Micargi Puma with twin 97cc flat top lifan's

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LabRat

New Member
Dec 24, 2011
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Ruston, Washington
AWESOME!
Comeing along looking realy good. Glad to see you are back at it, been a wondering how you were doing................Curt
Yes as with most I have been having a wonderful summer. Not much has been happening in the laboratory if not because of the summer activities but because summer ended and now I am back to work at work and I work a lot.

This does however supply the funds to continue this project and begin some anew.

Missed ever deadline I set for myself with this build.

Major hurdles remaining to finish this build are: a) sorting out a gas tank. b) designing the seat pan. c) design and build of roller bearing jackshaft.

Pretty much have remaining parts on order and awaiting shipment. Parts remaining to be purchased are roller chain for secondary and a clutch.
 

Crazy Horse

Dealer
Feb 20, 2009
1,153
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LabRat, following your build for quite some time. It's impressive to say the least.

Thought you'd enjoy seeing this build by a friend!

Information about this Twin Engine Schwinn Stretched Chopper Bicycle Build, pedals removed:

That blue bar is temporary since the engine mounts are not completed in this picture. When the bottom mounts are complete, then a top mount between the two heads and the backbone pipe will be fabricated. A chain guard will fasten into that blue bar area, and that aluminum sounds like a good idea. The bases of the engines are as close as they can get mounted in the V shape, I even changed the oil drain plugs to short allen wrench types to get them as close as possible

LabRat:
The engines are locked together and timed so the second engine fires 315 degrees after the first engine fires. The second engine has a cent. clutch that drives a jack shaft in the opposite direction of the engines and then goes to the back tire. That's right, the engines as you look at the picture rotate counter clockwise and the back tire has to rotate clockwise. That was a surprise I had to deal with, never thought about the engines running backwards with the way I wanted to mount them. As for the pipes, I like them the way they are. Actually I built the front pipe first around the front crank shaft and then the back one that had to clear the clutch. Their shape has more to do with where there was room to put them than what I would like them to look like. Would have been nice to have the identical. The front one could be reshaped a little bit, but not much.

The seat pan is cut out but not shaped, the original rear fender will get all the holes filled and be remounted. Two ideas for a tank, one is to cut the backbone out and replace it with a 3" or 3 1/2 " tube and use that for the tank. That would retain the original bicycle look and hold about a gallon, the other is about an 18" long slender "coffin" shape tank that will hold about a gallon and go on the frame as it is now. As for controls, I have a throttle twist grip to make it go and a new pair of boots I can drag to get it stopped, what else do you need? Actually I'm researching a disc brake that I'll need to turn a hub for to attach to the back wheel, or possibly just the original caliper brake. Sorry, but I don't make sketches on paper very often, mostly ideas that just develop as I go.

The motors are 3 hp Tecumesh. They have plenty of power if necessary can a smaller sprocket on the rear wheel to increase the ratio. Top Speed about 30 pmh in the current configuration and 45 mph if using the smaller sprocket.

The engines are pull start. The engine mounts finished now (made a change in that plan) and seem to be sturdy enough that the top mount off the heads to the backbone is no longer in the plan. The 315 degree is for sound, Harley type. Harley cylinders are 45 degrees apart, the front cylinder fires at 0 degrees, rotates 315 degrees, then the back cylinder fires, then rotates 45 degrees to complete the 360 degree circle.

Crazy Horse.
 

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LabRat

New Member
Dec 24, 2011
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Ruston, Washington
Crazy Horse this build you posted; I had seen the finished bike posted someplace. But I had no back story on the build.

Should I repeat this type build, think I will opt for 5hp flat to brigs or something of the sort. Puma twins are 2.5hp each. The 97cc doodle bug aka lifan engine's have tiny intake and exhaust ports.
 
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buba

Member
Jul 2, 2010
914
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los angeles
crazy

thanks for posting your friends build
I have been chopping a few oc cruisers and putting drop loops in them
the straight splice stretch looks great especially with paint
 

LabRat

New Member
Dec 24, 2011
596
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Ruston, Washington
Sorting out the jackshaft and clutch placement. The Brackets for the plate were sourced on eBay they are used to hold antennas to post were purchased for a 1.25" post. The center pipe in play is 1" so spacers had to be made by bending a piece of aluminum plate. Photo shoes the process. Then roughing in the plate to hold the brackets. This is just a mock up with the incorrect sized shaft (5/8") the shaft being used is actually 3/4" and shown here with a dead and used clutch. End is a slice away view of the bracket that holds the JS plate to the frame.
 

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curtisfox

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Dec 29, 2008
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Sorting out the jackshaft and clutch placement. The Brackets for the plate were sourced on eBay they are used to hold antennas to post were purchased for a 1.25" post. The center pipe in play is 1" so spacers had to be made by bending a piece of aluminum plate. Photo shoes the process. Then roughing in the plate to hold the brackets. This is just a mock up with the incorrect sized shaft (5/8") the shaft being used is actually 3/4" and shown here with a dead and used clutch. End is a slice away view of the bracket that holds the JS plate to the frame.
This is realy KOOOOOL and liking it. I think though with the torq you will have just the clamp it might flex on the tube,so i would consider a rod or something for a stableizer to keep it form doing that............Curt
 

LabRat

New Member
Dec 24, 2011
596
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Ruston, Washington
Updates on the Jack Shaft construction. This is a mock up and subject to changes are some are noted already to be made. You may see the chain is on the frame this will be addressed. Also the plate at the top, had to remove to much material and the plate will need to be re cut for cross sectional strength. This is the first attempt at a drive system. Re do is to be expected.
 

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LabRat

New Member
Dec 24, 2011
596
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Ruston, Washington
Formed a solid pan to filling in the area between the frame over engine #2. This ties it all together aesthetically while adding cross sectional strength. The seat attached in the last picture came with the original bicycle.
 

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LabRat

New Member
Dec 24, 2011
596
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Ruston, Washington
Did not like the seat. Just looked at it and looked some more didn't like it. Sat real nice but the style was not there. So I reworked the seat three times with metal pan. Still did not like what I was seeing. Swear I have 10hrs invested in how to sit on the motor assisted bicycle. Here are some pix of where it is now. The nice base seat was taken from a OCC chopper. The extension was made from the arm rest of an Invacare wheel chair. Same wheel chair I used for DieselDave's twin exhaust pipes.

The hinge is made from a gate hinge. The hinge pins are the ends of the long gate pins that would screw into a post I cut the heads off. In one of the pix you can still see the treads hanging off as I am test fitting to understand what I am doing.

Note in pix #4 you can see the rear seat springs. I chopped up three old useless 70s era two spring seats before finding a pair of springs that would work with this design.
 

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