Carbs driving me nuts

[jackt]

I have posted before and had lots comments and I appreciate all the help.
My 99 Valkyrie I've had couple years 17000 miles has been bubbling or sputtering for some time at lower rpm's I have ran sea foam and Lucas and not seeming to help and really checked for air leaks and sure have none (I have desmoged).
I pulled intakes blown out little holes in carbs which people suggested and made sense.
Some of pilot screws were stuck but sprayed pb blaster and I had to go to youngest son retirement from army at Fort Hood 20 YRS. The next older son retired after 25 yrs and still works for army as civilan. Finally got back and started working on again screws were lose so after all the wiggling lost track when I turned in but I really think couple on road side were less than 1 turn out???????
I replaced pilot screw springs washer and oring screwed out 2 full turns and popping was worse.
So I said 1 more try I added berrymans b12 half 7oz to 3 gallon no ethanol fuel.
Rode until went on reserve then went home really disgusted because it was still popping and sputtering #6 was doing all the popping.
let it cool off a little, had miller, put fan on radiator grabbed my trusty pro motion 45 degree and screwed # 6 in all the way then out 2 turns still sputtering turned in 1 full turn better,,,, played with this adjustment settled on 3/4 turn out no popping or sputtering.
I have not messed with the rest but it sounds good.
The boss had dinner ready so I quit for today.
Is this normal or am I doing something wrong??

Help Help
Update I guess I didn't tell the whole story.
I really don't think po had done any upgrades except 6 pack exhaust when purchased new.
I have digi sync on bike at 900 rpm all 6 are 180 - 190 and it stays pretty constant at different rpms.
and the bike has no air leaks checked many times.
It will run 65 to 95 mph in 5th gear and not stumble or backfire and sounds great.
I guess my real question is would the pilot screw turned out 3/4 turn be normal and sound so good in shop?
I intend to take out again tomorrow see how it runs and sounds.
I have not had tops off but that may be next

[da prez]

  I know you do not want to hear it. S T A R T  over. Start with basics. If a digisynk is available to you , try it. It is a good possibility the carbs need rebuilding. Before that , check and see if you have a fuel line problem. Weakened by age , petcock not working properly.  Are the spark plugs doing their job.
  Forget what you have checked and do a systematic check as if someone dropped the bike off to you for repair. If the carbs need to be rebuilt , then do the full job. If you are unable to , then hire it out.
 A half rebuild will lead to a roadside breakdown.  Honda dealership is N O T  a good place to go for carb work.

                                          da prez

[sandy]

Have you taken the carb tops off to see if the needles are stock or modified? The stock needles have one THIN washer under them. Added washers are sometimes added to enriched the mixture. If you have adjustable needles, they should be on the 3rd notch down from the top notch. I ran mine at the 2nd notch to lean it and got pretty good mileage.

[9Ball]

If you have Cobra 6x6 pipes they tend to run lean.  Also, you haven’t stated what air box filter you are using...makes a difference if it’s OEM vs K&N.  A K&N air filter with Cobra pipes will have you running very lean.

Cobra pipes tend to pop on decel.  This is due to a lean condition when letting off throttle.  What size main and secondary jets are you running.  Cobras can gain horsepower and alleviate a lean condition if you re-jet.  Mine was dyno tuned and we settled on 102 mains and 38 secondaries.  The jet kits come with adjustable needle jets (5 notches that accept a clip) that are typically set in the number 2 or 3 notch (from the top) . If you have stock 100 and 35 jets and OEM needles with Cobra pipes then expect to have decel popping.  Check your plugs to see if they exhibit lean color.

Good luck...

[Pappy!]

I think, when you turned #6 in to 3/4 turn you basically shut that cylinder down hence the lack of popping.
They do run pretty darned smooth at idle on 5 cylinders.
As others have said it is time to go into the carbs.

[Gregory Scott 16248]

I think, when you turned #6 in to 3/4 turn you basically shut that cylinder down hence the lack of popping.
They do run pretty darned smooth at idle on 5 cylinders.
As others have said it is time to go into the carbs.

Pilot screws are to be set at 2 1/4 turns out, that is the factory default and than adjusted per the Honda manual. 3/4 turn setting is almost off.

Greg

[jdp]

You really should check everything before going into the carbs, I’ve had issues that I thought it was the carbs but on one instance the vacuum hose to the petcock had rubbed a hole in it, couldn’t see it Until I started to pull the carbs off, man saved a lot of work , I know I do the same thing think the worst but it’s usually the simple things.

[DarkSideR]

One more easy thing for you to check  .

On the side of each Carb is a small tube. Shown as item #28 in the picture. Over time the ends of the tubes become brittle and crack causing a vacuum leak, and can cause your symptoms.

You can easily see the tube by taking the carb cover off, use a flashlight, and inspect each tube. These can even be replaced (with long skinny needle nose pliers) without taking the carbs off the bike.

Hope this helps. And good luck.