Jim's 1937 Columbia replica, with 66cc Flying Horse engine

Today, I returned home and for the first time, mounted my Flying Horse 66cc engine and I am very disappointed with how un-level the carb. is. The rear mount is solidly mounted and the engine is as low in the rear as possible (very near the chain guard) so, I'm not sure how to correct the tilting problem??

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Add to that, the carb. is too close, and even under the horizontal tube, a full 1/2".. making the high performance air filter impossible to use.


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I'm happy with everything else. I'm just not sure how to correct the tilted carb?

I wonder if I'm just overlooking something?

Any solutions would be greatly appreciated... :cry:

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Way nice build. I'm digging the tool bag under your seat.

Funny..... I think the leather tool container is everyone's favorite part of the bike. People point to it and say, "I like that." (not even knowing what it is) I had to seriously weigh the steep price-tag of the seat/tool bag.... against my love of history....... History won! (Even though they are replicas, they cost as much as the bike itself) As seen in earlier photos, they were originally brown but they looked like a brown pair of shoes with a black tuxedo to me. So, I rubbed off the dye with Acetone and re dyed them black. Now, they go with the bike.

Thank you,

Jim
 
This is a tensioner design I was looking at briefly last winter. I have since been working on a system that eliminates the tensioner.

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If the hillbilly appearance is faithfully maintained; it may also keep away pesky women and their expensive alimony.

It won't keep away Hillbilly women.... looking for alimony! :devilish:

I never responded to your design, and I really wanted to.... (Looks like a NASA wooden prototype)

Taking the tension out of the 415 chain is anything but "rocket science." I mean, there must be dozens of ways to do it. I once designed and built my airplane and I acquired a saying, "If it isn't simple, it isn't right." There's a lot to be said for "simple." I'm always looking for the straight forward way.

I've seen designs where the chain is lifted very close to the gear sprocket end and others lift near the sprocket on the axle end. Now, what I notice about your photo is that your method seems to lift the chain more in the middle. {I've had that nagging question in the back of my mind; which method would tend to eliminate a "frequency" in the chain? And, which position of the tensioner would put more of a load on the engine?} That would be a fascinating test. I'm thinking a tensioner wheel in the middle would be "less stressful" and (just for a test) building a wooden frame like the one you built might allow you to slide a spring loaded wheel fore and aft, to find that "sweet spot." I'm guessing most tensioner designs are near the sprockets because it is just a more convenient place to mount it.

Because I only have about 3/16" of clearance between my chain and balloon tire, the chain is making a mess of the white wall! The stationary tensioner might be fine, if there is enough room, but it doesn't seem to keep the tension tight enough to keep the top of the chain from moving side to side within that narrow 3/16" space. I can think of two options..... put on a narrower (even black) tire (when this one is worn out) and/or going with the style of tensioner, very similar to the photo I just posted trying to put on a constant tension.... If the tension is "jerky" I'll still have grease on my tire so it will mean putting a nice firm tension on that arm.

The first thing to do would be to build that spring tensioner...... wash the grease off the white wall and see if the problem is fixed.

Jim
 
Finished my bike Sunday at the stroke of midnight. The list of things to finish included a registration, re-dyed the brown leather seat and tool container BLACK, installed head and tail lights, a twelve volt 1.5 amp. car horn with a custom built 8-AA rechargeable battery holder (giving me the needed 12 V), analog old school speedometer (then removed), lengthened stock chain guard, ran and secured all brake and fuel lines,

Yesterday, was "bittersweet" as I was mixing the 20:1 fuel, my inspiration for building the bike, drove his car into my driveway to tell me, someone stole his chained-up motorbike. (Reinforces my support for the death penalty!) That was a huge heads-up for me! Well, I poured in only 16 oz. of the fuel. I could mark the low level next to my fuel-tube-sight-gauge. If there was going to be an engine problem, I would only have to drain one pint of fuel. So, I opened the valve and saw the fuel progress through the line; blue in the vitta fuel line, green in the filter.... and blue again. Hopped on the bike and started pedaling. It took about 4 tries with the clutch and China Girl fired up and I have to say, after reading about the roughness of the new engine, I was actually surprised how smoothly and quietly she ran. I was also a little surprised that there was little noticeable smoke.... (which I also expected from the rich mixture)

After the test ride

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My fuel gauge. Shows 1 pint of fuel (in an 18 pint fuel tank) Time to head for a station (within 6 miles) BTW, the bike is on the center duel-stand and tilted onto the front wheel in this photo. There are actually three indicated fuel levels; When leaning backward, forward, and when both wheels are on the ground. As you see here, when the bike is tilted onto the front wheel, the fuel level is very deceptive.

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The 12V car horn a la Roadrunner "Beep Beep" (It's as loud as any car horn with the small rechargeable 8-AA batteries seen mounted below.

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I found out immediately, how important the tension is, as I had to scrub grease off of the white wall. With only 1/4" of space on both sides of the chain, tension is critical. I'm interested in changing the tensioner to a spring loaded version possibly mounted to two frame supports. Any advice for a good system would be greatly appreciated.

Well, I hope some of you have enjoyed my build.

Jim

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wow jim,

that looks totally awesome, ill post some pics of a new build im doing soon, i loved putting my first one together so much i had to buy another kit (against my parents will haha)
 
My DIY Tensioners

I've been playing around with DIY tensioner ideas.... I actually was more interested in putting tension on the 410 chain and then got inspired with an idea of putting tension on the 415 chain (much like the builder used in my last post) as well. I modified my rear axle to be "fixed." That is to say, I traded a very straight and solid wheel for the ability to pull the axle back in the slots. It's nonadjustable so I like the idea of both chains being self-adjusting.

This shows the metal fittings I made for the 410 chain. I'm sure there are better ways to do it, but without a "hanger", I had to get creative. It feels very good, now that the chain isn't bouncing around.

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When the chain guard is back on, it covers the spring.

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As far as the 415 chain tensioner; I realized that I could use a spring with the tensioner that came with my kit seen below. The spring pulls up on the bolt in the diagonal slot, keeping tension.

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Instead of there being a spring pulling up on a pivoted arm, I just made a metal piece where the spring keeps tension on the bolt, pulling it up in the slot. (I had to round off the upper right hand corner)

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Again, with the chain guard, the spring is again hidden. Now, both chains have tensioners. What do you think, Wolfshoes?

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I should add..... I was having trouble with grease on my white wall. This last photo, was taken after my test ride. This spring fixed the problem of the chain wobbling into the tire! No Grease!
 
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My Columbia is still here doing parts run and loaner duty.
I just snapped this pic.

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We have ~300 miles on it now and we can't even remember the last time we had to put fuel in that 1.6 gallon tank ;-}

For me the stock tensioner right where the tire is was perfect.
How often do you see 2+" wide white walls without any oil marks?

No springs, wood, or anything else, and it can't go into the spokes.
Just a bearing riding pulley right in the perfect place to forget it once the chains and sprockets break in, and keep the chain from slapping the white wall tires.
 
Well, I guess part of the "art of MB building" is the opportunity for the builder to make their own innovations. Sometimes, we really do, just have to please ourselves.
 
I'm actually having a tank built by a welder that priced it too me for 50$..... Not including a 30$ Weld-in bung (vented).... And a 5$ fuel shutoff.... And I thought that the 50$ was cheap for a gas tank ;)

The tank should be right at .5 gallon
Plenty enough for small rides
 

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