Tomar 3 Disks set up For Indoor oval

ROTAX10

Member
tomar clutch.jpg
Hey clutch experts. Not sue If I should Post his here or in the clutch section. I picked up a dirt kart with a Tomar 3 disk. It appears to be an older version of the Td 23. The guys at Quarter Master were no help as they can't even get ahold of their own tech guy. The clutch came off a kt100 and will be going back onto a different kt with the same jackshaft set up. The guy was around 190lbs. Im 125lbs and running approximately a 25hp KT in the 10200-10500 rpm range. And will be running Hoosier 12/9/6 treaded D30s if that makes a difference. Approximately 11.5 final gear ratio. My question is clutch set up for my weight and I guess mores specifically spring height. Also the track surface is way hooked up tight corners.
 

flattop1

Dawg 89
That seems kinda low for rpm .
That where we had the clutch come in .
Is it a pipe engine ?
Builder didn't advise on stall speed ?
 

ROTAX10

Member
That seems kinda low for rpm .
That where we had the clutch come in .
Is it a pipe engine ?
Builder didn't advise on stall speed ?
Thanks for the reply your the first out of many posts Ive put out today It is a pipe engine. I called Quater Master which is Tomer, They had no info for me and said its extremely hard to get a hold of their tech Guy. lol
 

ROTAX10

Member
Thanks for the reply your the first out of many posts Ive put out today It is a pipe engine. I called Quater Master which is Tomer, They had no info for me and said its extremely hard to get a hold of their tech Guy. lol

That seems kinda low for rpm .
That where we had the clutch come in .
Is it a pipe engine ?
Builder didn't advise on stall speed ?
Heres a like to a you tube video of the track and the first race is the class im running KT light.
 
Last edited:

nobozos

Member
Flattop1 is spot on, that Yami will want the clutch at 10200 or more depending on the pipe. With a track that small you should never come off the pipe. That thing won't start to sing until you see 13,500. later Chuck.
 

ROTAX10

Member
Flattop1 is spot on, that Yami will want the clutch at 10200 or more depending on the pipe. With a track that small you should never come off the pipe. That thing won't start to sing until you see 13,500. later Chuck.
1634878532553.jpeg

Does this seem right! Engine builder was Collins Or CRE one of the best in the country!
 
That is exactly right.
The key is the jackshaft ratio.

~3800 is pretty typical for a pipe Yamaha through a 2.71 ratio.

Tomar support is all but non-existent (or at least it has been since Quarter Master bought them out, and has only gotten worse since the 'Rona.)
Great clutches - we still work on quite a few of them each year.

-----
🏁Thanks and God bless,
Brian Carlson
Carlson Racing Engines
Vector Cutz
www.CarlsonMotorsports.com
Carlson Motorsports on Facebook
32 years of service to the karting industry ~ 1Cor 9:24
Linden, IN
765-339-4407
bcarlson@CarlsonMotorsports.com
 

ROTAX10

Member
That is exactly right.
The key is the jackshaft ratio.

~3800 is pretty typical for a pipe Yamaha through a 2.71 ratio.

Tomar support is all but non-existent (or at least it has been since Quarter Master bought them out, and has only gotten worse since the 'Rona.)
Great clutches - we still work on quite a few of them each year.

-----
🏁Thanks and God bless,
Brian Carlson
Carlson Racing Engines
Vector Cutz
www.CarlsonMotorsports.com
Carlson Motorsports on Facebook
32 years of service to the karting industry ~ 1Cor 9:24
Linden, IN
765-339-4407
bcarlson@CarlsonMotorsports.com
Awesome thanks for your response I really appreciate it. Its the most helpful one yet. What are your thoughts on the bolts through the weights. Also I noticed all 6 allens were used to bolt the clutch together over the 3 they come set up with. The previous driver was around 200lbs im 125lbs. I've been told take every other bolt out of the weights. Im assuming the extra allens just add more rotating mass which in my book is smoother power to the ground but not as hard of a hit? And last This is a steel basket and is just showing signs of a little wear. Im going to file the minor notches smooth for this weekend. Quatar master could not even tell me if the new baskets were Alu or steel if fact they couldn't even tell me anything about this clutch as it looks nothing like the newer ones. Its it even a TD23? Thanks for taking the time Dan
1634929523299.jpeg


tomar-clutch-jpg.18208
 

flattop1

Dawg 89
Your going to want it too come in at 10,500 rpm .
Put it on , then see where its at .
Adjust from there .
Less weight more rpm .
More spring pressue more rpm .
And vice versa .
 

ROTAX10

Member
Awesome thanks for your response I really appreciate it. Its the most helpful one yet. What are your thoughts on the bolts through the weights. Also I noticed all 6 allens were used to bolt the clutch together over the 3 they come set up with. The previous driver was around 200lbs im 125lbs. I've been told take every other bolt out of the weights. Im assuming the extra allens just add more rotating mass which in my book is smoother power to the ground but not as hard of a hit? And last This is a steel basket and is just showing signs of a little wear. Im going to file the minor notches smooth for this weekend. Quatar master could not even tell me if the new baskets were Alu or steel if fact they couldn't even tell me anything about this clutch as it looks nothing like the newer ones. Its it even a TD23? Thanks for taking the time DanView attachment 18306

tomar-clutch-jpg.18208

That is exactly right.
The key is the jackshaft ratio.

~3800 is pretty typical for a pipe Yamaha through a 2.71 ratio.

Tomar support is all but non-existent (or at least it has been since Quarter Master bought them out, and has only gotten worse since the 'Rona.)
Great clutches - we still work on quite a few of them each year.

-----
🏁Thanks and God bless,
Brian Carlson
Carlson Racing Engines
Vector Cutz
www.CarlsonMotorsports.com
Carlson Motorsports on Facebook
32 years of service to the karting industry ~ 1Cor 9:24
Linden, IN
765-339-4407
bcarlson@CarlsonMotorsports.com
I was just on Bullys website and saw they use a gold steel basket that looks Identical to mine, So Im guessing I have a Bully basket if thats possible and they interchange?
bullythreedisk.jpg
 

nobozos

Member
Brian and Flattop1 are on the money. If you take the 2.71x 3800 ( Jack shaft rpm) you will get 10,298 so either is correct. Without a jack shaft for my enduro with a axle clutch I set mine between 10,300- 10,600 depending on the weather but that's for a 400+ weight class. later Chuck.
 
Couple of general comments:

Unlike your wife or girlfriend;
Your clutch does not know how much you weigh.
It doesn't even care.
It DOES react to centrifugal weight and a specific rpm to engage at.
You want the clutch to engage at (or very near) peak torque for your engine.
The guys that are running 400 - 450# may want their clutch to engage slightly higher rpm, because when the clutch fully engages, it will pull down a bit more than with a lighter car, but that's not how any clutches are set on a dyno. They are set for a specific rpm.
The end user can fine tune to their personal liking after that.


-----
🏁Thanks and God bless,
Brian Carlson
Carlson Racing Engines
Vector Cutz
www.CarlsonMotorsports.com
Carlson Motorsports on Facebook
32 years of service to the karting industry ~ 1Cor 9:24
Linden, IN
765-339-4407
bcarlson@CarlsonMotorsports.com
 
Awesome thanks for your response I really appreciate it. Its the most helpful one yet. What are your thoughts on the bolts through the weights. Also I noticed all 6 allens were used to bolt the clutch together over the 3 they come set up with. The previous driver was around 200lbs im 125lbs. I've been told take every other bolt out of the weights. Im assuming the extra allens just add more rotating mass which in my book is smoother power to the ground but not as hard of a hit? And last This is a steel basket and is just showing signs of a little wear. Im going to file the minor notches smooth for this weekend. Quatar master could not even tell me if the new baskets were Alu or steel if fact they couldn't even tell me anything about this clutch as it looks nothing like the newer ones. Its it even a TD23? Thanks for taking the time DanView attachment 18306

tomar-clutch-jpg.18208
Keep the 6 bolts in there -- make sure they stay tight. You might consider using some Blue Loctite on the threads as bigger HP applications and jackshafts seem to take their toll on bolts vibrating loose.
Now, for the weight bolts:
Taking every other weight bolt out will raise the engagement rpm.
There is no way that we can tell you if that is correct or not without knowing if it engaged correctly prior to this, or at what rpm it engages currently.
I doubt that you want to raise the engagement rpm, but again, without more info that's going to be hard to determine.
Taking every other weight bolt out will also soften the engagement. More weight keeps the clutch engaged (limits slipping) at higher rpm when it should be fully locked up 1:1.
 

Bradley71

Member
Keep the 6 bolts in there -- make sure they stay tight. You might consider using some Blue Loctite on the threads as bigger HP applications and jackshafts seem to take their toll on bolts vibrating loose.
Now, for the weight bolts:
Taking every other weight bolt out will raise the engagement rpm.
There is no way that we can tell you if that is correct or not without knowing if it engaged correctly prior to this, or at what rpm it engages currently.
I doubt that you want to raise the engagement rpm, but again, without more info that's going to be hard to determine.
Taking every other weight bolt out will also soften the engagement. More weight keeps the clutch engaged (limits slipping) at higher rpm when it should be fully locked up 1:1.
Over the last several yrs i have been running a totally different clutch setup than what 2-stroke pipe manufacturers call for.ill probably catch hell for my post but i use to run the 10,200-10,500 stall but i decided to think outside the box.i have a couple reasons for it.i run in 8500-9000 range for the fact of its easier on clutch during cautions and on slow restarts i can pull away.my lap times didnt change but the starts are so much more smooth,it keeps the back tires under u and moving you forward.and there is no more reving the heck out of the motor on cautions building heat in the clutch.hell at 8500 rpm my 116 cc open prob makes 25 hp😂🤷🏻‍♂️That kart flat rolls out when u hammer down.😂😂i actually learned the trick riding dirt bikes,instead of running second gear trying get the front tire over a log use 3rd and no clutch,it will grip a thousand times better.
 

spincycle

Site Supporter
Thanks everyone for sharing, I'm in the process of getting a 131 Sudam up and running, when I bought it, it had a clutch on the jackshaft, totally my bad but I ran the engine last weekend without checking stall/set up and ended up smoking it, so I'm now going back to jackshaft/ clutch set up 101 and have picked up alot of great info from this thread...😉👍
 
Top