New to me Valk running poorly.

[Vman986]

Well,I found a  Valk I had to buy. A 1999 standard, dressed to a T, including Two Bothers turned out pipes and only 14,500 miles. Bike looked so mint, that I ignored the rough performance (it sat for two years, ridden two or three times annually) and I negotiated the price down from $5200 to $4200.
   Problems arose o the 100 mile ride home. It ran strong on the interstate, holding 75 easily. I thought the quick pace might clear out the cobwebs. But, when I got on the back roads, it stalled whenever it dropped to an idle. Anything below 2000 rpm, it would die with a “clack.” I had to keep the revs up at every stop.
   The other problem is the loud backfire from the new pipes with every shift. I think the pipes were just bolted on with no thought to carb jets or adjustments. I called my dealer and asked about solutions, and he said he doesn’t think he can find jets to solve the issue, and that I should put the stock pipes back on.(which I got from seller.
   Any suggestions that I can arm myself with, before my dealer starts dipping into my wallet? I am particularly concerned about the  quick stall as the revs dip down. (The idle adj screw does nothing) So, thanks for any ideas.     Mike

[WintrSol]

With its history, a tank or two treated with Seafoam or Berryman's B12 could help.
Which idle screw do you mean - the knob that is between the two front carbs on the right?

Also, if you put your general location in your profile or signature, you may find one of use near enough to drop by.

[ridingron]

With its history, a tank or two treated with Seafoam or Berryman's B12 could help.
Which idle screw do you mean - the knob that is between the two front carbs on the right?

Also, if you put your general location in your profile or signature, you may find one of use near enough to drop by.

I'd go for several (4-5) tanks full. The alternative is probably have the carbs gone through. That might even fix the backfiring.

The dealer probably doesn't have a clue on carbs and definitely doesn't want to fix someone else's screw up.

[RonW]

" Bike looked so mint,"

No pics?

The techs at the dealership probably never heard of a Valkyrie. You're better off fixing it yourself.

[Hook#3287]

Sounds like possibly clogged slow jets.

B-12.

[98valk]

might need petcock to be rebuilt.

add TC-W3 to your fuel, will clean everything. see ratio and more info here

https://www.ls1.com/forums/showthread.php?t=91206

[hubcapsc]

All responses sound spot on. Your bike is probably in as good shape
as you thought, only with clogged up carbs... some tanks of treated
gas might make it better.

Don't know where you are... there's several "Valkyrie whisperers"
out there... people who will do a good job a refurbishing your
carbs... there's one near me here in the upstate of SC, and a couple
who are site sponsors with ads that cycle through the banner on this
web site...

I've never had to touch my carbs in 15 years, riding the bike
at least a minimum amount even in the winter makes the
difference... I took my bike to my local Valkyrie Whisperer
last summer and he changed out my timing belts, adjusted
my valves and was perfectly happy with the carbs...

-Mike

[da prez]

Whenever I bought a bike that was dealer serviced , it was issues and problems. There are exceptions. B12 and in a heavy dose
 Run it in and let the bike sit for a day
 Then run it. Someone is near you that will help. Do the basics first. Post your location. We will find you and help.

                   da prez

[Vman986]

Thanks all. I already put  half bottle of B12 in and ran a ten mile loop before rain moved in. No change, but will add more mileage in next few days. I am 20 miles east of Cincy, and would happily pay any Valk techs for their efforts and a cure. If anyone is in reach, feel free to call me at 513-212-9181.

[da prez]

  Mark , mad6gun is in Ft. Wayne.

                                       da prez

[Willow]

If the slow speeds are clogged, and it sounds as if they are, the B-12 running at highway speeds won't get to the issue.  Put in the additive, keep it at or below 3,000 for a good stretch (half a tank or more), and let it sit overnight.  It may take several tanks.

I use a half can of Berryman's to a tank of gas.

You can ignore the suggestion regarding the petcock.  It can't cause what you describe.  If you really do want to apply a new cover set for the petcock, though, it won't hurt.

Oh, and with the popping it may be worth a look or replacement of the air filter.

TBRs don't require re-jetting.  Find a new motorcycle shop. 

[98valk]

If the slow speeds are clogged, and it sounds as if they are, the B-12 running at highway speeds won't get to the issue.  Put in the additive, keep it at or below 3,000 for a good stretch (half a tank or more), and let it sit overnight.  It may take several tanks.

I use a half can of Berryman's to a tank of gas.

You can ignore the suggestion regarding the petcock.  It can't cause what you describe.  If you really do want to apply a new cover set for the petcock, though, it won't hurt.

Oh, and with the popping it may be worth a look or replacement of the air filter.

TBRs don't require re-jetting.  Find a new motorcycle shop. 

OP - "Anything below 2000 rpm, it would die with a “clack.” I had to keep the revs up at every stop."

if the diaphragm has failed enough losing vacuum to keep fuel flowing, increasing rpms increases vacuum to a higher vacuum level keeping the diaphragm open allowing fuel to flow.
might be the problem and maybe not. just something most don't think to check.

[Willow]

If the slow speeds are clogged, and it sounds as if they are, the B-12 running at highway speeds won't get to the issue.  Put in the additive, keep it at or below 3,000 for a good stretch (half a tank or more), and let it sit overnight.  It may take several tanks.

I use a half can of Berryman's to a tank of gas.

You can ignore the suggestion regarding the petcock.  It can't cause what you describe.  If you really do want to apply a new cover set for the petcock, though, it won't hurt.

Oh, and with the popping it may be worth a look or replacement of the air filter.

TBRs don't require re-jetting.  Find a new motorcycle shop. 

OP - "Anything below 2000 rpm, it would die with a “clack.” I had to keep the revs up at every stop."

if the diaphragm has failed enough losing vacuum to keep fuel flowing, increasing rpms increases vacuum to a higher vacuum level keeping the diaphragm open allowing fuel to flow.
might be the problem and maybe not. just something most don't think to check.

A good reason not to think of it.  If the petcock is no longer delivering fuel it won't die quickly.  It will take at least two miles normally to empty the bowls.  At idle it would take five or more minutes.

[darryb63]

Please run as fast as possible from a dealer. Their billing systems don't work well for Valkyries. I bought a similar dressed 2000 Valk model that had sat for 1.5 years. Dealers in CA were crazy expensive. Shipped it back to Phx. Had carbs, tank, vacuum lines cleaned for $700. Total bill was $1300 that included front tire, front brakes and leaking fork. Now I'm so happy cruising all the freeways. $$$ but totally worth it.

[rug_burn]

     It may be a matter of just rebuilding the carbs, including replacing or cleaning out the various jets. 
     If the previous owner told you it's been sitting for 2 years, it's probably twice that.   But the job may not be that hard.   Carb rebuilding and tuning are a big topic here, as our bikes get older.
    On mine I had to replace 1 carb diaphragm ($100 right now)  and probably should have replaced all six, assuming freely flowing cash...   But it runs real good, after a rebuild of all six.

[gordonv]

+1

If the slow speeds are clogged, and it sounds as if they are, the B-12 running at highway speeds won't get to the issue.  Put in the additive, keep it at or below 3,000 for a good stretch (half a tank or more), and let it sit overnight.  It may take several tanks.

I use a half can of Berryman's to a tank of gas.

High gear, at low city speeds. 30-40 in 5th. Cheaper and easier than a carb rebuild, and it might just work. After about 2-3 cans, try a different brand. I use the B-12. Also, I try to buy fuel at Chevron for the Techron.

[RonW]

I'd splurge for Marine Stabil in this situation.

[indybobm]

Agree with previous suggestions.  1/2 can of B12 to a half tank. When ridding in 5th gear. Constantly vary the RPMs from 1500 to 2000.  You want to accelerate from 1500 to 2000 to draw the gas into the slow jets, then let the bike slow to 1500 and do it again

[rug_burn]

    Me, I tried every one of those fuel system cleaners, all to no avail.   One of them, I know not which, made some holes in the vacuum lines, which were then new.
   And that's another thing that needs to be checked:  all those 3.5mm and 4.5 mm vacuum and fuel vent lines go bad and leak in time.   Those leaks usually cause backfiring on decel, and probably rough idling.

[Valker]

If a fuel system cleaner ruined vacuum lines, you have MUCH bigger problems than dirty carbs. There should be zero gasoline in any vacuum line.

[rug_burn]

Make that:    -had- much bigger problems.    It's fixed now after being rebuilt and synched, but gas treatments didn't do anything

[Valker]

Make that:    -had- much bigger problems.    It's fixed now after being rebuilt and synched, but gas treatments didn't do anything

Did you replace all the vacuum lines also?

[Bagger John - #3785]

I'd splurge for Marine Stabil in this situation.

It's a good stabilizer, but not a good carb cleaner.

[RonW]

If memory serves, Stabil worked very well cleaning out the carb jets. Even the red Stabil.

[Dr K]

Check the little rubber vacuum caps on the backside of the intake tubes just above the cylinder heads only one has a hose attached the other 5 are capped they can split and leak-fall off