I've installed a fett brothers excellerator clutch kit and can't get the heavy hitters dialed in. I have done quit a few other mods also but it seems like the sled pulls real hard to about 70 or 80 mph then it just falls on its face. Was on Gogebic earlier this year would pull most everybody out of the hole then they would go by hard at about 75 mph. Sled what run 101 on digital speedo but it took a long time to get there.

Do a run and then feel your clutches. Heat in the primary or secondary??

Heat seems to be in the primary

Next question then. Is there more burnt rubber on the outter or inner sheave?

First thing is to pull all the shims out from behind the secondary and only put in one .030 one. Soulds crazzy but will cool the clutches off by 50% just doing this.

If your running the 036 belt put more tip weight in the end less in the mid nothing in the rear allen set.

If your running the 044 run most in the mid and a bit in the rear allen set nothing in the tip.

Both respond very very good moving the secondary in. If you find that the secondary is loose moving in and out after the bolt is tight check if the washer is not cupped out on the shorter bolt. If it is....... just flip it over and it will work tightening the secondary on snug.

The best set up is the up-dated F7 bolt and ajuster. IF your running the black dimond ajuster you will need to washer up the bolt to make sure the secondary dos not move in and out after.

I am running with out any washers with the secondary right up against the seal/bearing. It just seem to go faster and faster the more shims I took out. You may need to tap tap the foot well brace with a block of wood because as you get more shift the back of the secondary will rub there.

The interesting thing is that if you take all the springs out of the clutches run them through their shift you will see there is 1.375" shift. Meaning the primary will move in 1.375"s with the belt and in the secondary will open 1.375"s. If you mark how much your rollers are moving on the helix angle you will find that your only getting 1.1 to 1.125" of shift. Well by moving the secondary in .125"s I was getting that added to my shift with out any other change. This was telling me that the off set was not enuff loading the secondary enuff trying to pull into the over drive. So running a higher start rate and lower finish rate on the secondary spring loaded the secondary later into the shift more twisting the belt flat agian. Make sence?????????????

The belt twists under load. You off set this by moving the secondary in. BUT after the sled is up to speed low load on the secondary/belt the old clutch would move out keeping the belt flat. The DDrive you cann't move the clutch out so the off set is not correct at light load. Loading it more at the top of the shift is the only way to keep getting more MPH and keeping the twist on the belt.

Once your under stand this your DDrive sled will be faster than an old'er sled with a floating clutch. Funny thing is alot of people don't under stand this and this is why there is the 80-90mph wall the belt is flatter in the secondary will very poor off set slipping the belt like mad.

Don.

thanks will try that tonight. I'm running the orange secondary spring with the shift assist right now maybe thinking about putting the spring that came with the fett brothers kit back in with the shift assist.

I'm running the aluminum deflection adjuster That goes together with the tss clutch tool. Was possibly thinking about gearing up a little maybe like the f-6 or a little higher, but would like to get the clutches dailed in first. May not be necessary to gear up

Na don't gear up if anything when you have time go to the ten tooth drivers. They are bigger and will gear up some and let the track turn over the drivers better too. If you cann't get 117mph out of the 60/60 gears your not holding the belt in the secondary. With the 10" a ten tooth drivers the crossfire should shift .125" from the top of the 8.5" primary. This pic the sled was clocked at 116mph with ten tooth drivers 60/60 gears.

Dunno, can the motor be moved like on the older models not dd. to set the offset? I tried the shim removal and gained 3mph I could only get 103 on ice ,now 106. I put the shims back in and went back to 103. excellant tuning!! I have 06 700xf. I did some of your clutch suggestions the white spacer. I got full shift now, used to miss top of clutch by half of a inch. I also went to the 10 tooth drivers and gained 10mph and still have super acceleration. thanks for all your info!!!

Thor 9 did you cut some off the white spacer or what are you talking about the white spacer? I'm heading out to the shop after supper to work on my clutching didn't have a chance to work on it last night.

I took 60thosanths of the white spacer, the belt still has room to move in, somwhere dunno has a good write up on this and other tricks to get full shift and into over drive. take your spring out of the secondary and put the belt in as if it was in full (open) shift, you will see that the spacer stops the clutch from opening any more. by trimming the spacer it will open it up more making the belt go deeper. But you haveto make sure you don't bottom out the belt in the secondary. There's room. When the belt gets pulled deeper the belt moves up in the primary. I had about 1/2 inch from top ,now I have about 1/16 in. The shim removal also works like mentioned above. Originally I could only get qbout 90mph and now 106. I have the 60/60 gears, the 10 t drivers and the shim removal, Primary has d&d set up orange spring, 73gr big dog weights and a orange cat spring (07) in secondary, with d&d shift assist.

Thor9, what belt are you running? stock cat, or the xs801? If I only put the .030 shim in behide the secondary It won't hit the head of the helix bolts on the gear case would it, at full shift out?

The sec. spring will reach full compression, before the white stopper does anything...The clutches are much cooler without the washers behind secondary.

I'm running the 044, when I did cut the white spacer, I saw belt take up to within 1/8in from top of primary from almost 3/4in. I did also put the shift assest in to, could that have done it (maybe spring bind was stopping it?)

I got the same problem, 85is max speed on mine, the belt is a 1/2 inch shy of the top of the primary, 06 xf7 all stock, I took out the washers behind secondary though. Mine also doesnt have 60/60 gearing mine is 65/55 5 pinion is that hurting my top speed?? yellow spring in prim. dark green sec. Any help would be greatly appreciated.

I'd bet you are slipping the belt in the secondary.

what should I do about this problem? Order a clutch Kit or what? what can u get for top spd

I have the shift assist installed and I think thats whats doing the trick. I markered up my secondary sheves and went for a spin after I checked it there were no black marks left.

who makes the shift assist kit?

D&D, its pretty cheap too. Another thing I noticed was that the white secondary adjuster would always back its self off after I would turn it in, NOW with the shift assist no binding, no adjuster backing off. I think it helps.

Stupid question time - what is a 10 tooth driver?

Click to view attachment

It's the # of teeth on the driveshaft. Stock is 9. You can see from the pic above.

How does removing shims behind sec. affect shift of sec. Sounds like to me you are starting out at a different offset when you remove shims behind sec.Possibly making the belt not line up straight at full speed prematurely wearing out belt. I guess your just making the belt tighter when you remove shims which equals more speed.

Where are these shims located on the DD, I dont see any at all when I take the secondary off.

This is where the shims are Located.
I tryed just leaving the .030 shim, but when I tighten up the short bolt the secondary moves in and out. How do you get rid of the slop using the stock small bolt??? I agree with catlady, this seems to make your belt not line up straight. You would think you would wear your belt out quicker? I know you say it keeps you clutches cooler but anyone have more info on this?

You dont

When removing shims , you will have to get Cats updated aluminum adjuster and long bolt or BD aluminum adjuster and long bolt to remove the slop created

Leave a minumum , one .060 shim behind secondary - Or else on fullshiftout the moveable sheave on secondary will start to rub into the aluminum frame bracket behind secondary

Of course the belt will not look straight just sitting there

Look at your primary clutch in relation to your frame - The front of the primary clutch should be closer then the rear - When you put the engine under load(Torque)the rear of the primary clutch moves inward towards the frame - Elevate your track , and run the sled up and watch your primary clutch/belt move inward and back with the torque of the motor and you will figure everything out

Thats why Parallalism is just as important as Offset

You guys that are picking up the mph, how far are you running the sleds to get those increases? Mine seems to hit that 90 mph wall too where it just stops pulling, about then a firecat starts to walk away.

Scott, mine was hitting at 90mph with a .060 in there. Got the hammer out and now even with .030 it doesn't hit at FULL shift. 110 on the speedo