Belt slip, MPI Trail Turbo, Ulmer Clutch Kit

[WVTurboLTX]

I thought I would start a thread to let everyone know what I have figured out and looking to see if anyone else has the same issue. I have the MPI trail turbo with the Ulmer clutch kit and I was getting wicked belt slip all the time, even at part throttle. Belt dust was everywhere and gas mileage was terrible. The kit came set up with 4 in the toe, 0 in the middle, 3 in the heel and was told 2-6 on the spring wrap. As soon as I would go over 30 mph you could feel the belt slipping and it would never stop. The sled was sluggish and back shift was almost non existent. I started by changing the spring wrap to 2-9 on the secondary. This greatly improved back shift and got rid of most of the belt slip in the bottom and top end but still had it in the middle a little. I was also now banging the rev limiter on launches and pulling around 9000 RPM on long pulls. I then added 2 more washers in the toe. This got the RPMs back down on long pulls but it would still bang the rev limiter on launch. After that I added 2 washers to the heel. This got rid of the over rev on launch but it also dropped my RPM on the top a little and it was still slipping when you would punch it in the midrange. I then took one out of the heel and one out of the toe and moved them both to the middle. Now this thing RIPS. 8800 RPM on long pulls, no more slipping anywhere and I got 108 on GPS on a packed road in about a 1/4 mile.

So in short I am now running 5 washers in the toe, 2 in the middle and 4 on the heel with the spring wrap at 2-9. What is everyone else running once dialed in and is there anyone else that had major belt slip issues with the recommended settings?

 

[cannondale27]

I did with no turbo. Less wrap on the secondary spring solved my issues but like you had to correct rpm at the primary.

 

[TD Max]

WV,

Do you have 60Y base weights that you are running so light?

 

[Yamadog]

instead of posting here did you try to talk to Allen? I was only getting 150 miles out of a belt with Hauck's clutching (which he installed, setup and tested) since Ulmer did my sled I have over 600 miles on an 8jp and it is dead on with no dust.

 

[WVTurboLTX]

I talked to him today. He seems to think there is something funky going on with my secondary. I'm not complaining or knocking his product I was just curious what other people were ending up with after final adjustments. I have never bought a clutch kit that didn't need some tweaking after installed. It might just be that I am used to much more back shift and engine braking. The clutching on my last sled was crazy aggressive. The brakes were never used unless it was an oh #*$&@ moment. I've got it running the way I want now and am really happy with the kit. These weights are really cool how you can tune the bottom end, the mid and the top separately. I ended up leaving the secondary on 2-9 dropped the tip back to 4, left the heel with 4 and bumped the middle up to 4. No belt slip, good engine braking and it rips in the midrange in the tight trails. I'm going to just run it like this for the winter and then both clutches are going to be sent to Allen over the summer to be machined and set up by him.

 

[WVTurboLTX]

WV,

Do you have 60Y base weights that you are running so light?

yup

 

[Yamadog]

I talked to him today. He seems to think there is something funky going on with my secondary. I'm not complaining or knocking his product I was just curious what other people were ending up with after final adjustments. I have never bought a clutch kit that didn't need some tweaking after installed. It might just be that I am used to much more back shift and engine braking. The clutching on my last sled was crazy aggressive. The brakes were never used unless it was an oh #*$&@ moment. I've got it running the way I want now and am really happy with the kit. These weights are really cool how you can tune the bottom end, the mid and the top separately. I ended up leaving the secondary on 2-9 dropped the tip back to 4, left the heel with 4 and bumped the middle up to 4. No belt slip, good engine braking and it rips in the midrange in the tight trails. I'm going to just run it like this for the winter and then both clutches are going to be sent to Allen over the summer to be machined and set up by him.

No Problem but everyone is seeming to be having trouble with these clutches - Allen has always been awesome to get back to his customers. The days of spot on from Yamaha is over

 

[WVTurboLTX]

No Problem but everyone is seeming to be having trouble with these clutches - Allen has always been awesome to get back to his customers. The days of spot on from Yamaha is over

He got back to me first thing yesterday morning. I was actually in the trailer working on it when he called. Something seems to be up but I'm in the middle of a trip and got it working pretty good for now and didn't want to waste any more time tinkering on it. I'm sure he'll figure it out when I send both clutches to him this summer.

 

[cannondale27]

I believe the clutches are taxed to the max with this chassis. I have been critical of Allen and others in past but we all have been struggling with inconsistency. All you can do is get the clutching as good as possible there are other places to look for consistency. Suspension and drag are big ones.

 

[Yamadog]

Yes after 13 yrs of 4 stroke big motors this is the most trouble any model as had with the clutches

 

[stingray719]

No Problem but everyone is seeming to be having trouble with these clutches - Allen has always been awesome to get back to his customers. The days of spot on from Yamaha is over

Not everyone is having trouble with clutches. So far the only COTC I know of having issues turned out to be a bad secondary. If I missed anybody please speak up but I think that statement is accurate.

 

[Yamadog]

There are many documented problems on here from inconsistent stock clutches to spring bind....... And so on. In the old days you bought Rx or apex and 100 out of the box maybe a little weight in the arms but not all of the problems posted in here. Even guys buying aftermarket kits like ulmers are getting different results

 

[cannondale27]

Not everyone is having trouble with clutches. So far the only COTC I know of having issues turned out to be a bad secondary. If I missed anybody please speak up but I think that statement is accurate.

The trouble is speed and conditions. When someone puts $ down and says the sled does 100mph in any conditions everyday heck even 90mph everyday then all problems are solved. Maybe not clutches causing issues but nobody is sure of that.

 

[WVTurboLTX]

I ended up making one last change. I dropped back to 4 on the tip and 3 on the heel but I'm now running 4 in the middle. Pulls strong all the way through with no belt slip. I have over 900 miles on this belt with no issues. I can tell that I'm loosing efficiency running the clutches with the extra secondary tension and primary weight but it's a trade off till I can get the clutches to Allen and see what's up.