Torque convertor problems / wrong gear ratio

[shelby1]

Ok if any off you have fallowed what I have done with my grand sons Murray kart, well he has gone tru 3 drive belts with 2-3 hours run time , the first was because I did not line up the drive and driven pulleys, fixed that and two more belts ( at about 25 bucks a pop) burned and rolled on the flat side. Ok I have went back tru every thing on the kart and I have two questions, the large nut on the driven pulley , according to instruction sheet the tighter the nut is the higher the rpm that it will shift from 1:1 to .95:1...... I wondering that because the nut was not tight enough and it was shifting to higher ratio ( lower number ) and causing much harder drive pressure on the belt.

The second question is the gear ratio may be too tall ( lower number wize) as the primary sprocket is 10 teeth, driven sprocket 36 teeth which is 3.6 :1 with a 16 " wheel ...... to my way of thinking I,m thinking it should be around 5 to 6 to one.

Help me Guys!!!!!!


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[Randy H]

You'll be much happier at 6:1.

 

[bob58o]

Yep, assuming you have around 5-7HP engine, with 16" tires, Replace that 36T with a 60T.

How fast did your grandson go?
If it ever hooked up properly.... It was geared to do 52 mph at 3600 RPM.

 

[Bbqjoe]

Ok if any off you have fallowed what I have done with my grand sons Murray kart, well he has gone tru 3 drive belts with 2-3 hours run time , the first was because I did not line up the drive and driven pulleys, fixed that and two more belts ( at about 25 bucks a pop) burned and rolled on the flat side. Ok I have went back tru every thing on the kart and I have two questions, the large nut on the driven pulley , according to instruction sheet the tighter the nut is the higher the rpm that it will shift from 1:1 to .95:1...... I wondering that because the nut was not tight enough and it was shifting to higher ratio ( lower number ) and causing much harder drive pressure on the belt.

The second question is the gear ratio may be too tall ( lower number wize) as the primary sprocket is 10 teeth, driven sprocket 36 teeth which is 3.6 :1 with a 16 " wheel ...... to my way of thinking I,m thinking it should be around 5 to 6 to one.

Help me Guys!!!!!!


Sent from my iPhone using Tapatalk

Maybe I smoked too many marijuanas with my coffee this morning, and unless your driven is different than the three I own, I've never seen ANYTHING about tightening the nut to adjust anything about shifting.

 

[bob58o]

Maybe I smoked too many marijuanas with my coffee this morning, and unless your driven is different than the three I own, I've never seen ANYTHING about tightening the nut to adjust anything about shifting.

except I don't drink coffee.
From what I understand you have to swap the driven spring or change which preload hole that it is installed into.

 

[shelby1]

Maybe I smoked too many marijuanas with my coffee this morning, and unless your driven is different than the three I own, I've never seen ANYTHING about tightening the nut to adjust anything about shifting.

well I thought that it was a little strange for the instruction sheet to say that .....cause it did not really make sense to me but I am new to the torque belt set up so......did not know any thing about it. I will bring the instruction sheet home and copy and post it for all to see.My main concern was about the final ( chain drive ratio ) as how it compared with tire size. On the racing karts that I worked with years ago the final drive sprocket was not much smaller than the drive wheels .And when your butt is only a inch off the ground it was scary how fast those karts were.
Kenny

---------- Post added at 02:42 PM ---------- Previous post was at 02:37 PM ----------

How fast did your grandson go?
If it ever hooked up properly.... It was geared to do 52 mph at 3600 RPM.

Oh now that is just scary .......that boy only knows one speed ........and that is wide open, thank goodness there is no wide open spaces where he rides , only a acre that is on the rough side and no long runs.........
Kenny

 

[Mr. Spindle]

except I don't drink coffee.
From what I understand you have to swap the driven spring or change which preload hole that it is installed into.

What?!?! No coffee? I do.