Top end hesitation

[GL15Brewer]

So I finished putting the carbs back together. Everything seems to be running fantastic except some top end hesitation. At about 4000 rpm it feels like it has no more to give. I am idling slightly high at about 1200. Didn't notice the hesitation to begin but may have been just giddiness from stating it up. Any thoughts or suggestions appreciated. Thanks again for all the help and support though the biggest bike project I've completed so far.

[Steel cowboy]

It sounds like fuel starvation
The main jets start to come on line at about 3000 RPM. As you continue to advance the throttle if your floats are not properly set up you will feel fuel starvation. You might have enough fuel in the bowls for the low speed jets. You may want to check your fuel line too, a slight dip or hump could starve the carburetors too. Is your petcock flowing a good amount, test that too.

[Chrisj CMA]

Mine did that shortly before more serious starvation due to a failing petcock

[GL15Brewer]

All the fuel lines are new after the rebuild. Per the clymer book I have I have the a/f screws set at only 1.5 turns out. Could that be the issue. I plan on pulling the petcock and cleaning that.

[WintrSol]

All the fuel lines are new after the rebuild. Per the clymer book I have I have the a/f screws set at only 1.5 turns out. Could that be the issue. I plan on pulling the petcock and cleaning that.

Fuel line routing can cause a reduction in flow. Also, do you have an in-line filter or shut-off valve installed? BTW, the A/F (pilot) screws don't affect fuel flow after the throttles are a bit above idle.

[GL15Brewer]

No filter installed. I cut all replaced lines to the same length. And good to know about the pilot screw. It very well could be my imagination because I have a tendency to be paranoid after any finished projects. Lol. I will have to continue to monitor.

[WintrSol]

Just a side question, which is unlikely to affect operation at that much throttle, but did you sync the carbs? If not, and you're anywhere near St. Louis MO, you're welcome to use my Digisync.

[Steel cowboy]

After I rebuilt my carburetors on my interstate I set all the air adjustments to 2 1/4 turns
you may want to check with others on that I know it does not affect throttle about 4000 RPM

[GL15Brewer]

I'm in Utah thanks so much for the offer though. I "synced" the carbs using d ray Smith's method on YouTube. Set the throttle valve to cover half of the last small hole in the carb. Not sure how accurate it is but it's what I had to work with to start at least.

[The emperor has no clothes]

I'm in Utah thanks so much for the offer though. I "synced" the carbs using d ray Smith's method on YouTube. Set the throttle valve to cover half of the last small hole in the carb. Not sure how accurate it is but it's what I had to work with to start at least.

Where bouts in Utah ? I get up to St. George occasionally. A DigiSync is going to be a lot better than that bench setting. But I doubt that's what's giving you the dogging at revs. Since you cut the fuel lines to the OEM length, I would start with checking the flow out of the petcock. If it's slow a rebuild kit is in order. (Are you sure the fuel lines were stock ?)

[GL15Brewer]

I'm at the south end of the salt lake valley. Its about 4ish hours north of st George. I cannot be positive they are stock but due to the crumbly nature I am assuming they were quite old. It did not have the issue prior that I can remember. Also if the condition of the carbs is an indication of what the petcock looks like I'm guessing that's likely needing rebuild as well. Wife is having me start a bathroom remodel so not sure when the valk is going to go back on the stand. Shouldnt be long, it's a small bathroom. 

[Jims99]

I had a similar problem and found one of the slides wasn’t working properly. Just one carb but made a big difference with power loss. Ended up being a blocked air passage. Runs great now.

[GL15Brewer]

I'm at the south end of the salt lake valley. Its about 4ish hours north of st George. I cannot be positive they are stock but due to the crumbly nature I am assuming they were quite old. It did not have the issue prior that I can remember. Also if the condition of the carbs is an indication of what the petcock looks like I'm guessing that's likely needing rebuild as well. Wife is having me start a bathroom remodel so not sure when the valk is going to go back on the stand. Shouldnt be long, it's a small bathroom. 

MeatHead if I cannot find some help up here before the weather turns I'd love to try and meet up somewhere. I could find a weekend or something to run down the Arizona way if you are willing and have the means to help with a sync.

[Timbo1]

If your needing to sync the carbs an easy and cheap (about $20) diy way would be to make a manometer with some vinyl hose and a reservoir to hold some transmission fluid.  I made one using a 6 way aquarium valve and it worked fantastic.  If your interested search the tech board for "manometer".

I originally built one with a 2" pvc reservoir but had trouble getting it sealed properly so I made another using this 6 way valve and it worked perfectly.

 https://www.amazon.com/gp/product/B07FKQ3CMZ/ref=ppx_yo_dt_b_asin_title_o04_s00?ie=UTF8&psc=1

[The emperor has no clothes]

I'm at the south end of the salt lake valley. Its about 4ish hours north of st George. I cannot be positive they are stock but due to the crumbly nature I am assuming they were quite old. It did not have the issue prior that I can remember. Also if the condition of the carbs is an indication of what the petcock looks like I'm guessing that's likely needing rebuild as well. Wife is having me start a bathroom remodel so not sure when the valk is going to go back on the stand. Shouldnt be long, it's a small bathroom. 

MeatHead if I cannot find some help up here before the weather turns I'd love to try and meet up somewhere. I could find a weekend or something to run down the Arizona way if you are willing and have the means to help with a sync.

Absolutely 

[GL15Brewer]

Timbo1 I may give that a try just to get by for now and see if it makes a difference. also looked at the pingle PC but not going get financial clearance to make that happen right at this time. Ill pull the OM PC and see about getting it cleared up and what happens there. Was also brain storming and remembered one of my vacuum nipple block off was cracked. Could that also be my issue?

[Grandpot]

Here is a link to a 6 station manometer.   Easy to make.  The biggest advantage of this one is you see all six carbs at once and can balance them together.
http://www.valkyrieforum.com/bbs/index.php/topic,53044.0.html

[Timbo1]

Timbo1 I may give that a try just to get by for now and see if it makes a difference. also looked at the pingle PC but not going get financial clearance to make that happen right at this time. Ill pull the OM PC and see about getting it cleared up and what happens there. Was also brain storming and remembered one of my vacuum nipple block off was cracked. Could that also be my issue?

I'm not a carb guru but don't think you could correctly sync if you have a vacuum leak.  Out of sync carbs would lead to imbalance, poor performance / power delivery imo.  So I'd want to make sure there's no leaks on the vacuum nipples, intake tubes & seals and then sync the carbs.

When I used the manometer I synced them at 800 rpm and then 3000 rpm, it took several times circling the bike cylinder by cylinder to get them all to match #3 on the manometer and was worth the time doing it.