Manual transmission with predator 212

arcticblobfish

New member
Messages
7
Reaction score
0
So I'm thinking of making a go kart using a Predator 212 6.5hp that has a 2 or 3 speed 1 reverse (at least one gear high torque and another high speed). What sort of clutch should I use and how would I figure out the gear ratios for the transmission? Aiming for 45 mph top speed. Thanks for the help.
 
Last edited:

RLS_Underground

Active member
Messages
273
Reaction score
89
If you do the engine right, use a CVT, and get the gear ratio right for the curb weight and tire size it should be very capable of well over 45.

The Husqvarna 208 I run on a bike will do well over 65 with 26" biycle wheels, and 3.6:1 gearing... I only needed to do it once to know it wasn't safe over 45, and by 75 I was ready for fresh undies.
 

arcticblobfish

New member
Messages
7
Reaction score
0
If you do the engine right, use a CVT, and get the gear ratio right for the curb weight and tire size it should be very capable of well over 45.

The Husqvarna 208 I run on a bike will do well over 65 with 26" biycle wheels, and 3.6:1 gearing... I only needed to do it once to know it wasn't safe over 45, and by 75 I was ready for fresh undies.
Are you saying to use a cvt along with a manual transmission?
 

RLS_Underground

Active member
Messages
273
Reaction score
89
No I'm saying that with a CVT you don't NEED a transmission because it is one, although its fully automatic with no reverse.

With a CVT, the right final drive ratio gear ratio for your tire size, engine output, and cart weight, your kart could easily be set up to do well over 45mph with a a 0-30 in 250ft or less.

If you want a reverse gear you're probably not going to be able to use a CVT.

The issue with all the manual gearbox transmissions I've seen (3s,4s, and 5s) and even just the reverse boxes is that there is 90° rotation between the input and output shafts. You're going to require either 0° (same side) or 180° (exact opposite) for it to work properly
 

arcticblobfish

New member
Messages
7
Reaction score
0
No I'm saying that with a CVT you don't NEED a transmission because it is one, although its fully automatic with no reverse.

With a CVT, the right final drive ratio gear ratio for your tire size, engine output, and cart weight, your kart could easily be set up to do well over 45mph with a a 0-30 in 250ft or less.

If you want a reverse gear you're probably not going to be able to use a CVT.

The issue with all the manual gearbox transmissions I've seen (3s,4s, and 5s) and even just the reverse boxes is that there is 90° rotation between the input and output shafts. You're going to require either 0° (same side) or 180° (exact opposite) for it to work properly
Ok thanks for the info on the CVT. I'll look into using one. About the manual transmission, I don't completely understand what you mean by the 90 degree rotation between the input and output shafts. Could you explain it again? Sorry.
 

RLS_Underground

Active member
Messages
273
Reaction score
89
Ok thanks for the info on the CVT. I'll look into using one. About the manual transmission, I don't completely understand what you mean by the 90 degree rotation between the input and output shafts. Could you explain it again? Sorry.
The shift linkage is always on the top, the input is always on the Left end... if the output is on the bottom... it's 90° from the input. There's a reason we don't use vertical shaft engines and basically all the transmissions convert the horizontal input into a vertical output.

Even if you were to turn it on its side so the shift linkage wasn't on top, the only way I could see one making it work would be to actually rotate the engine 90° (output shaft facing rear not side) and then also rotate the gearbox 90° (output to the side, input forward.

The easiest way to connect the 3/4" engine output to the 5/8" 9 tooth splined gearbox input that comes to mind would be either a very expensive hard to find manual kart clutch, stick a gear on the splined shaft and connect the two together with a length of chain.

That still doesn't solve the issue if hooking up a shift linkage that definitely needs to be a push/pull rod type of an unknown length, bent to multiple angles for clearance without compromising linear strength and rigidity.

As I'm explaining it, I can tell you as much as that It would look simple drawn up in a schematic, but the actual fabrication and mounting of the actual parts... would be a total nightmare for anyoneone with bare basic mechanical understandings.

EDITED: Missing/incorrect information
 
Last edited:

arcticblobfish

New member
Messages
7
Reaction score
0
That clears it up, thank you. Last question, would you say that using a manual transmission is too much of a hassle to be worth it?
 

RLS_Underground

Active member
Messages
273
Reaction score
89
That clears it up, thank you. Last question, would you say that using a manual transmission is too much of a hassle to be worth it?
Most definitely.
No offense intended, but I get the read that you are not particularly the most mechanically advanced, or accustomed to inventing oddball one off bits and pieces for necessity that otherwise just don't exsist
 

arcticblobfish

New member
Messages
7
Reaction score
0
Most definitely.
No offense intended, but I get the read that you are not particularly the most mechanically advanced, or accustomed to inventing oddball one off bits and pieces for necessity that otherwise just don't exsist
Only in high school, so still learning. Thanks for all the help!
 

Willie1

Active member
Messages
132
Reaction score
68
Location
Newport, Mi
The Peerless 700 series is the trans most people run in the racing mowers and such and have been fitted into lawn karts by people wanting speed selection, reverse, and mostly - to develop their fabrication skills. They have been used widely in small rear engine and stand behind mowers and have many variations and gear ratio selections. Properly built, they can be reasonably sturdy, but they do not like being shifted while moving. Also, racing karts remove the (internal) chain and disable reverse, as when the chain fails, it destroys the case. The only way to use one in a kart and use a horizontal shaft engine is to also run a 90* gearbox, which adds expense and fabrication - as has been said - they are designed to be used with a vertical shaft engine.

As they are typically mounted - the shift shaft is on top. Power goes into the bottom of the unit, usually through a v-belt pulley, and the belt is also the clutch through a pedal/idler setup. Not all models have outputs on both sides. On the one shown, either side can be fitted with a chain drive output sprocket, and many times there is a small brake on the other end. Rotate mounting it 180* and the output shaft changes direction.

They do not like shock loads, as in clutch dumps. They do not like being shifted while moving - you can, but shouldn't; it damages the drive keys. They tolerate torque better than RPM, so it is better to add speed with your final drive sprocket ratio than by spinning the input faster. And you still have to use a 90* adapter to run one with a Clone motor, which, might be $150-200 new or a $20 garage sale steal.

So the point is - can it be done? Yup. Easy? Nope? Cost effective? Not even close. LOL
With the proper teacher it would be a great learning experience, because it would challenge
and develop your fab skills. More of a project to use up a bunch of parts laying around,
than one where you have to source them and probably pay retail.

I hope you enjoy whatever project you end up building. Willie
 

Attachments

  • transmission-peerless-700-070a-bobcat-ramsom-4127203.jpg
    transmission-peerless-700-070a-bobcat-ramsom-4127203.jpg
    72.7 KB · Views: 3

arcticblobfish

New member
Messages
7
Reaction score
0
Why is the 90* gearbox needed with a horizontal shaft? Also, thanks for the info on the transmission. I didn't know about it and it'll be great for my project.
 
Top