New to the 4stroke world sidewinder mtx power mods?

[hpmaniac]

Did he have any clutching reccomendations ?
I have a hurricane 270 tune in my MTX, pulls hard on the trail, doesn't pull any harder than stock off trail.

Thought I gained some track speed but upon closer inspection the speedo reads 15ish MPH fast.

I mean if it's faster on the trail the only 2 things that could cause issues in deep snow is crappy clutching l, not enough grip on belt or poor fuel that don't like the extra load from deep snow. Yes he has clutching for his tune.
How much rpm are you running in deep snow on a hard load?

 

[hpmaniac]

Went with the clutching the dealer reccomended, they still don't have an answer for the speedo being way off. On a stock tune with my 17 MTX 162, with some refined clutching, BTX weights maxed out, and 3-3 on the secondary with stock Helix, I would see 55-58 MPH track speeds, that was with the power claw and the Challenger.

I could Punch it from a dead stop and See 40+MPH track speeds by the time the skis were at eye level....

Not quite getting the same effect now.

Get a Dalton black tan secondary spring, a 35 degree helix or a 35 39 and some Dalton weights along with a xs825 belt and dial in the weights to the rpm dave says. Probably 9100. Also check clutch alignment.

 

[Kent Smail]

I mean if it's faster on the trail the only 2 things that could cause issues in deep snow is crappy clutching l, not enough grip on belt or poor fuel that don't like the extra load from deep snow. Yes he has clutching for his tune.
How much rpm are you running in deep snow on a hard load?

Yes i would agree with the clutching being off potentially, but i know I'm not the first to have a lack of performance off trail and more specifically mountain riding. Some have went back to stock tuning, which I'm just about at.

Perhaps I will reach out to him and see if he has a recipe that gets the sled close.

Sled pulls 87-8800 @ 6-7500' elevation
Have those helixs, and the Dalton weights, but I'm pretty sure all Yamaha springs. Didn't notice much difference between the 35 or the variable.

I know the trail guys seem to shoot for 9000-9100 and seems to work well for them, but that's out of the peak torque curve which seems to matter more spinning 162 and 174 3" tracks in 3-4 feet of snow.

 

[hpmaniac]

Yes i would agree with the clutching being off potentially, but i know I'm not the first to have a lack of performance off trail and more specifically mountain riding. Some have went back to stock tuning, which I'm just about at.

Perhaps I will reach out to him and see if he has a recipe that gets the sled close.

Sled pulls 87-8800 @ 6-7500' elevation
Have those helixs, and the Dalton weights, but I'm pretty sure all Yamaha springs. Didn't notice much difference between the 35 or the variable.

I know the trail guys seem to shoot for 9000-9100 and seems to work well for them, but that's out of the peak torque curve which seems to matter more spinning 162 and 174 3" tracks in 3-4 feet of snow.

Dave has mountain specific tuning. That's what I did.

 

[hpmaniac]

If I had to guess,
In the mountains the tune is probably a little rich on fuel and maybe also pulling to much timing based on intake air temperature.
I would talk to Dave about sending a data log.
Tell him it's slow in the mountains.
A larger intercooler is probably almost a must on these if you want constant hp.
Your front clutch is a dyno. Go back to stock tune and see what rpm sled pulls in mountains.

 

[Kent Smail]

Dave has mountain specific tuning. That's what I did.

Are you saying the ECU tune itself is specific for mountains or the clutching is ?
I have read a few guys are having a little better like with the MaxSpool tunes for mountain riding.

Yamaha's factory tune is for it to be running in an ambient temp of around -20 celsius, So they are always running rich, which has me considering adding the 02 sensor and tuning...
My sled also has the CR CAI out of the hood and a 3" resonated straight pipe exhaust also made by CR so it definitely can breath properly.

The intercoolers don't do much on the sleds when mountain riding other than hold snow and add weight to the nose. If I know I have a bigger pull coming up (1-2 Minutes) I will make an effort to get all the snow out from around the intercooler. I definitely does help.

the stock tune and the clutching will pull 8700-8800 alll day long like it did for the first 1500 ish miles. If I want to ride it hard around home (3000 foot elevation) it needs another 4 grams of tip weight to keep the rpms below 9000.
Clutch offset is good, Ive had the bearing out and replaced and green loctite back together.

 

[hpmaniac]

Are you saying the ECU tune itself is specific for mountains or the clutching is ?
I have read a few guys are having a little better like with the MaxSpool tunes for mountain riding.

Yamaha's factory tune is for it to be running in an ambient temp of around -20 celsius, So they are always running rich, which has me considering adding the 02 sensor and tuning...
My sled also has the CR CAI out of the hood and a 3" resonated straight pipe exhaust also made by CR so it definitely can breath properly.

The intercoolers don't do much on the sleds when mountain riding other than hold snow and add weight to the nose. If I know I have a bigger pull coming up (1-2 Minutes) I will make an effort to get all the snow out from around the intercooler. I definitely does help.

the stock tune and the clutching will pull 8700-8800 alll day long like it did for the first 1500 ish miles. If I want to ride it hard around home (3000 foot elevation) it needs another 4 grams of tip weight to keep the rpms below 9000.
Clutch offset is good, Ive had the bearing out and replaced and green loctite back together.

Yes he has tunes max spool that are designed for mounting riding, he explained to me about how the boost is more consistent. Also he said the closed loop tuning is a game changer in the mountains, never rich never lean. Ecm is making live adjustments to fuel just like your newer car or truck.
Dave makes a intercooler that mounts where the airbox is. He said that with a fan on it is amazing for intake cooling. Overkill for 270 tune but it will keep power consistent on long pulls. Once the intake gets above a certain temp the ecm pulls timing and hp drops. Probably why people report big power increases on trail but not much different in mountains.