Quote:
Originally Posted by metalstudman1
MB165 is a mini bike w/ a 165cc? Sorry this started out as a buggy thread! Something is wrong if you're cooking a belt like that. You have to be a member to view the link.
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Sorry about that I forgot.
Here's a walk around on Youtube.
http://www.youtube.com/watch?v=EkxXq...1&feature=plcp
Same drive components as the Yerf Dog 3203.
9 tooth primary drive to the same 54 ratio sprocket as the Kart.
Same primary and secondary clutch.
Engine is a clone however and not the Tech motor the dog uses.
Displacement is a little less at 196cc, but its been modified a little.
Something wrong about turning a belt to crumb rubber in under an hour lol?
Ya lol.
There is lol......
The 9 tooth primary drive though is a great thing to do for added low end torque.
There is still a problem it was factory tuned for an engine making 9 pounds of torque at 3600 rpm.
And I think everyone with a kart or bike using these things is exceeding the torque or speed ( and usualy both ).
Net result is the clutch transitions too soon and does not have the amount of clamping force on the belt handle the extra power.
The belt slips once its fully transitioned and its actualy riding high ont he primary further limiting the contact between the primary sheaves and the belt as well as making slip worse ( and rapind belt wear ).
Solutions:
Still working on that.
softer primary springs may help with the early transition as well as cranking up the secodanry tension.
But ultimately I think the second mystery gold spring Comet made was deisgned to increase the clamping force and retard the trasnsition from high to low ration and increase the clamping force on the belt.
Hard to say though not a lot of discussion and information on how to tune these and there is a very limited stock of parts to work from.
See here on this ebay auction.
http://www.ebay.ca/itm/Comet-20-30-S...item519fba1407
This fellow has posted a chart indicating what springs and weights were avaiable at one time.
Some of these obviously were for a 2 cycle aplication, maybe the Chrysler westbend engine used in the Rokon back inthe 60s and 70s...
In nay event having access to these parts might make getting the clutch to run more in that intermdiate possition of not fully open or closed for most of the time easier to achieve.
MIght try and put some rosin on the belt too to see if it will bite a little harder and reduce the slip.
Next stop.
A salasbury 340 if I can find such a beast because the 40 series will not bolt to the engine ( unless there was a 3/4 inch version driver I am not aware of ) or a far more expensive clutch deisgned for Jr drag racing.