In Loving Memory of Simone Gauthier,
August 26th, 1915 - February 18th, 2008

Tuesday, August 7, 2007

Yeah yeah yeah, WAY too long, AGAIN.... HUSH!

I've recently gotten married, and took a trip to Connecticut, where I was born to see my mom and Dad and most of my "best friends". Laura, John, Meia and Nick, love you all
!

Anyway, my dad gave me a "Pocket Bike" that he got for scrap. The bike was beat up a bit but otherwise complete. I stripped out the engine and all of the wiring. The engine is 49cc with electric start, and an 8:1 CVT. A CVT is a Constant Velocity Transmission. It shifts itself automatically based on the power that is being consumed from the engine. If you are going up a hill, it obviously takes more power and 'downshifts' but if you are on a nice flat stretch it will shift to give you more speed. The interesting thing is, you do not feel the shifting since it is done with a "v-belt" and two pulleys that are able to change their diameters.

On testing the engine I found that it would run happily on a spray of starter fluid into the carburetor but would not run at all from the fuel in it's own gas tank. This confused the hell out of my father and I. For those of you who know engines, there is no float bowl on this carb, just a primer bulb. It is a Diaphragm carb. For those of you who DON'T know what that means it's ok, because I just learned myself. There is a TINY port (the shaft of a Q-Tip just barely fits) out of the engine and into the carburetor. This port lets a small amount of the hot engine gasses from the combustion to feed back into the carburetor, where it hits a small rubber diaphragm. The pressure from the hot gasses moves the diaphragm towards a small supply of gasoline that has flowed into the carburetor from the fuel tank. The Diaphragm also serves to keep those hot gasses separated from the fuel supply and the rest of the carburetor. The pressure from the diaphragm forces that small supply of gasoline further into the carburetor for it to be mixed with air and delivered to the combustion chamber. At some point in time, the previous owner(s) removed the carburetor from the engine, and when they replaced it, they put a gasket on upside down and backwards which covered that port from the engine, so the diaphragm never moved, hence there was no fuel being pumped into the engine....

While I had the carb off, as I usually do, I decided to take stuff apart, just to see what was what. I found that the automatic centrifugal clutch assembly was damaged. These clutches work in much the same way as the drum brakes in a car, except for instead of STOPPING rotation, the whole thing rotates. As you know, brake pads and 'shoes' need to be changed occasionally. So do clutch shoes. The shoes were GONE from this clutch. $26 to replace them online from SDScooters.com.

So I called SDScooters to ask a few questions like "How can I charge the battery without the OEM battery charger?" and "Is there a cheaper way to replace the clutch parts?" and "Can I buy new gaskets for this carburetor?". During the course of the conversation, I also asked if they had any access to the wire diagram or schematic for my particular bike. They do not HAVE wire diagrams because no one MAKES diagrams... for ANY of the bikes. . . So I told him, "I have done my own diagram, and wanted a professional one to compare it to." I offered to show him the diagram I had done, and after emailing it, suggested that if they were to send me some harnesses, I would draw diagrams of the harnesses, and email the files back, in exchange for parts for my engine. The guy on the phone says "Tell ya what, send me your mailing address, I will send you the clutch parts, the charger, and another harness. Email me the diagram for the second harness and we'll call it a deal!"

So I now have, a running (as of yet untested but assumed to run) 49cc engine with a replacement clutch and all of the wiring for the electrical system (not the electronics such as the radio control system, just the electrical such as headlights and tail lights etc.) with a brand new clutch assembly and the original charger for the bike, at this point, all free! Now I am in need of the following:

* Gas tank, can be made out of anything that will hold gas, more than likely will be stolen from an old weed whacker
* Radio System, the 'big ticket' portion of this build, somewhere around $300, 2.4 Ghz system with more than 3 channels required...
* Chassis, to be custom fabricated, first from wood, then from steel.
* rear axle, this is not the most expensive part of the build but is turning out to be the hardest to find. I am looking for the rear axle from a "mobility scooter" because it will be chain drive and also contain a differential which will allow the wheels to turn at different rates when the truck is steering right or left.
* Body/Cab, to be custom made AFTER the final chassis is built.
* real axle. This is not the most expensive part of the built but is turning out to be one of the most difficult to locate. I am looking for the axle out of a "mobility scooter" like Grandma gets around the house in or handicapped folk get around Walmart in... When I find the right one it will have a chain drive and a differential all in one unit and will most likely determine the overall width of the truck since it will not be easy to change the length of the axles. . .


[Edit] 08/07/07 corrected typos/spelling mistakes.

2 comments:

Unknown said...

Sounds fun. :P I want photos of construction. And I thought you needed a comment on the page just because I felt like making one. Kay?

Blaise.B said...

Kay.