Could the jets do with a clean?
Replaced Choke, open and close cables of late and lubed them well (no sticking apparent)
Any general pointers greatly appreciated.

Gil
:D

[gary tompkins]

Sounds like you could have a blocked idle jet, so the carbs might have to come off for a good clean. The other thing to try is draining off the carbs and tank, and refilling with fresh fuel. If the bikes been standing a while the petrol can go off, and water/crap tends to collect in the float bowls which flushing through should purge.

[Gil1696]

Gaz
your a star gadgie! I'll try it before attempting to balance again.
Regards
Gil

[spacemonkey]

After draining, put Motorex ...(****, forgotten what it's called! Motorplus I think??) It's a wee blue botle and it absorbs any water into the fuel, and also dissolves gum residue in the carb. Blast around inside the carb first in every tube you can find internally and if you're lucky you might not have to strip. But don't bank on it...

[NattyBoy]

My bikes a similar age & capacity to yours and I had similar problems when I got it. Mate gave it a strip down but one of the screws was seized. Much better but still not 100%. Blasted it with Wynns carb cleaner aerosol though and it seemed to like that for a while..

Nat

[Gil1696]

Thanks for all replies boys.

[SimonH]

Gil,
before you do anything drastic, just check that you don't have an air leak because a small leak will produce these symptoms

good luck

SimonH

[Gil1696]

Nice One.
Are you talking about the area in and around the air box mounting to the carbs or elsewhere on the fuel/air delivery system. Any specifics would be great as I'm gonna go through this as thoroughly as poss using yours and all the above tips.
Cheers Si.
Gil

[SimonH]

Gil

The leak (if any) would be on the engine side of the carbs.

Identical symptoms can be obtained if one of your air screws is loose or if the blanking screw(s) for the carb balancer is either out or missing;

Or there is a leak on the inlet manifold either at the carb mounting rubber or where it joins the cylinder head

The choices are endless I'm afraid!

Simon

[Mick Shaw]

Finding an air leak between the carbs and the engine isn't so difficult. With the engine running spray carb cleaner or easy start around the area you might expect could be letting in air, just stay well clear of the air filter. If the revs rise there is a leak.
Mick.