Mid range hesitation

[Stillsmokey]

I've got an 05 RX1 Mountain, K&N filters 165 Main jets, Holtzman Red Springs, 2100Ft elevation.

I've cleaned and synch'd the carbs, and it idles and runs well except for a mid range miss around 6-7k rpms. I can power thru it and the top end is strong, but it bogs out in the midrange. I've tried switching back over to stock springs, and that's way worse, wondering if i need to move needles or change any other jetting.

 

[mbarclay]

I have the same problem did you ever find a solution?

 

[dhkr123]

You might try loosening the pilot screw (standard ~2 turns out) a little and/or raising the needle. Pilot screw will increase the fuel at idle, needle will increase fuel sooner when opening throttle. Remember that you have increased the air flow -- need more fuel along with it and mains only affect high speed.

 

[Stillsmokey]

I'm in the process of trying needle adjustments now, i've moved the clip up to the 2nd notch to try leaning out the midrange, but i broke one of the slides(those stupid little clips) so i'm waiting on those to arrive, will post results when it's fixed

 

[dhkr123]

.. hate doing that

 

[Bamboozler]

I only can add that a few years back when my friend bought a Hauck filter kit/jets the setup sheet instructed to move the needles one clip position richer or one clip position lower on the needle. Pulling from memory that it was one and not two, maybe someone else can confirm.

 

[mbarclay]

Allen ulmer told me to try raising the needle 1 position by lowering the clip 1 spot on the needle. He beleives it's a lean issue. I'm going to try it tomorrow hopefully it works out.

 

[mbarclay]

I raised the needle by moving the clip 1 position lower and its worse so im going to lower the needle and move the clip up 1 to see if that helps any.

By raising the needle I can no longer power through the hesitation.

 

[mbarclay]

no idea what to do now.....I had the needle stock 3rd position, 4th still there I then tried the 2nd and that was way way worse then I tried the 5th and that was about the same as the 4th. So Im not sure what to do now. Would adjusting the fuel screw help this? Im at 2 turns right now maybe try 2.5 turns and 4th position on the needle? Any ideas guys?

 

[grader]

try putting the clips back to stock and going up on the idle jets from 17.5 to 20.0. you can also increase the mains from 165 to 167.5. the extra fuel wont hurt anything. i run a modded airbox with 170 mains and my a/f guage says all is well.

 

[Bamboozler]

I would have thought your mid range/needle adjustments would have addressed your hesitation; it's right about that territory. Grader's advice sounds to be the right direction. Hesitation got worse when the needles where dropped, maybe you are still in a transition area between the pilots and the needles (where they are still somewhat heavily overlapped).

Do you have the throttle wide open before, during, and after this hesitation occurs, or is it happening at a partial throttle position?

 

[mbarclay]

I think I'm just going to put the stock air box back on I don't feel like messing with the carb anymore. Going to have to mess with the clutching now since the clutch kit is setup for the filters but oh well

 

[Stillsmokey]

I think I'm just going to put the stock air box back on I don't feel like messing with the carb anymore. Going to have to mess with the clutching now since the clutch kit is setup for the filters but oh well

Don't do that, between us we'll get it sorted out. I just sent an email to Holtzman Engineering to see if they have any ideas. I'm hoping my parts will arrive tomorrow and i can figure this out over the weekend.

 

[Stillsmokey]

I've spent well over an Hr looking over old posts, If i can't get this running right i'm going to try 22.5 Pilots.

 

[mbarclay]

the guy I bought the filters from said he didnt toucht he needles he just put the 165 mains in and it ran perfect with silver springs. Im going to set the needles to #4 and try the silver springs and see if that does anything