Tweaking Ulmer Clutching

[thetruck454]

First off let me say that when I typically ride I don't just mash the go flipper, I like to use the torque of this motor to move me. I like to ease in and out of the throttle (rapidly but still not on/off) and use the engine braking so the brake is more for those oh S#$% situations. I do ride at pretty good clip, but I tend to ride with some safety.

With that said after installing Ulmers cluthcing I've got this weird thing going on with clutching. The sled doesn't feel as jumpy at initial take off, but I'm going to assume thats due to the shift in power band from the header. Around 30-55mph (or under 6800 rpms) the sled feels all mushy. I give it more throttle and it almost feels like a high stall converter because the engine revs more but I don't feel it accelerating. When i get up to 60+ (7000rpms+) this thing just goes. Its like a rocket ship at those higher speeds even with gradual inputs of the throttle. The problem is that most of my riding is in that 30-50 mph range.

Top speed with is about 103-104 at 9050 rpms. Other times I only saw in the high 90's at 8700rpm, but it was in the upper 20's that day and the snow was loose/warm.

Is this due to the new secondary helix angle? or can I tune this our by changing the weights on the primary. My initial thought would be to add more weight in the middle position on the pirmary to cause it to not shift out as much, but I don't know enough about how the clutches work to figure out what to play with. I haven't gotten a chance to talk to Allen yet, but I hope to this week.

Any input would be appreciated, Thanks

 

[TurboTime]

First off let me say that when I typically ride I don't just mash the go flipper, I like to use the torque of this motor to move me. I like to ease in and out of the throttle (rapidly but still not on/off) and use the engine braking so the brake is more for those oh S#$% situations. I do ride at pretty good clip, but I tend to ride with some safety.

With that said after installing Ulmers cluthcing I've got this weird thing going on with clutching. The sled doesn't feel as jumpy at initial take off, but I'm going to assume thats due to the shift in power band from the header. Around 30-55mph (or under 6800 rpms) the sled feels all mushy. I give it more throttle and it almost feels like a high stall converter because the engine revs more but I don't feel it accelerating. When i get up to 60+ (7000rpms+) this thing just goes. Its like a rocket ship at those higher speeds even with gradual inputs of the throttle. The problem is that most of my riding is in that 30-50 mph range.

Top speed with is about 103-104 at 9050 rpms. Other times I only saw in the high 90's at 8700rpm, but it was in the upper 20's that day and the snow was loose/warm.

Is this due to the new secondary helix angle? or can I tune this our by changing the weights on the primary. My initial thought would be to add more weight in the middle position on the pirmary to cause it to not shift out as much, but I don't know enough about how the clutches work to figure out what to play with. I haven't gotten a chance to talk to Allen yet, but I hope to this week.

Any input would be appreciated, Thanks

You could try to back your weight down to the heal, otherwise it sounds more like a helix issue. Also, do you have the secondary in the 0-6 position?

 

[bottlerocket]

Belt slip? RPMs are to high at 9050 so you would need another washer in the heel but I would consult Allen.

 

[mewaschuk]

I get my Ulmer kit to rev over 8400...

 

[thetruck454]

You could try to back your weight down to the heal, otherwise it sounds more like a helix issue. Also, do you have the secondary in the 0-6 position?

I think its in thr 1-6 position

Belt slip? RPMs are to high at 9050 so you would need another washer in the heel but I would consult Allen.

It could be belt slip, I do have grooves on the primary down by the haft

 

[bottlerocket]

Thats normal to have a groove at the top of where the belts sets at engagement from what Im told but you will smell it or clutches will be very hot after a few hard pulls.

 

[BADSLED]

Contact Ulmer racing and they can assist and advise on addressing your concerns. There is something wrong with your sled if it's feeling "mushy" and lacks acceleration.

 

[Daranello]

I took all my weight out of the mid and tip and it was snappy and fast. Rpm were a tad high on top at 9200-9300
Add mid and tip and she got mussy like you said. I'm going to try just taking out the tip weight next run.

Btw my sled just ran 114mph 9060 rpm with the weights in. But I know she's got more in her. If I get the RPMs upto 9200 I'm sureill hit my 116mph

 

[#2gunsmoke]

i wish i could get that rpm out of mine....i can only hit 101.. and she doesnt brake 9 on a lng straight at wot. i think the weight is to much.. and maybe thats y i can only hit 87.2 in 660 and 94.1 in 800. wish i could rev this thing more.. its like a naughty girl u need to spank her to make it that much more enjoyable.. and at 8800 she is just getn tickled, 9200 would b a nice spank....

 

[thetruck454]

Allen said to add one washer to the heel. I'll try that this weekend and see how it goes.
How does each position effect the shifting of the primary?

 

[RIKMAN]

Heel= take off
Center= midrange
tip= top end

 

[thetruck454]

That much I figured.

Say I add weight in the center, does that effect mid range on the slow roll on throttle as well as if I punch it? Or is the rpm when punching it more effected by the secondary spring/helix? Also how does the primary spring come into play? I assume it just opposes the weights shifting the clutch in?