[pmk]

Anyone check for clutch binding on the sleds that won't top end? I was playing around with my clutching last week and could not get full shift, regardless of set-up it was about 1/4" from shifting out. Going to dig a little deeper, the bottom and mid pulls so hard I don't believe the motor is down on power. (F1000 w y-pipe and bullseyes.) Something has got to be holding these things back. Some run real strong and others just hit a wall around 100. Even if a guy had one that was mapped too rich on top and instead of getting 13-15 hp from the y-pipe and bullseyes only got 3-5hp it should still do better than 100. I've read the other posts about the octane and DD fluid levels and maybe they're part of the solution but I'm thinking there's more to it. With the season running down I would sure like to get it figured out before the next one starts.

 

[Oldcrow]

I'm seeing the same thing. Only reaching 99mph and overreving. Belt slip on the primary and secondary and lot of belt dust.

[attachment=63843SC00849.JPG]

[attachment=63844SC00853.JPG]

[attachment=63845SC00851.JPG]

 

[pmk]

Mine gets much closer to being shifted out, it's within a 1/4". On the picture of your primary it looks like a little belt debris was left at the top of the clutch at least once. If that's the case; could belt wear be affecting these things that much? I'm getting a lot of belt dust as well, way more than my old triple mods, almost like there's drag in the system.

 

[Kirk]

I responded to a post elsewhere in this site a while back referancing exactly what your saying about not getting a full shift out. I noticed the same thing with mine; belt riding to 1/2 inch below the top of the drive clutch. I physically checked both clutches with the springs removed to see that the belt can go to the top and it can. Part of the problem I believe is the heavy orange secondary spring; I have a D&D shift assist in my secondary (running stock helix at this point) which allowed me to pull the two plastic washers out from under the spring. Must have the shift assist to do this or it will bind the spring. The 1/2 inch shrank down to 1/4 and it gained about 5 to 7 miles per hour but it is still not as strong as it should be on top. Clutches also felt cooler. I have removed the stock weights which are to light at the tip and installed some D&D big dogs (much heavier tip weight) which should help push the belt the rest of the way hopefully and help keep the revs under control.

The other thing I am wondering about is the vibration I get in the mid range. I am starting to wonder about crank shaft run out. It would explain just about everything where top end performance is concerned especially when you consider that some are flying and some are not. Cat has in the past had run out trouble with engines from Suzuki. Cant remember which year it was but I'm sure it was on ZRT 800's back in the 90"s.

 

[pmk]

I haven't noticed any mid-range vibration. Going north tomorrow and will certainly look for it. I've only noticed a significant vibration when I stop and it holds at about 2500 rpm before idling down to 1700-1800 where its smooth again. One of the guys in another post had some broken helix mount bolts and initially thought he had a bad crank.

 

[Top Gun]

<div class='quotetop'>QUOTE (pmk @ Feb 19 2007, 10:31 AM) <{POST_SNAPBACK}></div>

I haven't noticed any mid-range vibration. Going north tomorrow and will certainly look for it. I've only noticed a significant vibration when I stop and it holds at about 2500 rpm before idling down to 1700-1800 where its smooth again. One of the guys in another post had some broken helix mount bolts and initially thought he had a bad crank.[/b]

Yeah, that was me. Im glad i mis-diagnosed it. Over 1500 miles now and it's running great.

 

[erskin]

Mine was doing the same thing, I was about 1/2" from fully shifting out, stock sled other than clutching. I am running a more aggressive helix with stock rear spring with cat orange and Dalton adjustables in the front. I had some black markings to monitor any progress while lightening up my weights. After taking some weight out, I was able to get within 1/4" of full shift out, so perhaps this is a weight issue in the primary as much as the secondary, not sure at this point. I am considering trying the shift assist, as mine does not backshift well on the trail. My sled is also not capable of going much over 100 at this point, it is disappointing. I have heard of some guys getting some better top end speeds with a stiffer front spring that has shift out pressure of 315-330, this could be worth trying as well. I'm up in the air on where to go next, any clutching gurus that can shed some light out there?

 

[pmk]

My primary is fully closed with the belt 1/4" from the top, the belt has about 700 miles on it and very little wear. I've been running 140-360 for a primary spring and 72gr weights. I think the problem is in the secondary but can't quite get to the bottom of it. Riverrat I'm glad your solution turned out to be simple and cheap.

 

[erskin]

Just curious PMK, what are you running for clutching, stock helix with cat weights or some other setup? Where did you find a spring with 140/360 rate? My belt appears to be wearing well after 500 miles as well.

 

[cmscat50]

I'd like to see a picture of the moveable sheave on the primary above.

 

[Flamin'fury]

check the little white plastic bushing in the secondary by taking out the spring and physically pushing the belt down into thwe secondary and seeing if it will go almost to the hub in the center of the sec. if the belt wont go that far down you need to trim a little off the end to let it go into the sec further. also these primarys need MORE tip weight not less these things are way overreving in stock form.

 

[Oldcrow]

<div class='quotetop'>QUOTE (cmscat50 @ Feb 19 2007, 03:39 PM) <{POST_SNAPBACK}></div>

I'd like to see a picture of the moveable sheave on the primary above.[/b]

Same thing

[attachment=63954SC00856.JPG]

 

[Oldcrow]

<div class='quotetop'>QUOTE (Oldcrow @ Feb 19 2007, 06:00 PM) <{POST_SNAPBACK}></div>

<div class='quotetop'>QUOTE (cmscat50 @ Feb 19 2007, 03:39 PM) <{POST_SNAPBACK}>

I'd like to see a picture of the moveable sheave on the primary above.[/b]

Same thing

[attachment=63954SC00856.JPG]
[/b][/quote]

I take that back.
The movable shows slippage just like the stationary but in a differant location. I think I have vertical alignment problems. I'm making some tools to verify this.

 

[pmk]

<div class='quotetop'>QUOTE (erskin @ Feb 19 2007, 03:26 PM) <{POST_SNAPBACK}></div>

Just curious PMK, what are you running for clutching, stock helix with cat weights or some other setup? Where did you find a spring with 140/360 rate? My belt appears to be wearing well after 500 miles as well.[/b]

The 140/360 primary spring is from Goodwin, I also have their 140/310 and a Polaris Almond which is 140/330. A 50/36 and a 50/38 helix with either a 235/335 or 215/315 spring as well as the stock stuff. With the combos I was running I was unable to get any decent top end and no consistency from day to day. I'm copying some of the set-ups that were on HCS this next time around with the exception that my starting helix angle is 50 instead of 48. If I can't get these combos to work I'm going to try a 48/38 and a 46/38 helix. I've found 72gr weights work pretty well, on a couple combos I had to use two 70s and two 72s to keep from pulling the r's down too far. I also have 73gr weights which so far have tended to pull the r's down too much in every combo I've tried. I going north again tomorrow and I 'm starting with 72gr weights and the Polaris almond 140/330 spring. A D&D shift assist in the secondary and a 50/38 helix wit a 215/315 spring. There's a good thread on HCS: http://www.hardcoresledder.com/forums/inde...howtopic=216808 It sounds as if a couple guys found very similar set-ups that run hard and are consistent. I have the D&D y-pipe and bullseyes but haven't had the remap yet.

 

[pmk]

<div class='quotetop'>QUOTE (Flamin @ Feb 19 2007, 03:47 PM) <{POST_SNAPBACK}></div>

check the little white plastic bushing in the secondary by taking out the spring and physically pushing the belt down into thwe secondary and seeing if it will go almost to the hub in the center of the sec. if the belt wont go that far down you need to trim a little off the end to let it go into the sec further. also these primarys need MORE tip weight not less these things are way overreving in stock form.[/b]

I did what you're suggesting last night and the belt went pretty deep. I toyed with the idea of trimming the plastic stop sleeve but was afraid the belt would begin to hang up in the flats where the sheaves go from being tapered to being parallel to the shaft. I'll order a new stop sleeve and then trim the original so if the belt begins to hang I won't have to wait on a part. My primary physically closes, metal to metal, and will not allow the belt to travel the last 1/4" to the top. Maybe a little machining is in order.

 

[cmscat50]

You primary shows what I thought it would. MORE rubber on the moveable. That's an offset issue. Secondary needs to go in toward the DD. Not sure how many shims you have behind the clutch now, but I believe you need a minimum of .120 to clear the DD....others may need to verify that.