2009 apex mtx clutching issues

[bustinlimits]

hello i put on a 2.5 ce track and bender exhaust and now anything over 3/4 throttle hits the rev limiter was wondering if anyone has any cluthing advice that would help getting this sled running at its peak potential everything stock for clutching and gearing... tops out at 130km/hr. I ride 3000ft and a few trips to the mountains every year...

 

[Got boost want snow]

When you changed to the 2.5 did you go to a smaller driver it definately sounds like you need to add weight to you primary or back off your driven 10 degrees. Your sled should have more than 130km per hour top speed with stock gearing most mtx's I think were geared for approx 160km but if you went to a smaller driver that will definately slow it down.

 

[bustinlimits]

same tooth avid drivers, it was doing it before the track change. My dealer here is no help at all... also tried the 3 and 3 setting on driven clutch also never helped. Works better on the 1 and 6 setting...

 

[modmanmike]

add weight to the primary. its easy to do.

 

[doober]

Isnt the CE a lighter track than the stock one also?

 

[Nytroman]

When you changed to the 2.5 did you go to a smaller driver it definately sounds like you need to add weight to you primary or back off your driven 10 degrees. Your sled should have more than 130km per hour top speed with stock gearing most mtx's I think were geared for approx 160km but if you went to a smaller driver that will definately slow it down.

Did you get it figured out, just picked up one for a ditch banger and over reving by a few hundred rpm. Added all the weight I had sitting in my clutching assortment box and still touches the limiter when the throttle gets squashed. will need to get heavier brass weights i guess. Running 8FS 00 with 1 brass and added two metal rivets (82g), probabaly need to go to all brass im thinking 88ish?

 

[bogeyfresh]

yamaha has a flat land kit for the sled a friend had the same issue, we bought some used weights off a nytro ,rivets were heavy, that fixed it if you look at the stock weights in that apex theres probably no rivets in some of the holes, or another route more expensive but worth every penny is look up tom hartman yamaha online, i ended up putting a 151 on my nytro xtx, and he gave me a custom clutch kit for my weight elevation etc... as well he will give you a chart with clutching setup for diff altitudes, I can still get over 100mph with that track and she pulls hard, i'm really happy just my two cents

 

[shawnmcgr]

If you were not hitting the rev limited before you made these changes I'm guessing you were not running stock gearing/clutching? At 3000ft I would expect the stock set-up to bang off the rev limited, mine did.

I don't think you really want to be going more than 130kph with a 162x2.5" track either.

Where do you want the sled to be set-up for, mtn or @ 3000ft? If you set-it up for 3000ft it'll under rev in the mtns, Likely by 1000+rpms. If you can stand being 1000rpm low for the odd trip to the mtns then set it for 3000ft and forget it. If that will annoy you then get some clutch components that are easy to adjust (Dalton primary weights and shockwave helix). There can also be a big difference between 3000ft trail riding and 3000ft powder riding.

For a set-up for 3000ft , assuming you were not hitting the rev limiter before, just add weight to the primary. The changes you have done are not huge - a bit of weight in the primary should get you where you need to be. If you what more top end speed then start with a gearing change (reduce the ration), then add weight, if you need to.

 

[ttpowersports]

I agree with the shockwave secondary, you could also try an 8bu weight (vmax-4)
Also with your set up what degree helix are you running it's seems as though u definitely need to weight the apex up they can pull 3-17.3 steels with stock weight arm, you said your running avid drivers are they smaller than your stocks?

Dalton weights are awesome u need to know what weight your running total per arm, and add at least 1.5 per test

How many km are on the sled, clutch springs, stiffer springs can also help on the primary n secondary but in order to give accurate advice. We need to know all the info, clutch build was done how long ago,

As well you can gear the mtx the same as an xtx apex , but start with the clutching from an xtx too, depending on if you want a low alt speed sled or not, I had an apex mtx put about 5000 km,s and played with a few things.

Give me a call or pm some info I would be happy to help you make the apex work for ya,,


Terry