I currently own a 1979 Yamaha XS1100 motorcycle.
I have been trying all summer to get it running and have succeded, The only problem I am having now is it wont run off high choke and no matter what I try I can't seem to get it to run correctly.
I have not rebuilt the carburetors and I flushed the tank and put in new gas. I disassembled the carbs according to the manual but it gives no set for the airflow jets in the front.
All other adjustments are exactly where they need to be, I can't use my manometer on them untill I can get the machine to run off choke and Idle correctly.
Please help
Sincerely,
Completly disgruntled

sounds like either plugged jets or seriously missadjusted carbs

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I'll take a closer look at them, If you have any other ideas I'm all ears.

Stelos, not sure if your carbs have a true choke that restricts air inflow or what's known as an "idle enrichment circuit" that feeds more fuel when activated. Probably the latter. If it runs this way but not at idle with the choke deactivated it is probably plugged pilot (AKA idle) jets. The pilot jets are very small, look like the main jets and can be accessed with the bowl off. Also it takes almost nothing to block them so this is a common problem. Remove and clean them with carb cleaner and a very small wire (you won't believe how small the hole is when you look through one). Also clean any air passages adjacent to them. You don't say whether the bike will run when throttle is applied and the choke is off. If so, that points more to the pilot jets. They provide fuel from idle to about 15% throttle opening at which point the main jet/needle circuit comes into play.
Good luck.

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1983 M-B 240D-Gone too.
1976 M-B 300D-Departed.

"Good" is the worst enemy of "Great".

It will run when I throttle it up to 3-4k rpm this includes the choke (a.k.a fuel enrichment valve) off, But the moment I try to go to idle is dies, It will start right back up but only with the choke on.
What type of wire can I use on that, Can I use the round file you would use on cutting torch heads? I will go completly through the carbs again with a "fine tooth comb" as it would be.

I feel your frustration. My BMW F650 had those symptoms even though I had not touched the carbs. (Yes folks, carbs. A single-cylinder with (2) carbs, one for each intake valve. But I digress...)

The idle circuit of most carburetors is adjusted at the factory and then sealed, so I figured that if it had been running and now was not, there must be some problem other than being mis-adjusted.

I then hit on the idea that since I had not actually ridden the bike for some months, that the gasoline might be stale. I drained the tank and put in absolutely FRESH premium grade gasoline. I started it on "choke" and let it idle for some time to get really warm, then tried to ride it. It needed gentle throttle movements and occasionally sputtered and stumbled for a few miles, but the fresh gas with all of its volatile components intact burned better, and the premium with its load of detergents eventually dissolved and cleaned out the idle circuit jets.

My understanding now is that combustion was marginal after most of the more volatile and easily-ignited stuff had evaporated from the old gas in the tank and that some scum in the idle circuit was the last straw.

The bike has been running fine since, and I make sure to empty the tank regularly by riding often (whee!) and buying only premium.

So, if your Yamaha has been not running a long time, try fresh gas. It only takes about a gallon in your tank to prove one way or another, and might save you hours of frustration.

If you don't have access to fine wire try yanking a wire from a wire brush. Be careful though, the steel wire can scratch the brass jet and alter its characteristics. Also I have used strands of wire from electrical wire like speaker wire or lamp cord. Less likely to damage the jet but not as stiff and harder to poke through. There are air passages associated with the idle circuit also. Spray carb cleaner through all these.

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1983 M-B 240D-Gone too.
1976 M-B 300D-Departed.

"Good" is the worst enemy of "Great".