55 MPH Kart mod..

[Rail rider]

Who is going to try this ?

 

[Bbqjoe]

What happens when your dragging along an engine that doesn't want to go that fast?

 

[Hellion]

What happens when your dragging along an engine that doesn't want to go that fast?

I suppose the 0-25 MPH engine will be allowed to idle once the other one is spooled up to take over?
Its clutch and axle will then "freewheel"....

 

[chancer]

I do not see that as being necesary.

60/14 with 13" tires at 5500 Rpm is already 50 MPH.

So the money Spent on the second engine set up could be better spent making the Above Possible.
Or build a 6500RPM motor with 64/14 on 13" tires and ....bam 55MPH

 

[Bbqjoe]

I suppose the 0-25 MPH engine will be allowed to idle once the other one is spooled up to take over?
Its clutch and axle will then "freewheel"....

*Ahem* Who asked you????

 

[Whitetrashrocker]

Been done before to some extent.
Dad told me stories of his go karts. Ya know back in the 60s. He made one with 2 engines. One driving each rear wheel. He said it haulled mule.
Don't ask for blueprints though....

 

[chancer]

I guess that is in fact another way to hit 55+++
Just gear it right and Double the HPs.

Point is no need for two engines and gear set ups.

 

[OzFab]

I do not see that as being necesary.

60/14 with 13" tires at 5500 Rpm is already 50 MPH.

4.2:1 gearing sounds a little steep to me; It may be ok with a TC but, I can see a cent clutch being destroyed...

 

[Rail rider]

I'm not wasting good money on this... But here's the idea if someone else wants to.. PS both engines would run. And the one not powered up would free wheel

 

[Flyinhillbilly]

I have a hard time believing that the "take off" motor would freewheel without a manual clutch to disengage. My centrifugal clutch don't just release when I let off the gas, I had engine braking until the rpm drops low enough to disengage.

 

[Randy H]

You could add a one way bearing to the setup. Or.

http://www.diygokarts.com/vb/showthread.php?t=8281

 

[Jfive]

They don't make them anymore and it would cost a lot to try and replicate that one Randy. It's been brought up a lot and after hours and hours of research I gave up on that one. A cvt tav30 was a better option imo. This thing did have me wondering.

 

[Randy H]

That's interesting. I'd be a hog headed liar if I said I knew exactly what was going on there. Any more info? Linkage?

I've been studying up on the two speed clutch too. I'll see if I can't destroy some chinese bearings (one way). I think they are the weakest link. If I can't break it, I'll send it to FHB

 

[Jfive]

Look up two speed scooter and you can find some info. It's a Asian scooter design. In production at least. You should watch the YouTube video on Chinese vs German bearings. I found it very interesting.

 

[chucKart]

I have been wanting to do the same exact thing as I have a couple briggs fun power 5s laying around. I would however mash both pedals to accelerate and then slide my foot off the low speed pedal to the high speed pedal.

And to address the clutch disengagement "issue", both of my yard kart clutches disengage the moment I let off the accelerator, the engine speed drops to a hair above idle and I keep coasting near top speed. Especially when going down hill. If the engine isn't spinning to sling the inner clutch out to grab it isn't going to grab.

 

[Jfive]

http://scooter.wikia.com/wiki/Evo_two_speed_transmission

Link on two speed scooter transmission

 

[Kartorbust]

Can't you just use two centrifugal clutches and adjust one to take off sooner than the other? I mean they use to sell two speed setups a few years ago, not so much now, just the dual sprocket clutch needed. Why not just get a dirt bike engine and build a shifter kart that way? Not as much fabrication needed and the transmission is already there. Something like a Honda CRF125 will do the trick I bet. They use to use 2 stroke CR125 in shifter karts, but switched to 4 strokes later on.

 

[Flyinhillbilly]

If you have enough power, one gear is enough.

 

[chancer]

If you have enough power, one gear is enough.

Thanks You!
That was my Point earlier. I mean if you build a powerful enough engine to handle 7000RPMs, You are GONNA Have the HP to overcome and a 4:1 Ratio Become possible. Easily Achieving 55 to 65 MPH.

 

[Functional Artist]

If you have enough power, one gear is enough.

Go Electric!

You don't need no stinkin' gears or clutch.

Just gooooooooooooooooooooooo