TOM THUMB by MANCHESTER

boatguy

boatguy

#61
#61
Karen when I first started on my Tom Thumb I was going to use a 49cc engine.I found a complete pocket bike for $50 and took it apart including the motor mount plate and it fit in perfectly.I would have to customize the exhaust but it could be made to fit. My only problem was in figuring out the gearing using a jackshaft. In the end I chose the West Bend 820 which I already had and I could get it to fit. I agree the O&R won't give you enough power. The other option is a 2 stroke Tecumseh motor. These engines as with all 2 strokes they can be run on their side which with only 8 in clearance this certainly helps.There is a pic of this set up under the OldMiniBikes past articles when you type in Tom Thumb. Also the 49cc motors run small chain so you will need there sprocket as well. If I can help further--be happy to and your bike looks great--Bill.:thumbsup:
 
manchester1

manchester1

#62
#62
x-90 rider said:
I hate to say it but just Google "pocket bike engines". Start asking sellers questions about dimensions, carbs, pipes, and parts availability. I looked a long time for something that was short enough to fit in my frame. A new high quality european engine with carb and pipe is probably going to be over $800 and a Chinese clone with carb and pipe should be under $200. But, there are plenty of good european engines on ebay for decent prices. Keep in mind that a decent 49cc engine will easily put out 3+HP. :scooter:
Click to expand...
Thanks Jim. I'm in no great hurry but I have been surfing the web:laugh: I saw those chineese engines, they are pretty cheap. I would probably have to do alot of mods to get it to work. I'm still surfing:laugh::laugh:
 
manchester1

manchester1

#63
#63
boatguy said:
Karen when I first started on my Tom Thumb I was going to use a 49cc engine.I found a complete pocket bike for $50 and took it apart including the motor mount plate and it fit in perfectly.I would have to customize the exhaust but it could be made to fit. My only problem was in figuring out the gearing using a jackshaft. In the end I chose the West Bend 820 which I already had and I could get it to fit. I agree the O&R won't give you enough power. The other option is a 2 stroke Tecumseh motor. These engines as with all 2 strokes they can be run on their side which with only 8 in clearance this certainly helps.There is a pic of this set up under the OldMiniBikes past articles when you type in Tom Thumb. Also the 49cc motors run small chain so you will need there sprocket as well. If I can help further--be happy to and your bike looks great--Bill.:thumbsup:
Click to expand...
Thanks Bill, I'm in no great hurry but I am always looking. I do have this old 2 stroke enginge in the garage. I think its a tech. I'm going to dig it out on sunday and take a peak. :thumbsup:
 
old-timer

old-timer

Scamming Member
#64
#64
Karen that bike is coming out fantastic :thumbsup:

I take my hat off to you my friend :wink: I always thought the TTs were such a cool little bike. I feel so rookie right now :doah::laugh:

Vic
 
buckeye

buckeye

Well-Known Member
#65
#65
I am with ya Vic. I am questioning why did I bother entering.
I could have made a fool of myself in a regular project log not against this kind of a quality build.
Great job K!!
 
manchester1

manchester1

#66
#66
Thanks Buck and Vic. This bike is not in the build off because it will probably take me 2 years :laugh::laugh: Right now I am trying to make a "form" so I can pinch the tubes:doah:
 
manchester1

manchester1

#67
#67
Well I had my tom thumb all set up and took it to my professional welder. I had the welds so sloppy he made me start over:laugh::laugh: Anyway, I picked it up today and its all welded up :thumbsup::thumbsup: I just need to clean the welds up a bit. I'm hoping tomorrow I can get the front tubes pinched some place around town:laugh: I also picked up these great wheels on e-bay:thumbsup::thumbsup:


 
jeep2003

jeep2003

#70
#70
gotta love it :thumbsup: the 4" mancos are a nice fit on the little bikes. to make crush dies for the forks all you need to do is drill a hole in a 1/2" plate the size of your tubing. 5/8 or 7/8 whatever. then cut it in half through the hole so you have the half circles. then you can heat the tubing and crush it in the vice using those plates to form your ends
 
manchester1

manchester1

#71
#71
jeep2003 said:
gotta love it :thumbsup: the 4" mancos are a nice fit on the little bikes. to make crush dies for the forks all you need to do is drill a hole in a 1/2" plate the size of your tubing. 5/8 or 7/8 whatever. then cut it in half through the hole so you have the half circles. then you can heat the tubing and crush it in the vice using those plates to form your ends
Click to expand...
Thanks Jeep. So its ok to use some heat on the tubes :shrug: I tried to do it in a vise with a breaker bar and they didn't move a hair:laugh::laugh:
 
bigrob

bigrob

#73
#73
Looking good Karen , I quite often mix up some bondo and "caulk" my less than pretty welds its easier to sand it smooth than grind the welds you dont loose any strength
 
manchester1

manchester1

#76
#76
I found some steel plate in the garage, I didn't think I had any left. I'm going to try and pinch those tubes myself tomorrow. I'm scared :scared: because it always takes me 2times to get something right and I only get one chance. :doah: I'll practice on a piece of tubing first:thumbsup:
 
You must log in or register to reply here.
Top