Hello fellow motor heads,
I own a 02 scrambler 400 4x4 w/hdp trail porting kit, carb, roller clutch and just finnished bolting on 4 new holeshot tires & rims.
everything went smooth eccept a little problem dialing in the throttle/oil pump cable with the new carb (had to steel some parts off the old 96)
still have some bugs left:
1. stabbing the trottle from a dead stop and the engine lags (just doesn't snap) rolling on the trottle produces better results but...
2. after clutch engagement the engine is sluggish til 20-25mph then rips hard! Is the roller clutch is shifting to quick?
[img]i/expressions/face-icon-small-mad.gif[/img]

 

Yep, that's what it sounds like. You have to run a good spring pressure on the roller setup. You should be at 6&1 on the roller if it is an HPD. Also it should be a 40-36 helix. Make sure to preload the spring 1/3 turn counterclockwise before pushing into place and installing the snapring. Other things to think about would be: Float level too low in carb causing delayed reaction in main system startup, also if it is a large roundslide carb the throttle response will be doggy. Too little a main jet could cause it, or too big a main jet would cause it. Sounds like the secondary clutch, carb problems, or possibly a bad or burnt belt.Bubba

 

sound like the clutch setup,make sure you're running a good belt,
it is belt slipping,too stiff secondary spring,i just put on a new 44-38
helix and it work great with HPD stuff,a too lean needle can cuz that too,what rpm's engament at?

 

bubba & scrambled,
The carb is a 38mm pwk (flat slide) the plug reading is perfect, belt is a new hpd kevlar...i have to ask my mechanic how he set the spring on the roller clutch but the primary kicks in higher than stock(spring came with kit).
maybe this helps answer my question; when i start to "bang donuts" the clutch engages with barely enough power to spin the rears, half way aroung it seems to shift then the power really drops off so the rears hookup and get me in a sideways weelie. if i try to continue it bogs and will not spin. does these clutches down-shift? is it possible to do donuts on an automatic?

 

I think you definitely need to stiffen the secondary spring. You still didnt say whether is was a 40-36 helix, and you can check the position of the spring yourself. It is shifting out too quick.Bubba

 

thanks guys it was my helix spring was set 2 & 3 setting it to 1 & 6 woke the puppy up!! now i can pratice my weelies[img]i/expressions/face-icon-small-happy.gif[/img]