Rough running diagnosis

[Dak44312]

So, I'm a little stuck on this one. Just bought a poor-running '98 with 13k on it. Figured with the low miles, carbs were due for cleaning. Didn't see anything crazy in the process. All slow jets looked good, float valves working, etc. I am assuming by clamp positioning and general appearance that they had never been out. All of the mixture screws were at 1.5 and I kept them there. Don't have gauges, but the "bench sync" looks good (butterflies in matching position).Fired it up with my IV setup, doesn't idle at all and runs like its on 5 cylinders below 2000 rpm. It cleans up at higher rpm (at least with no load on it).  Spark seems good on all 6, but I haven't performed any measured tests. What's the next logical step?  Is there anything in the ignition system that could cause this symptom?

[3W-lonerider]

you have plugged up slow jets.
you may have looked at them but unless you removed them and looked threw them into a light. you didn't actually see anything.
I done the same thing to a set of carbs a couple of years ago.
even took them out and looked threw them into a light. all of them looked to be open. wasn't until I replaced all of them that the bike would actually run properly.
heres  a test for ya. start the bike from a cold start. take the choke off as soon as you can without it stalling out. then start spraying water on the exhaust headers
while the bike idles. I bet there will be at least 2 headers that will not steam the water off and the rest will.

[da prez]

  Start on the basics. Check for vacuum leaks at the lines , intake runners ,intake connections.
 Assume it is in need of everything , but do it by a process of elimination. Check each item  in order and do not skip around. Be sure they did not put an inline fuel filter in it . You are fueling with an IV bottle ( I read?) so fuel supply is not an issue. Let us know.

                          da prez

[Dak44312]

I inspected all of the slow jets in the sun and made sure the orifices were clear and round. I just went through the same process last week with my I/S and it runs beautifully. The bike will not idle, choke or not. It almost seems like the choke circuit isn't even working. No inline filter with the IV. I have the #6 vacuum line plugged until I put the petcock back on.

[WintrSol]

The idle jet feeds into the pilot circuit, mixing with air from a jet in the intake of the carburetor. After that mixing, it goes past the pilot screw, and the hole the tapered end of the pilot screw goes into can easily clog. Did you take the pilot screws out, and verify that those holes are clear?

[old2soon]

Are you doing your testing with air box on or off-with or with out air filter? RIDE SAFE.

[Dak44312]

I did remove the pilot screws and blew air through those circuits. Air box on, with filter.

[Pappy!]

First off....start your initial setting at around 2 1/4 turn out from a lightly closed position. Won't hurt a thing. Do this as a test if nothing else.
Read the mixture setting procedure in this if you want.

http://www.valkyrieforum.com/bbs/index.php/topic,77968.0.html

There is no hard and fast rule that says all carbs must be set at exactly (X) number of turns from closed.

[Patrick]

I agree that if this monster has 35 low's then 1.5 turns is not enough. Factory is usually 1.75. Set them at 2.25. [Seems that you might have 38 lows which would make the setting OK]
Also, I think you have plugged low circuit. How did you clean them other than with air ?  Spray some cleaner thru them then the air.

[Dak44312]

I thought 1.5 seemed odd too. I had 5@ 1.5 and 1@1.75. Still has 35/100.  Unless someone had the tool previously, that was the factory setting. I slotted them all when I had them apart. The low circuits blew out using  Berryman spray and compressed air.

[Patrick]

I thought 1.5 seemed odd too. I had 5@ 1.5 and 1@1.75. Still has 35/100.  Unless someone had the tool previously, that was the factory setting. I slotted them all when I had them apart. The low circuits blew out using  Berryman spray and compressed air.

Well, if you're sure the low circuits are clean, then maybe re-setting the pilots will fix it. You are describing a classic plugged low jet/circuit problem.
Make sure the airbox is installed correctly, its easy to screw up the connections on the inside.
There is not much to the ignition system and they are pretty bullet-proof.

[Ricky-D]

There are four apertures in each carburetor plus a gallery for the apertures, that

are the low speed circuit in the Valkyrie  carburetor.

I would never recommend blowing out the small passages (from the source

of the opening) for that can clog and block up the passage with the crud you are

aiming to clean out, and also possibly blow out a factory installed plug.

The force of air should be in reverse to the normal flow of the gasoline.

This would take a blow gun with a right angle attachment to direct

the flow of air down into each aperture and of which (the four) are located in the bottom

of the carburetor throat. Naturally you would be most affective if you remove the slow jet

from the carburetor first.

***

[Dak44312]

I will recheck the boots. If I have a curled lip on one of them, would that be enough to cause my symptoms?  I can't believe it won't idle because of that???

[Dak44312]

OK, so all the boots were good. I had two issues. There was a hole in the vacuum line that ties #3 and #4 to the PAIR valve. What I'm most embarrassed about is the idle screw that was turned almost all the way out.  Oops. The throttle is still hanging just a touch and there is a slight hesitation off idle , but I suspect I need to re-sync the carbs and all will be right with the world. Thanks for everyone's input. Do you guys concur on the sync?

[Patrick]

I'm kinda surprised that you didn't desmog while you had the monster all apart, but, if you now have all new hoses and caps thats OK.
Have you reset the pilots to 2.25 ?
A sync may very well be in order. I just use a simple single vacuum gauge.

[Pappy!]

Have you reset the pilots to 2.25 ?
A sync may very well be in order. I just use a simple single vacuum gauge.

Yeah....seems like he just ignored that part. Let us know.