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High revs

So changing the primary weights lowers top end rpms, will secondary spring lower cruising rpm?
 

Taken from tech section on totallyamaha, hope it can help you:

Is Clutching Magic?

Not really! First draw a large pentagram on the floor around your sled, get some candles and a virgin to sacrifice, no-no that would be a waste. Anyway, Olav Aaen's Clutch Tuning Handbook is the bible of clutch set-up. If you don't already have a copy, get one, read it, put it under your pillow at night, take it to the can with you, read it, read it, read it. Even though the clutches appear to be pretty simple, they can make a perfectly sane man sound like a babbling idiot, muttering things to himself like, wait a minute I added weight and….No, if I increase the spring rate and…..No if I…. DAMN IT !!!!! The basic idea of clutch tuning is to get the springs and flyweights in your primary (drive) clutch to bring the engine to a specific rpm PEAK using different weight and spring combinations. These combinations are endless that’s why no one person has all the answers for every condition. Then adjust the spring tension and helix ramp angles on the secondary (driven) clutch to get the shift-out you want. These combinations are also endless. The shift "characteristic" is dependent on your personal preference and riding style. The theoretical "ideal" is a slight over peak at engagement, then flat at the peak HP out all the way though the shift-out with the rpm slowly climbing above the peak HP once you're shifted all the way out into overdrive .75:1. Remember that’s theoretical. The point of this being that generalizing clutch settings is impossible. Even if I tell you exactly what I run in my sled, it's no guarantee it will work for you. Most tuners won’t give away their "trick" clutch setups that cost them dearly in lost hours of sleep, endless parts runs and tuning rides, but they may be able to point you in the right direction. Clutch tuning is the one area where you can gain a competitive advantage.

Where do I start? Focus on the primary and getting your engine rpm right. That means right at PEAK HP with steady acceleration. You'll increase or decrease the weight and or profile (where the weight is distributed in the weight itself: heel, mid, tip) of the flyweights to achieve this. Lighter weights raises the rpm heavier weights lower it. Heel = bottom end, Middle = Mid-range, and Tip = top end. Make sure you're using the same profile of weight when you make changes or you'll end up chasing your tail. Do NOT change the secondary to adjust engine rpm. I've seen too many people increase the pre-tension on their secondary to bring up their engine rpm, myself included. You are shooting yourself in the foot !!!! It decreases the efficiency of transmission of power to the track while adversely affecting the ability of the secondary to keep the shift curve flat. Once you have your rpm where you want it, you next job is to get it to shift out the way you want. That's the job of the secondary. The combination of spring and helix is what determines this. Multi-angle is what I prefer. The secondary spring directly equates to side-force on the belt. The idea is that the more side-force you have on the belt, the less efficient it is because of belt drag. Secondary pre-tension (wind) should be around 16-24ftlbs. What I try to do is get to the minimum side-force possible without slipping the belt in the secondary. Too much side-force and the clutch will back-shift too fast and put you in too low of a ratio and over rev when you stab the throttle out of a corner. Too little and it won't back-shift fast enough and it will react sluggishly (bog) and you'll loose rpm climbing hills or trying to maintain high speeds. Lastly, I’m a believer in low gearing, its less work for the clutches and engine they will run cooler. Most sled heads don’t realize that the factory gears sleds for speeds higher that the sled will ever reach. They never reach a true .75:1 ratio, also the track and engine combinations the owners and after-marketers add, won’t allow the motor to pull the tall gearing (pulls the rpm down on a long climb or high speed).

Common Pit-Falls: Clutches MUST be clean. Bushings MUST be serviceable. Springs MUST be replaced annually. Belt MUST be cleaned before break-in and every other ride (preferably) and within minimum width tolerance. If all of the following are complied with, see below. Only change ONE thing at a time. Take good notes, like snow condition, temp, elevation, terrain, what you changed and the effect it had. The primary (drive) and the secondary (driven) will directly effect each other, try not to over compensate one to "fix" the other, it’s a BALANCE you’re looking for.

Note: Remember, what works for boon docking will not work for drag racing and vise versa.

Under target rpm.

Too heavy primary (drive) weights.
Too steep secondary (driven) helix angle.
Too low tension in secondary (driven) clutch.
Too tall gearing.
Over target rpm.

Too light of primary (drive) weights.
Too high tension in secondary (driven) clutch.
Too shallow secondary (driven) helix angle.
Too low gearing.


The Original "Hammer"
 
Phazer & Phazer FX:
-Gearing: 18-41 (2.28:1)
-MPH: 81 MPH @ 11,100 engine RPM

Phazer GT:
-Gearing : 20-41 (2.05:1)
-MPH: 90 MPH @ 11,100 engine RPM

Phazer Mountain Lite:
-Gearing: 17-41 (2.41:1)
-MPH: 68 MPH @ 11,100 engine RPM

Mountain Lite uses 8 tooth drivers instead of 9 tooth, if I got it right.

Quote from another thread:
"I believe the gear reduction is actually 50/35 or 30%. Example 11,100 engine rpm = 7700 clutch rpm. So you need to reduce your calculated speeds accordingly.
Also the Mnt Phazer has 8 tooth drivers.
With these in mind - Phazer Mt Lite -MPH: 62MPH @ 11,100 engine RPM"

So I put a 1.75 inch track on my mountain lite. Don't really do any mountain riding, thinking about putting an 18 tooth top gear in it. Thoughts?
 
XTX with 1.5” has 19 top.
93.5437% of my riding is trail. Geared to a 20 couple weeks ago. Personally the taller top has increased my performance. I’m not going for “Top speed” but did want abit more for those long straight runs we have here.
By performance I mean it’s a heck of a lot smoother off/on throttle. Less backshift (front end nosing down) allow smoother aggressive corners.
I will say yesterday I was on lake powder and it sucked up the power. Still able to carve it around and play. Just not trench those big deep circles like most others.

All my throttle is 3/4 and down.
Cruising 120km/h 10,300 at 1/2 throttle.
110at 10,000 and 100 at 9800
Best part about it where the Phazer feels dead and no power left at 100 it now has some nice zip and acceleration when approaching bump or drift you need some umpf to enjoy it. :)

To me I find it perfect and according to ulmer dyno chart still utilizing max power.
Fuel mileage has gone up. I used to get 155km/tank. When I fuel up at 155 now, I have 3-4-5 litres in tank still. Depending on riding that day. That’s a significant change.
Lastly and probably the last really good thing about it is, and you’ll really notice once done, that drone we have at speed (track/exhaust/ect) has made it a much more enjoyable experience. Right down to the vibration in the bars. Adds up on those long run days.
 
Will the 19 fit on my MTX and still be able to use the same chain? Interested in selling your 19? Easy change? I had my gear case apart a few years back to replace the leaky grommet(and put in the upgraded one). Just pull the battery, outer plastic, drain case, and pull outer case?
 
Yep. Fairly easy to do. Same chain.

Time consuming part is dialing in clutches.
Be sure to do primary first. 1g I found equates to 3-400rpm. Never dial in rpm via the wrap in secondary.

I’ll give you the gear just pay the shipping. From Canada it would probably be close to $40 and I’ll bet you can probably buy one for that down there. I got lucky and found a used 20 here for 40. To buy it was 100 here. When returned they hit me with 25% restocking fee grrrrrr.
 
To be honest I didn't plan to play with the clutching. I am looking to drop the cruising RPM anyway. Maybe I should just go up one tooth, at around 9500 previously would drop me down to around 9000.
 
When I had my 2007 FX, it would hit the limiter all the time. I ended up with 4.5gram rivots in both holes on the weights. That cured the over rev.
 
I think the that’s abit low for rpm. Don’t think I would go any lower. A tooth up will definitely drop your rpm. I went up one tooth and had to add 1g to my 8DN arms. Mind you I piped at the same time. So you may just be ok regearing if you don’t want to play with weights. It’s worth a shot. Worst case senario we help you to the rpm desired. ;)
 
I know in the past small gear changes really didn’t impact the clutching rpm. Being this is the mtx, which I believe has smaller drivers. I am gonna give the 18 tooth gear a shot.
 
Good call. I think you’ll be happy. At the end of the day it’s an hour worth of work and you can always go back.
 
I've run a 17, 18, and 19 on my MTX with a 1.5" track. All 3 are just fine with the stock chain. With the YVX secondary mine gets to 1.1 overdrive pretty easy allowing a true GPS speed of 78mph @ 11,300rpm before the rpms start to climb with an 18 tooth. 19 tooth I managed 82mph gps before the rpms would start climbing (91mph on the speedo). The stock secondary didn't go past 1:1 at all for me and it would only do 68mph gps with the 17t and 76mph with a 19t so I actually have more top end geared down 1 tooth due to the YVX allowing overdrive. The Phazer makes peak torque @ 8800rpm which is usually the sweet spot for Gas mileage, trail riding mine get 18-20mpg on average.
 


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