Columbia 1937 board tracker real gas tank

I normally don't build on ~$150 wally world type bikes but this caught my eye.
http://www.walmart.com/ip/39801995?...7321352&wl4=&wl5=pla&wl6=105949407872&veh=sem

The 'tank' is two pieces of pressed formed sheet metal that butt together in the middle via 2 struts attached to the frame via cut outs, two screws on each side plate, and top mounting hole to strut between the split top bar.

I thought I'd see if I can make it wide enough to get a filler and petcock on it and seal it up like Sportsman does.

I made new inner struts to widen the front 7cm wider and the rear 3.5cm wider.
NOTE: flattening the front struts V mount out straight gives you the back strut.

That leaves me enough room for the petcock, and with the wider front enough room for the filler I hacked off an old kit tank.

I found a spiffy thinner steel filler and venting cap that that is pretty darn cool.
If the bike falls over all you get is a little drip from the tiny vent hole as the cap is threaded with an O ring seal.
http://www.ebay.com/itm/Custom-Fuel...h-weld-in-Bung-SMALL-CUSTOM-NEW-/191495380281


For the petcock I'm going with the new MB kit one with the threaded collar so you can orient the valve lever and it has a double long inner screen with a Normal and Reserve setting.
http://www.gasbike.net/gasoline-tank-switch-for-2.5-L-gas-tank.html

Reserve on this flat tank should be enough for 10 miles or more.

I got some poster board to cut out the templates for the sheet metal and thinking I'll just pop-rivet it on because I found this to seal up the tank.
http://www.caswellplating.com/restoration-aids/epoxy-gas-tank-sealer.html

A gas-proof liquid 2 part epoxy that creates a solid tank inside the shell.

Under $100 to NOT use a peanut tank is worth it, and the bike itself has potential for handlebars down board tracker feel or sit up nice beach cruiser.
Worth exploring for me ;-}

 

[KTOKTO]

This build...

Do you think a 49cc four stroke and jack shaft would fit on that frame? Just tossing around ideas.

 

[Frankenstein]

Do you think a 49cc four stroke and jack shaft would fit on that frame? Just tossing around ideas.

By eye it looks feasible. Actually looks big enough for a 79...

 

[butre]

it would definitely be enough for a 49 but it looks awfully cramped for a 79

 

[KCvale]

Do you think a 49cc four stroke and jack shaft would fit on that frame? Just tossing around ideas.

No.
I had to use an offset intake just to get a 2-stroke in it.

I only bought the bike because I thought I could use the 'gas tank' and ended up speeding over $300 to make it so.
In short, a poor choice for a motorized bike.

 

[Frankenstein]

it would definitely be enough for a 49 but it looks awfully cramped for a 79

Couldn't be any worse than the engine compartment in most vehicles, cramped is still fitting one way or another lol...

 

[KTOKTO]

No.
I had to use an offset intake just to get a 2-stroke in it.

I only bought the bike because I thought I could use the 'gas tank' and ended up speeding over $300 to make it so.
In short, a poor choice for a motorized bike.

You're talking just money-wise right? I can build the tank myself. Lke I stated earlier, I am basically interested because of the steel frame and I like how well the motor fits in the one you built.

 

[panmines]

Do you think a 49cc four stroke and jack shaft would fit on that frame? Just tossing around ideas.

I made a 68cc with a tall cylinder head and jack shaft work on another very similar Columbia frame. I had to tweak the jack shaft set up by moving the right sprocket and chain ring out away from the bike so the engine could sit further down in the frame. I also ditched the right hand chain tensioner assembly because it could not fit on the seat post beneath the engine and I can adjust the tension elsewhere by adding more spacers on the front mount. For the chainset to reach the offset jack shaft, I used the 206 mm bottom bracket cartridge Sick Bike Parts sells and 50mm M5 bolts for the chain set assembly. You can also see in the photos I used the stock 36t chainring in between the the two other chainrings to give the system more support. Thankfully the 44t and 36 have four larger holes drilled in to them and I could slip some thick 35mm bolts through them.

 

[Sanny M. Odulio]

nice build

 

[panmines]

nice build

This is what it looks like today:

Resized

• panmines
• Mar 12, 2018

 

[KCvale]

I had to tweak the jack shaft set up by moving the right sprocket and chain ring out away from the bike so the engine could sit further down in the frame.

Ohhh my.

It is generally good to mount your engine as low it can go, but not so low that it creates problems!!!