Here's one for ya...Black sooty plugs(all 4)

And bike won't run unless choke is on...Well it runs for several seconds after choke is of then (VVRRRTTT) it cuts right out..Won't start again until I choke it???

 

if i recall, sooty plugs = rich mix. If it won't run at all without choke I'd guess theres some mess in the carbs that needs cleaned out!

 

No..these carbs are so clean i could eat out them...if i spend much more time on this bike i may have to eat out of it....see cause my wife may make me eat outside?? ok that wasn't funny but either way..they are clean

 

first of all what kind of carbs are on you bike my 550 had mikuni and i hat the same problem i thought i cleaned them good enough but i forgot to take out the pilot jet and hit it with compressed air to clean it out, the pilot jet controlls the flow of fuel at idle to about 3-4k rpm then the main jets take over, and if it is only running with the choke on then that means that you are using the emulsion tubes as your pilot jets, and that will make it run real rich, take a look at it and let me know

 

I took all jets out...everything...only thing i didn't do was separate the carbs..there are a few small cracks around the boots?? i have the mixture screws turned out 2 1/2 right now also

 

ok lets go step by step, for the cracks in the carb boots take a portable propane torch and turn it on, but don't light it and with the bike started and idling" with the choke on in your situation" run the flameless propane over your carb boots and especially in the cracks that you can visually see, the idle will change if a crack goes all the way through, you can also do this with a can of either "starting fluid" but it can get messy, and im sure that you know that the more you have the mixture screws out the more fuel it lets in, and it it is only running with the choke on and when you turn it off" no more fuel coming in from the emulsion tubes" and it dies then it needs more fuel from the pilot jets, try turning them out at half turn incriments, and see if that helps, if you need mew carb boots i just ordered a set for 86$ with free shipping from www.carbkitscapital.com

 

Also - simple as it sounds check the air box isn't full of rats.

 

I did a float level test to 1 carb anyway..it comes about 2mm below where it should?? for the 3mm test...would that starve my carbs?

 

The sooty Plugs are from running it with the Choke on.
The stalling after a few moments is the Starter Jet Well in the Fuel Bowl running-out of the meager supply needed for starting the the Bike.

No Idle is Pilot Jets RELATED
Clogged Pilot Jets
or
Clogged Pilot Jet Passage
or
Clogged Pilot AIR Passage
or
Pilot Mixture Screws not opened enough for Fuel to be brought-in with the Pilot Air.

All of the above!

I think I'd try setting the Pilot Mixture Screws a few DEGREES short of 3 Full Turns OUT and see if there's life in the Fuel Delivery System.

You can tweak the Pilot Mixtures after you get the bike started and idling in some kind of way.

 

I actually just had them in 1/2 increments to 4 1/2 out to no avail...going to try the propane in a second..but im wondering if my floats are stopping fuel from the level its supposed to be? as i said the tube level when it's barely running is about 3-4mm under the 3mm area it should..so about level with the bottom of the screw??

 

ok....now what it's doing is when i have the choke on is idles at like 4200 rpm..when i turn the choke off it runs for about 5 seconds then drops down to nothing and dies...did i mention that while its running its backfiring through the carbs? i checked the level again with the bike more level and now the gas is up to the screw??// bye the way i have all 4 mixture scres out to 3 1/2 now...what a weird deal....Does anyone know if the plates that hide the air jets in the top of the carb are needed..this bike didn;t have any with it...a mechanic friend said he didn;t think they were needed...these are the little steel kidney shaped plates that have 1 screw holding them in place over the shallow cavern that houses the air jets.......

 

When you say i'm using the emulsion tubes as the pilot jet? you mean ??

 

i don't know what brand carbs you have hitachi or mikuni, but on my mikuini's they have a little emulsion tube, little brass tube that sits in the float bowl and when you engage the choke it opens the tubes and allows fuel to be drawn straight up into the engine, so it will have sufficient gas to start up, it is sopose to idle high with the choke on then when you take it off the pilot jets take over the idle, are you sure your idle is set high enough?, let me know what kind of carbs are on your bike and i can help you out alot more

 

I just realized somthing, I looked at the plugs and they are BR7es..calls for Bp7es....he plugs a very different looking believe it or not.. The porcelin part on the Bp7es actually dips below the plug like normal in the other they are hidden? I wonder if that has anything to do with it? well see.....

 

I had the same problem as you all 4 plugs were black sooty mixture screws didnt change anything. I went to a hotter plug BP6ES and now my plugs are brownish tan colour.

 

Well i found that the prevoius owner used br7es plugs insyead of bP7es..put the right ones in and it starts now.......leaving a post about it as a main post..