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

Discussion in 'Photos & Bicycle Builds' started by PocketBiker, Mar 9, 2015.

  1. PocketBiker

    PocketBiker Member

    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??


    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.


    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... :sweatdrop:


  2. dougsr.874

    dougsr.874 Active Member

    The one I built is the same way...but the engine seems to run fine like that so I'm leaving it alone even tho I don't like it.
  3. PocketBiker

    PocketBiker Member


    Well, my neighbor was over tonight, and he knows a good welder who can weld aluminum, so I think, we're going to modify two of the angles. After contemplating it for quite a while, welding is the only practical solution I can think of. I've seen a couple different models of the offset manifold; one that is just build on a 45* angle from Custom Motorized Bicycles (being able to use on L or R side) and the kind I bought from Piston Bikes, which is a compound or rising angle, as well as the 45*)

    I will have to try and return this Sick filter as it's like trying to fit a round peg in a triangular hole, even after modifying the intake tubing. I might even have to make my own filter. But, once I get the carb. level, I should be in good shape.....

  4. butre

    butre Well-Known Member

    are those aluminum? I feel like I've used ac stick on one before. maybe my memory is hazy, I haven't looked at a commercially available intake for one of these in months
  5. KCvale

    KCvale Motorized Bicycle Vendor

    Well, I have a drawer full of intakes and they are not labeled, the one I used needed no mods.

    That is a good air cleaner but the low profiles work well too and fit, I'm sure SBP will swap, good guys over there.

    Tough to tell if your engine is at a 90 to the seat post though without a front mount.
    Get the engine and drive train in and working first, everything else is just 'make to fit' if need be.

    I built mine up to running before I even dinked with the gas tank.



    Everything played nice after that, and even that was not hard, the carb had that air cleaner on it and I didn't need to even 'reamedy' the exhaust pipe mount holes to twist it to fit nice.

    Sorry I can't steer you to a BUY link for the perfect Z intake, but most can take some 'reamey' elongation on the mount holes to tweak it's angel a bit.

    The simple little tricks are the best ;-}
  6. PocketBiker

    PocketBiker Member


    Great to hear from you KC.

    I've had a very busy day! I did take my intake manifold to a welder/friend of my neighbor and he was very accommodating, though I have to clean up quite a mess of metal inside BUT..... my carb. is now on the straight and level! Now, I will work on a good air filter choice.... hopefully, I can just exchange it. It was funny though; The welder was expecting aluminum but when I handed it to him, he said this is silver painted steel!:rolleyes7: (I guess, everything silver...... ain't aluminum) :dunce:

    After getting the carb. altered, I got to work on my gas tank. I had already worked very hard, getting the wooden forms just right. That took A LOT of time and thought. (good thing, I love problem-solving) This process might be interesting to some of you. I just finished the foam form a few minutes ago..... so, I'll post some photos. Soon, I'll epoxy it (I just found out that regular fiberglass resin eats this foam) I have the forum guys to thank in an old thread, for setting me straight on that early.

    Here, you see 5, one inch-thick foam boards stacked up in the wooden form ready to be sanded. (not hot wired..... I've spent a fortune on this project already!!!! Sanding will have to do.... (and it did)


    So far, so good....


    Now, for the horizontal shape....


    This is the form for my epoxy/glass fabric tank which will sit inside the mock tank metal, after sealing with the Caswell tank sealer.... Thanks for that great idea KC!!

  7. Arty

    Arty Active Member

    Nice job on the foam!
  8. PocketBiker

    PocketBiker Member

    I'm on the Internet now, taking a "crash course" on fiberglass cloth options. Nothing is easy!!
  9. KCvale

    KCvale Motorized Bicycle Vendor

    Just be SURE that foam slides easily in and out of the frame.
    Once you build it up with fiberglass you'll be screwed if it won't slide in.

    There are two mount bungs on the frame, the ones for the fake tanks mounts.
    I just ground mine off but they are pretty close to where you will want to make mountings to keep the tank in, and don't forget the one on top between the bars near the back.

    Looking good bud ;-}
  10. PocketBiker

    PocketBiker Member

    I built the wooden forms a full 1/2" smaller in height. Mostly, because I want to route the throttle cable up and over the tank, but yes, I can't go too thick on the glass. I'm trying to get a handle on whether I should go with the thicker (sturdier) mat, or regular glass cloth?? The mat is much easier when making the tight radius curves. I'm a bit afraid of those curves because the cloth doesn't like to turn sharply and in two different directions..... leaving pockets of air. Nothing more maddening than seeing bubbles of air in your glass, as a result of the cloth, not laying down properly!

    Yes, I intend to file off the factory mounting bung on the horizontal tubing. (It can't help me) but I'm thinking the upper "tab" might be useful in holding my tank from lateral movement. I'm anxious to show you my mounting method.... it is a very basic idea..... but I think, very solid! :devilish:

  11. KCvale

    KCvale Motorized Bicycle Vendor

    My issue was length, I have to tappy tap the tank to get it to fit.
    It's all metal so that is good thing, for glass probably not so friendly.

    Just take your time but I look forward to seeing what you come up with ;-}
  12. PocketBiker

    PocketBiker Member

    Z Intake Manifold


    I have "buggered" up the offset manifold I had welded and have to just throw it away. You mentioned that you had a "drawer full of them." I don't know how literal to take that comment, but I have to buy another. You mentioned that your stock manifold was just correct, off the shelf?? Wow! I'm dying to find that one! Do you know where you bought it or do you have and extra one (in that drawer) that you would be willing to sell? (The type of welding that my welder used, made a horrible mess inside the tube and it just went downhill from there)

  13. PocketBiker

    PocketBiker Member

    Another Z manifold ordered

    I just found another offset manifold on eBay for $8.50. $11.50 delivered....

    I called the welder and told him, of my problem of my trying to clean up the welded "splatter" on the inside and that a stone I bought wouldn't touch it and he said, "Oh, that's because I used stainless rod." :rolleyes7: Well, duhh!!!!!! So, he agreed to do my next one "on the house" and...... use a cooler welding method. The problem will only cost me time, $11 bucks and several hairs, I removed.

    So, K.C., I won't have to bother you with my request.

    I set my foam into the bike.


    Looks like a lot of tank sticking out in the front, but how else am I going to make it coast to coast, without stopping?!! :jester:


    I'm ready to epoxy/glass the foam, but I just had to tape the sides on..... yep... it fits with room for resin.

  14. Wolfshoes

    Wolfshoes Member

    Why not go with Jaguar's intake extension to level the carburetor.


    Years ago a 2 part epoxy we were using came with fiberglass already in one of the components. If the resin you were planning to use is not compatible with ethanol; there is no law that says you could not use another resin instead like Caswell's to coat the fiberglass matting. Granted it may cost more $$ and be messier than a Eskimo picnic to work with.

    Another recollection I have is of a Jeep hitting the door of a Corvette entering the high school parking lot (many) years ago. The impact of the Jeep bumper put a hole in the door of the fiberglass Corvette. I would bet the fiberglass Corvette had a metal tank.
  15. PocketBiker

    PocketBiker Member


    That's good stuff Wolfshoes! You never disappoint! I bought the 3.25" manifold this afternoon. The welder is "comping" me when it arrives, so we will level the exit tube...... then, I will have the option of either lengthening with the auto hose or not. That was really interesting.

    Coat the fabric with the Caswell? Yes, I'm sure that would be a very good way to go. In the beginning, while I was planning my attack, I didn't realize that the Caswell is really just another epoxy..... strength and all. So, I thought the tank should be made of a high strength A/B epoxy. But, my epoxy and the Caswell cost the same.... so, it would have made good sense to just use the Caswell.

    I did come to the conclusion to just use the Caswell when building the petcock and filler tube areas. Either way, I'm guessing, it will be fine. I'll begin glassing tomorrow.
  16. KCvale

    KCvale Motorized Bicycle Vendor

    Caswel is a 2 part epoxy and as I mentioned Very Unfriendly to play with.

    If you want to get a feel for what spreading it around is like, warm up some maple syrup and try coating a leftover piece of your foam with it.

    The difference is you can wash (or lick) those little drips and strings of syrup off, whatever the Caswel touches it will permanently stick to.
  17. PocketBiker

    PocketBiker Member

    A shot of my solution to what I feared, was a vulnerable (and under-engineered) area for this large, down-tube bike; the front engine mount. The engine was originally designed to clamp around a solid tube, putting a relatively minor amount of stress on the two (small diameter) mounting bolts. But, with a "hanging-front-mount", a tremendous amount of load is delegated to those two small bolts, (and an aluminum case). Perhaps, they would hold up. ("minimal-mounts" are certainly being used) Maybe I'm "Captain Overkill", but I began trying to design a mount with more support (and with the help of JB Steel Stick epoxy putty) it evolved into what you see below.

    I opted for a "beefy" 3/16" thick steel plate, (2.75" wide X 3.5" long) bent in one place (20 degrees) so both 5/16" U-bolts would be at right angles to the down tube. Here, you can see the engine side of the plate with two bolts, which will act as re-bar for JB Weld, Steel Epoxy Putty which will fill the intended, half round void.

    View attachment 56728

    Now, you can see that the JB Weld epoxy putty has cured after tamping it in the half-round void, with the plate bolted on. (The putty insures a perfect fit) Also visible is the after thought of also installing JB Weld support tabs (also molded around one "re-bar bolt" each. Any surface I didn't want the JB Epoxy to stick to, I waxed.

    View attachment 56729

    The plate installed. Now, you can imagine how much support the JB Weld gives. It takes on the roll of the solid down-tube. It's a pretty simple solution and $6, well spent.


    I finished fiber-glassing (with epoxy AB resin) yesterday. Very happy with the way it turned out. I used the 4 layers of 6oz. cloth, bought at Lowes. (The resin came from Polymer Composites, Inc, from Ontario, Ca) I glassed the tank, (4 layers of cloth) in one session, which was very tricky, as I was always working with very sticky surfaces. (Think, a very thick honey) But, I found if I kept working on another side, the wet side would cure just enough that I could finish the tank in one operation. What I liked about doing it that way, is that rather than having to keep rolling out resin, (with a roller that I didn't have) I'd just lay on another glass cloth piece and the resin would just soak into it.... Very cooperative! (Notice, the sticky tank is supported on thin aluminum supports as I worked on it giving it little surface to stick to)

    This morning, man.... that tank is HARD!! The Caswell, will be next, after I melt the foam out.

    View attachment 56731

    After cleaning resin off of my hands, just around midnight, I finished my all aluminum "baffle-box." Originally, I was thinking of just hanging the two baffles from the cut out top of the tank, but it dawned on me that just building a box would be simple, and the most solid design. Here you can see the box sitting on where the cut out will be made (also, enabling me to install a couple of brass gas gauge fittings inside) The box will drop straight down in this position and be pop riveted to the top "door" into those two bent flanges you see here.

    You can see the many 1/2" lightening holes allowing a good oil/gas mixture. (THIS IS A NO FOAM ZONE) :sweatdrop:


    Just visions of the future. Mounting details are a bit hazy, with just a general design in mind.... but it will come together. The worst is behind me.

  18. PocketBiker

    PocketBiker Member

    copied message
    Last edited: Mar 15, 2015
  19. PocketBiker

    PocketBiker Member

    Two added photos

    Well, my last post was being difficult, (I guess with my posting 6 photos) So, I'll show the photos that the page eliminated.

    I opted for a "beefy" 3/16" thick steel plate, (2.75" wide X 3.5" long) bent in one place (20 degrees) so both 5/16" U-bolts would be at right angles to the down tube. Here, you can see the engine side of the plate with two bolts, which will act as re-bar for JB Weld, Steel Epoxy Putty which will fill the intended, half round void.


    Now, you can see that the JB Weld epoxy putty has cured after tamping it in the half-round void, with the plate bolted on. (The putty insures a perfect fit) Also visible is the after thought of also installing JB Weld support tabs (also molded around one "re-bar bolt" each. Any surface I didn't want the JB Epoxy to stick to, I waxed.


    Here is the photo of epoxying the tank on thin aluminum angle supports.

    Last edited: Mar 15, 2015
  20. Arty

    Arty Active Member

    That's going to be a really nice machine! - Your front mount is a real improvement - strong, and good looking.