2 valkyries both rebuilt carbs same problem.

[Racernick]

Hello all

So I decided to help out my father in law who own a 99 and a 2003 interstate. He let them sit too long so they didnt wanna run. Order a few kits up from ebay and tore them apart and rebuilt them and had alot of trail and error on the first bike and so on. Well after all said and done carbs were fully disassembled from the rack and put each one in a sonic cleaner to be super cleaned then completely blown out with compressed air. ( i didnt remove the butterfly just for reference) then I assemble with all part included with kit. ( slides were re used and in good shape, also plastic floats were re used as well) after all assembled and set the air mixture to 2 turns out put back on bike with air box fires right up idles great but when you go to revv it up around 2500 it like ot runs out of fuel and fall on it nose until it get enough fuel back to the carbs. Carbs have all new fuel and vacuum line made sure nothing in kinked or bent restricting anything. Even left the fuel cap open thinking maybe it was the vent didnt help. We have a digi sync and they arent too far off but could for sure be dialed in alot closer to Be perfect.  Anyone have a issue like this ? Really need some help would like to get out riding. Thanks in advance

[Knapdog]

Try turning it 2 and 1/4 turns out to Honda's recommendations.

[Steel cowboy]

When you rebuilt the carbs did you check the float hight. Check your petcock is supplying enough fuel.

[hubcapsc]

put back on bike with air box fires right up idles great but when you go to revv it up around 2500 it like ot runs out of fuel and fall on it nose until it get enough fuel back to the carbs.

Do you have the bikes fully assembled and are you experiencing your problem on your road
tests, or are you doing some kind of bench test? If you're doing bench tests, don't
underestimate how fast and how much gas needs to be delivered to the carbs when
you turn the throttle...

-Mike

[Jims99]

How is the fuel? Maybe add b12 or Techron to help. Sounds like petcock issue but also check all vacuum lines and caps again. Some of those eBay kits aren’t the best, jets could be wrong or not drilled correctly. You could always ask wood butcher over on MeWe, he’s great with these bikes.

[Challenger]

Are your enricheners completely closing? Interested to see pics of 2003 Interstae
Interstate  

[da prez]

Air box must be fully installed . The intake hoses from the carb tend to link. They must be fully seated. Put a vacuum pump to the petcock and check fuel flow. Do not assume anything. Gas could be an issue.  I use an I V fuel supply. Petcock filter could be partially plugged. Make sure you have good vacuum for petcock. A lot of items to check.

               da prez

[98valk]

When you rebuilt the carbs did you check the float hight. Check your petcock is supplying enough fuel.

float height of these carbs is non-adjustable. they are preset by Honda.

[Chrisj CMA]

If the problem is exactly the same on both bikes it would be unlikely that the issue is with the tank, petcock or anything else other than the work you did. Double check everything, fuel lines, vent lines. It’s something you did or didn’t do the same on both.

[WintrSol]

If the problem is exactly the same on both bikes it would be unlikely that the issue is with the tank, petcock or anything else other than the work you did. Double check everything, fuel lines, vent lines. It’s something you did or didn’t do the same on both.

And pay close attention to fuel hose routing, likely done the same on both bikes, looking for any kinks, or hills for the fuel to climb.

[Racernick]

To add more info

I took the stock petcock off with the vacuum and added one from a cbr600 as others had suggested and it had alot of flow when fuel line is removed. Both petcocks brand new so no clogging and tanks have been clean as good as i could. All fuel is new and 91 octane but it california fuel so its as good as it comes.

I road tested the 2003 and it would take off if you baby the throttle then stumbled if you had it around 2500 rpm but the. I yave it more throttle and seem like it got fuel back and would take off. Really hard to have a smooth ride when you dont have goo throttle control. 

I have the air boxes both on and everything as it would be ready to ride. I have checked air box tubes to make sure they are not rolled and tried to seat as far doen and as tight as i could get. The one bike i removed the air box so many times i wanna re seal the tube where it goes in the air box jusy to be safe. If anyone has recommendations what to ise other then silicone please let me know.


As stated above the floats are pre set from factory so no adjustment that can be made i even thought maybe plastic on float is off or something but not sure.

On the 99 i went overly crazy on making sure the fuel line and vacuum lines are right and nothing kinked in any way and i even double checked the other and still same issue.

All the vacuum hoses and fuel lines are brand new and all the vacuum caps are new as well.

As for the 2 1/4 i have yet to do that but will try it.

Not sure what the enricher valve is but how would i know if it fully open ?

[WintrSol]

Not sure what the enricher valve is but how would i know if it fully open ?

Most just call it the choke, controlled by the thumb lever on the left grip. They have to be adjusted to move the same amount, and at the same time, and to make sure they all close fully. If you take the chrome covers off the left and right carbs, you can see them in action, and measure how far the brass valves are pulled.

[Racernick]

Not sure what the enricher valve is but how would i know if it fully open ?

Most just call it the choke, controlled by the thumb lever on the left grip. They have to be adjusted to move the same amount, and at the same time, and to make sure they all close fully. If you take the chrome covers off the left and right carbs, you can see them in action, and measure how far the brass valves are pulled.

With that being said yes they care completely opening and closing as it should. I havent out the chrome back on since rebuild.

I feel like im missing something simple most likely they idle so well

[The emperor has no clothes]

Not sure what the enricher valve is but how would i know if it fully open ?

Most just call it the choke, controlled by the thumb lever on the left grip. They have to be adjusted to move the same amount, and at the same time, and to make sure they all close fully. If you take the chrome covers off the left and right carbs, you can see them in action, and measure how far the brass valves are pulled.

With that being said yes they care completely opening and closing as it should. I havent out the chrome back on since rebuild.

I feel like im missing something simple most likely they idle so well

Did you use new fuel line ? If so, did you lengthen it at all. Even a slight extra length will result in a kink with the engine warmed up. I’d also check that the vent lines aren’t getting kinked.

[hubcapsc]

when you go to revv it up around 2500 it like ot runs out of fuel and fall on it nose until it get enough fuel back to the carbs.

I took the stock petcock off with the vacuum and added one from a cbr600

I hope you figure it out... if it comes down to it,  it would be interesting to put an OEM petcock
and OEM fuel lines (TUBE, FUEL - 17701-MZ0-000 anyhow) back on one of them...

-Mike

[98valk]

check the slides and their diaphragms for damages.  check that the slide needles, washer and springs are installed correctly per the tech manual.

[Mooskee]

From what you have described the problem is common to both bikes. Look for something you did, or didn't do, or a problem in the carb kit. If the kits are All Balls, they are good kits with the exception of the bowl needle valves. Their bowl needle valves cause the floats to sit too high. I use K&L 18-8955 float bowl needles.

As mentioned set your pilots to 2 1/4 turns out. May not be perfect, but it will be very good.


Use your Digi Sync and balance the carbs ro within a digit of each other. That is probably not the issue, but can be a contributing factor.

Make sure the drool tube etc are connectedd to the bottom of the air box.

If you removed the 1-2 coil during carb removal, make sure the wires are connected to the coil.

If the carb kit is one of those really cheap Chineese kits, I would be very suspicious of the jets and needles.

I hope you get it figured out quickly. Be sure to let us know the answer.

[franco6]

Sounds as if you are getting too much air . Make sure the intake manifolds ( shiny tubes) have fresh o rings and are tight. . Check for air leaks every where. 
 

[da prez]

  Back to the enrichners , are they properly installed. Meaning , captive on opening and closing. They have a slot that works the needles. All six (three each side) must work together . Be sure a slide needle has not come loose.  W E  M U S T  K N O W W H A T  I S  W R O N G.  

                                            da prez

[Led]

Once these carbs are "gummed up", I don't care how much cleaning and adjusting one does.

SURE!  You can get it to run, but for some reason, they just never run "totally" right ever again?   It cannot be just me, that realizes/imagines this!!      

[Mooskee]

Once these carbs are "gummed up", I don't care how much cleaning and adjusting one does.

SURE!  You can get it to run, but for some reason, they just never run "totally" right ever again?   It cannot be just me, that realizes/imagines this!!      

If you ultrasonically clean them correctly, and replace the O-rings, needles, and jets and bowl float valves, and then balance and tune them, they are as good as new. Done it many times as has Attic Rat, Wilder and many others.

[98valk]

Once these carbs are "gummed up", I don't care how much cleaning and adjusting one does.

SURE!  You can get it to run, but for some reason, they just never run "totally" right ever again?   It cannot be just me, that realizes/imagines this!!      :'(

use TC-W3 in every tank. cleans and lubricates everything.

https://www.ls1.com/forums/f48/been-testing-oil-91206/

[rug_burn]

I've rebuilt mine, and have had the same problem.   They always end up running too lean. 
   On mine I just enrichened the idle screw (or whatever the carb's one-and-only adjustment screw is called) until they pulled smoothly at the low end, using that technique with the IR thermometer from Harbor Freight..   Some of them are probably a turn or even two more open than the standard 2 turns.

   It seems that just using an ultrasonic cleaner with Simple Green and water is not enough for internal passages.   And some of the holes in those jets are only .012" dia, which is so small it's hard to even get a piece of steel wire to shove thru it.

   A friend was telling me that he had to soak his carbs in Liquid Wrench several times to get out the gunk from his gunked up carbs.   He said he'd soak it overnight, and could see dark colored stuff coming out of certain passages.  After several times it came out clean;  and that seemed to solve it.  But can you even buy  Liquid Wrench in cans anymore?

[Knapdog]

Would soaking the carbs in Evaporust have the required effect of cleaning them?

[Ron in Buffalo]

I used “Crud Cutter” and  ultrasonic tub it did the job. I bought it at TSC.

[rug_burn]

I'd be careful with something called Evaporust, mainly because to quickest way to eliminate rust is just to apply an acid, which may also eliminate some of the metal of your carb.  Better to stick with petrochemical cleaners.

But to the original question of resetting the mixture after  heavy applications of dried fuel gunk:

I have done repeated temperture checks with that IR non contact thermometer, and I got mine running pretty darn good.  hardly ever does it show signs of being too lean, the usual result of residual gunk in the carb. I've probably done that procedure 8 times now at least because I was hesitant to open the screws too much.  After a few times you just say: hell, open that one 1/2 or 3/4 turn, and it ends up still being too lean.

I plot the results of all my tests in an excel file, which is hard if you've never done it before.  you can see pretty clearly which ones are too lean, but not exactly how much to enrichen them.  I'll email the file to anyone who wants to see it, but you gotta have MS Excel to use it.

     The signs of too-lean carbs:
1.  Too-hot exhaust (obvious)
2.  Hesitation when increasing or opening the throttle even a little.   The power should be 'right there'  even with tiny increases.   And any sagging at more open throttle settings also means you're too lean on some of your carbs.
3.  Having to use the choke or starting lever to keep it running at idle when you first start it.  Remember how you didn't really ever need to use choke unless it was really cold out?   That's how it should be when correctly adjusted.
4.  Uneven power pulses at real low rpm under load.  

Once you get the carb mixtures close to right, the bike becomes pretty normally drivable above about  2000 rpm, and you can fine tune from there 'til it's good enough for you.  Perfect is pretty hard to achieve with our crude analytical tools, it appears to me...
    I'm never sure if I'm imagining roughness that I just never noticed before, but was always there, or if it's actually still a little rough.    I never paid that much attention until I let it gunk up!   Every adjustment I've made has made it run better, however,  and now it's damn near like the factory setting, so don't give up..!


 

[hubcapsc]

I first learned about evaporust here, when I was using oxalic acid to remove rust.
Evaporust is PH neutral. I don't have a clue if it would be good for cleaning a
carb, but its not acid...

I think it was Grumpy who was talking about evaporust then...

-Mike

[Racernick]

So finally got to work on the bikes again. Took the carbs back off went back to original jetting instead of the one i got with the kit from eBay. Change the needle back to the original in the slide. Everything seems to be running like a top getting ready to test drive it make sure its perfect. Will have to tear into the other one soon and see if it fixes the issues on that one as well.

[Racernick]

Test Ride went awesome just had to do some more fine tuning on the digi sync and she was money. went searching for some parts for the other bike and found them all at VALKYRIE CARBS AND CUSTOM, David was awesome to talk to and very helpful and very quick to reply really recommend if you need some help with rebuilds or parts, he will be you guy if you're not willing to do them. thank you everyone for all you input on everything happy to stop pulling my hair out with these issues happy holidays

https://valkyriecarbsandcustom.com/