No power from 3800-6000rpm at WOT

[F500-92]

2 weeks til our event.  I had a couple friends over yesterday to do some wrenching and testing despite the lack of snow. 

Anyways, we were messing around doing some "grass drags" and my sled is lacking out of the hole.   I have very little power from 3800 to about 6000 rpm and then it takes off. 

I have P85 primary on it and I have it engaging exactly at 3800. 

I'm believe its rich because If I give it a squirt of primer or a short flip of the choke, it kills it even more.   

Thinking more about it today, Is this an air screw adjustment? I have it at 2 turns out, went to 2.5 and it was about the same.   

Everywhere else the sled is awesome and now I just don't want to embarass myself in the drag event like I did this weekend.  Luckily there was just 3 others to give me crap.  Not 25 people. 

Video for lulz.
https://drive.google.com/file/d/1DFACfkTWoQ6qstyU_oSVywCQp5eQ_wrq/view?usp=sharing

[gixxer6]

That doesn't look too far off from normal Invader performance.  Remember, it is an old piston port 440.  No rotary, reed, or exhaust valves to help the low end power.  For drag racing 3800 is way too low of an engagement.  Try upping it to 4800. 

[kawhead]

4800 and a good belt, no slop

[jimvw57]

Might want to try 340 gears since you probably won't hit top end before running out of track/

[F500-92]

Drag isn't the only event.  I'm going to shoot for 4300 to be a bit more well rounded.

Played around with the air screws a bit more. Does this sound about right for a stock sled?  Video is dark on purpose.  The competition doesn't know what I'm bringing    and I shared it with them also.

https://youtu.be/2wcUNS4Aa4E

[F500-92]

Swapped springs out for one that has about 25lb higher starting rate, same finishing rate and kept the same 56 gram weights.     Engagement is about 4400 now.  Too late to test.  I'll save that for tomorrow.

[gixxer6]

Drag isn't the only event.  I'm going to shoot for 4300 to be a bit more well rounded.

Played around with the air screws a bit more. Does this sound about right for a stock sled?  Video is dark on purpose.  The competition doesn't know what I'm bringing    and I shared it with them also.

https://youtu.be/2wcUNS4Aa4E

Sounds right to me.

[F500-92]

closer.  struggling with the balance of engagement RPM and Max RPM....  https://www.youtube.com/watch?v=A46XGlPZICM&feature=youtu.be

[Mark Hill]

  How much belt deflection do you have in your primary clutch?
  Also your belt should be about an 1/8 or a little more above the top
  Of your secondary clutch before engagement. Might should check choke plungers
   to make sure they are seating all the way , fuel may be going around them and
  Causing a rich condition . What size helix are you running ?
  You still have many things you could try . Test test test wins races

[F500-92]

Very little deflection.  Belt was dragging when it warmed up a bit.  its fine now.  I couldn't get the jackshaft any further forward.
Belt is sitting a little over 1/8".  .142" to be exact.
Good call on the choke plungers.  I know I have them set correctly.  didn't think about them seating all the way.  I have a couple new spares I'll throw in... I'm assuming they're the same as the VM38's.
Totally stock secondary.

[Mark Hill]

    I’m thinking your belt might be to wide . Check the
    Distance between belt and sheave on your primary
   Clutch . This should be around 3/16 of an inch . If it’s tight to
   to the sheave it will create a bog on lower end and will take
   longer to shift out . Also your clutch would run warmer .
   Simple fix would be to find a belt that fit better ( if your lucky)
   or shim the spider on your clutch which sometimes is hard
   to get apart . I have also seen guys with your issues have a track or
   chain to tight and even to many studs bogging the motor until after take
   off . Good luck !