Can anyone tell me why this clutch is crackin here

[rat4020]

This pict is off my buds clutch not an Apex but Ive been letting him use my spare for my Apex the past three winters and he called me on sunday and said the same thing happend to the primary I loaned him WTF ?
Any Ideas ..

I was lookin around on Ebay on sunday and saw at least three adds selling clutches with the same problem as this one and the real Kicker was those morons where selling them as " In Good cond usable "

 

[Turbotom22]

Rat4020 I have a question for you. I am putting a 2004 Yamaha RX1 engine in a mini buggy and am using the primary, secondary and chain case out of the sled. I am about ready to start test driving and was wondering about clutching. I talked to a guy that ran that engine years ago he remembered that he put lighter weights in the primary but could not remember which weights. Do you have any suggestions?

 

[kinger]

Fuzzy picture I can't see anything. The only time I cracked my clutch was from too much heat, my clutch temps were off with a poorly designed clutch kit. Once Ulmer fixed it they were cool to the touch and supporting 250+ hp no cracks since then.

 

[maim]

never broke one like that. looks like something dropped on it to break it. i always crack mine in the clutch faces from belt heat/wear.

 

[mbarryracing]

There is no stress there from operation, someone pried on it for some reason.

 

[sgauthier]

as mentioned above. never seen one break like that in that area unless something dropped on it.

 

[74Nitro]

The only time I've seen this type of damage on an Apex clutch was from the sled being in an accident like the front suspension shoved into it, or the machine landed on something which damaged the clutch.

 

[ClutchMaster]

View attachment 154067
Rat4020 I have a question for you. I am putting a 2004 Yamaha RX1 engine in a mini buggy and am using the primary, secondary and chain case out of the sled. I am about ready to start test driving and was wondering about clutching. I talked to a guy that ran that engine years ago he remembered that he put lighter weights in the primary but could not remember which weights. Do you have any suggestions?

It depends on your gearing, traction and horsepower. I would leave the clutches stock and test your setup. I assume traction is going to be fairly limited so over shifting is a possibility, test and watch your rpm, report back and we can try to help with your setup.

Awsome buggy build BTW!

 

[givemeaboost]

That's going to be out of balance like that.


Ken............

 

[ClutchMaster]

That's going to be out of balance like that.


Ken............

the first post is from 2014, the second post is from yesterday.

View attachment 154067
Rat4020 I have a question for you. I am putting a 2004 Yamaha RX1 engine in a mini buggy and am using the primary, secondary and chain case out of the sled. I am about ready to start test driving and was wondering about clutching. I talked to a guy that ran that engine years ago he remembered that he put lighter weights in the primary but could not remember which weights. Do you have any suggestions?

Why did you post your question in a thread with only one post from 2014? Is your clutch damaged like the one in the first post?

 

[Turbotom22]

the first post is from 2014, the second post is from yesterday.



Why did you post your question in a thread with only one post from 2014? Is your clutch damaged like the one in the first post?

He was the only one I have found with the RX1/Apex engine in a buggy so thought if I put it here he might see it. I will do some testing and report back in a new thread. Thanks

 

[ClutchMaster]

How much gear reduction do you have from the jackshaft to the axles?

 

[Turbotom22]

The stock RX1 chaincase has 24 38 gears which gives a 1.58 reduction the sprockets are 10 and 46 teeth for a combined jackshaft to buggy axle of 7.3

I also calculated how this compared to the snowmobile and determined that using the stock 24 38 gearing, the track moves the sled 22.2 inches per revolution of the track drive shaft.

With the 24 38 and 46 10 sprockets with a 30 inch tire each revolution of the track drive shaft will move the buggy 20.5 inches, which would mean the buggy is geared about 10% lower than the sled.

That still seemed too high of gearing to me so I ordered an 18T top gear for the chaincase which will give me 38 18 or 2.11 reduction with 46 10 gives a combined 9.7 or if I go up to 46 12 combined would be 8.1 . I am worried that the 10 tooth chain sprocket is too small and the chain may slip so that's why I thought of going up to the 12.

I plan to weigh the buggy later this week too, I suspect its a couple hundred pound heavier than the sled.

 

[rat4020]

View attachment 154067
Rat4020 I have a question for you. I am putting a 2004 Yamaha RX1 engine in a mini buggy and am using the primary, secondary and chain case out of the sled. I am about ready to start test driving and was wondering about clutching. I talked to a guy that ran that engine years ago he remembered that he put lighter weights in the primary but could not remember which weights. Do you have any suggestions?

I started out with stock Yamaha primary clutch weights and a Arctic Cat roller secondary with a yellow spring and that worked ok with dirt tires but not paddle tires so I got a set of Heavy Hitters from Von at Thunder Products HHY48 they worked great and where easy to tune . Then I built a turbo setup for it 10lbs of boost and had to go with the HH58 weights and didnt change the washer configuration much at all and stitched to a green spring in the secondary. I also have a RPM gearbox with 10 to 1 reduction
sorry for not seeing replys to this tread notifications got turned off . But we decided that as members said, something had hit the primary