Centrifugal clutch question

[petite morty]

Success!

Well, having run out of any other options, I purchased a new centrifugal clutch...and it worked! The bike starts up and idles with no problem. And I was able to get a refund on the bad clutch as well. I put a more appropriately sized driven pulley on the jackshaft (thanks srdavo), so I now have a 3.2" clutch pulley to a 4.5" driven pulley on the jackshaft, and a 1.5" drive spindle. Top speed = about 15-18 mph, which is maddeningly slow on the street, but will be perfect for picking my way through crowds at Burningman. I still need to put a idler pulley where the v belt rubs where it crosses over itself, and build a cover over the clutch/belt/pulley, but basically it's together and working. I borrowed a camera, so here are a few pics.

 

[Large Filipino]

(ahh. It's welded.)
Dude. If you flip the friction drive to the right and turn your engine to the right,would that allieviate you having to twist that belt like that?

Wait. What teh...does that engine spin counter clockwise?

We need to look at your rope starter. I have a feeling that's on backwards or wound wrong so when you're pulling the rope the engine's actually running backwards...yes..this is possible.

 

[petite morty]

I really dont want to flip the engine the other way because I have a sidecar on the right, and don't want the engine exhausting in the sidecar riders face.

BUT...the engine does turn counter clockwise, looking at the end of the drive shaft. Thats the way it rotated when I pulled it off of the snowblower I scaveneged it from. I took a look at the pull starter case, and it does look like it could probably be rewound to turn in the other direction. Would the engine run in a different direction just by pull starting in a different direction?
I seem to remember some references here on the forum that you would have to change the orientation of the magneto to change the rotation of the engine.....

If I can get the engine to run "backwards" without major engine/magneto mods..that would be great for simplifying the design...

 

[petite morty]

Well, I guess I answered my own question. I pulled off the pull starter cover and just wrapped a pull cord around the flywheel pulley, and tried starting the engine in the other direction. It won't start.

Of course another course of action would have been to flip the engine and build an exhaust pipe and muffler so that the exhaust would not blow in the sidecar riders face, but..... I dont have any tubing bending equipment, blah blah blah, and it just seemed like a bigger job to do it that way. Besides, even though it seems kind of wierd, the infinity belt actually seems to work OK. Even without an idler pulley where the belt crosses over, the belt does not seem to rub much on itself. When the bikes moving, the belts flaps around. It's more like the belt is just slapping against itself, rather than continually rubbing....

But still, if I found a reletively easy way the reverse the engine rotation, I would go for that....any input out there about reversing engine rotation?

Oh yes, and one other thing I forgot. I will need to bend the crank to allow for the wide engine as well if I am going to peddle it much. Or I might just be lazy and use the pedals for footrests and never peddle it.

 

[kerf]

Could turn the seat around and run in reverse, steering outboard style. Keep plenty of bandages in the the ol tool bag, could be a rough ride.

Your best option is to turn the engine and handle the exhaust issue.

 

[Large Filipino]

Maybe you can snag up them wide cranks that come with those 4 stroke kits.

It's actually pretty cool seeing that belt like that. Heck,if it works,it works!

So what's this about a sidecar?

We need some pics!

 

[srdavo]

morty,
I like your design. specially the way your engine mounts to the frame.nice work!!
I wouldn't change a thing.
It should be easy (for you) to build a belt guide of some sort, for your infinity belt.

I agree with Large about the wider pedal cranks. they should be easy to find. do you have one piece cranks? I know of a vendor who used to carry wide one piece cranks.

you could squeeze out a few more MPH's If you went 1:1 on your pulleys....but as is, I'll bet you have great take off power. you'll need that hauling passengers.
once again....nice work!

 

[petite morty]

Thanks for the input...I will start learning to drive backwards...hehe.

It does have a LOT of torque for taking off, which really helps for carrying a 170 lb sidecar passanger on dirt. Which is one reason I may not worry about the crank, because its really hard to peddle a passanger under those conditions. Even using low gears. Still.....if you know where to find a wide one piece crank, Davo, please let me know.

I will take some pics of the sidecar when I get it out of storage soon, Large P.

 

[Large Filipino]

It's thirty bucks but here's what I found.

http://www.bicycle-engines.com/wide-crank-pedal-p-106.html