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help with clutch improvement threw drilling
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Posted by: reed19889

i seen an article before about taking your stock clutch and drilling it to lighten it up for better performance now all of a sudden i cant find it can any one help we have a 08 apex 90 long travel thanks

Posted by: marsrace2

you just drill holes in the clutch shoes to lighten them up, however the Apex you have already has a light weight clutch.

Posted by: reed19889

i believe there is certain patttern and drill bit you are suppose to use

Posted by: marsrace2

it is just a matter of how many holes and how much weight you want to take out.

Posted by: reed19889

what is the average what does it actualy do for performance so the lighter it is the more poower is it power on the take off or top end

Posted by: tgcheeseman

What some people say is that yes you can gain by a lighter rear clutch first of all mine weighs 435 grams. If you lighten the rear clutch you gain more stall speed and gain from less rotating mass of the clutch. You get better hole shots and more mph on the top. Less power to turn the heavy rear clutch..IMO. Hetricks have what your looking for the way to do it. The size drill bits and how many holes. Hope this helps you out.

Posted by: ecmini1

The real purpose of lightening is to get the machine to take off near the power curve. What some people call "in the pipe" A 2 stroke has a power curve and your trying to get the bike to be near that curve for the best take off "holeshot" lighten to much the stall becomes higher and you lose some of the quads drivablity. Need to find the happy medium between the front variator and rear clutch.

try 4.5g-5.0g rollers, 2000 clutch springs and 2000 shift spring is the average for motor cross. Pipe and carb combo make a diffrence aswell. But this will get you in the park.

Posted by: tgcheeseman

I believe this is what I said, What he said is the same as me just in a different way. I would say try the 1500 ZTR and 2000 clutch springs and if on a 90 use 4.75 to 5.0 not the 4.5 as you will loose and it will rev way up and not have anything on the take off and no speed. As a matter of fact take off your clutch cover and mark the vaiator with a marker and see where your belt rises to you want the marks all off or as close to all off as you can try this and let me know and ill walk you threw the rest.

Posted by: rider1234

how does belt length affect stall?

Posted by: ecmini1

Bulldog,

Wow that was well put.

Your right to many unknown factors to guess at it.

Posted by: reed19889

the bike has an sms pipe v force reeds 4.5 gram rollers 1500 rpm spring and red clutch springs malossi kevlar belt i will get numbers and submit them in a little bit ported engine and 28 mm carb besides that its stock trying to get in touch with local shops looking to get dyno done i live in pa zip 16666 so any help would be great thanks to everyone i can use evrything everyone sends me

Posted by: hotquads1

after reading your set-up , you may can just change to 4.25 rollers and achieve what you are seeking. ported cyl and SMS pipe are gonna like RPM, try the lighter rollers and let us know.
marc

Posted by: reed19889

everone was saying to go to a bigger roller not smaller and how about size of clutch spring

Posted by: bulldogfallon

quote:
Originally posted by reed19889
everone was saying to go to a bigger roller not smaller and how about size of clutch spring

I wouldn't disregard anything Marc recomends

"Everyone" had no idea what you were running and made general recomendations.

The more rpms you turn generally the lighter the roller weight you can run

Posted by: reed19889

the belt is malossi kelar belt # 6112742 does that sound like the right belt for the set up or to long

Posted by: riding4fun

That belt is fine.

Posted by: reed19889

so i should switch to a 2000 spring and 4.25 rollers

Posted by: bulldogfallon

Brand of the torque spring is also critical

Same rated spring from different brands are not even close in strength

Be careful to listen to too many options at once

I would pick one source and stick with them...

Posted by: reed19889

i usually use the koso spring i was thinking about using the ztr one but which one do you use or prefer to recommend i also use koso rollers

Posted by: bulldogfallon

Both are quality brands that we use.

What is that you are trying to get from this post.

I know your questioned asked about lightening a clutch, but what is it that really need to know.

Are you checking to see if your set up is good in our opinion or are you having an issue that needs to fixed.

Just wanted to make sure we can try to get you the info you need.

Posted by: reed19889

i am just trying to get some knowledge andset see what set up works best for everyone so far like tr ial and error i was just trying to skip the items that dont work and i appreciate everyones help in everything

Posted by: bulldogfallon

If you can get your clutch to engage where the engines makes power and still have low gear and belt travel you are ahead of most.

Posted by: reed19889

i marked the variator with the black marker and let the boy ride it around a little and then i checked the variator there was a 1/4 inch left on variator so is that good or do i need to lower the roller weight or spring also i have the red springs on the clutch it self any help would be great thanks

Posted by: ecmini1

Your close but go heavier to get more from the variator. How is the bottom end with your curent set up?