Oldsalt's Caper Cycle. Custom Modified Class.

[Oldsalt]

Sorta late to be entering the Great Mini Bike Build Off but I have more time for such things than most folks and feel I have a chance to complete it in time. Have posted a number of threads in Engines and Modifications in the past several weeks that have to do with Cheap Modding an Intec 190 engine. Yesterday I acquired a Caper Cycle. They are tiny as mini bikes go and originally carried a 2 stroke engine but the Briggs Intec will fit nicely. These bikes were built by Ben Hunt Manf., here in Walla Walla, Wa., behind Mr. Ed's cafe. Real small town stuff.

The engine mods will be briefly reinterated in this thread. Attached photos are of the completed Briggs Intec and the little Caper Cycle as I found it [for $50]. The engine is surrounded by stock Intec parts that have been replaced by Animal parts and etc.

 

[Oldsalt]

Needed an adaptor for the new 22mm carb. Wanted to make an adaptor that would bend to point the intake more toward the rear. First turned a "spool" from a block of aluminum and bored it to size in the lathe. The ends where then cut down and the bolt holes drilled/tapped. One picture shows the spool cut into segments so the the desired 40 degree bend could be accomplished. The part was then welded up and ground/sanded to a reasonable contour. I have a feeling that some one sells this item but I'm cheap.

 

[Hent]

excellent job oldsalt.

sometimes its not about being cheap, its just about doing what you want on your own, and it turned out awesome!

 

[richs]

looks good:thumbsup:

 

[VwDrvFnd]

Thats Beautiful!

 

[offroadwhatever8]

Wow man thats great! That intake looks damn good!

That bike is really nice and simple, I like it! It reminds me of my cat when i first got it. mine came with a lawn mower throttle to :blink:

 

[Oldsalt]

Wow man thats great! That intake looks damn good!

That bike is really nice and simple, I like it! It reminds me of my cat when i first got it. mine came with a lawn mower throttle to :blink:

I like simple too. The little Caper is going to get a scrub brake and hopefully a thumb throttle if I can find a nice one....simple stuff.

Getting ready to build your own frame?

 

[Oldsalt]

Last night the frame and forks and rims and etc. were put in a plastic tub with hot water and a lot of lye. That really cleans things up without a lot of hassle. This morning the engine plate was hot sawed off the frame. In one pic the serial number can be seen...325. Went to see a friend that also owns a Caper Cycle. It's engine plate was also made of diamond plate. His serial number is 386. I then skip welded on a 10 ga. plate on top of the engine plate to cover all the useless slots that are there. The last pic shows the new slots, to fit the OHV Briggs engine, being milled.

 

[offroadwhatever8]

Getting ready to build your own frame?

I am one of these days. The plan is to build a frame and fork's thats not exact, But around the dimensions of my cat. Reson being is that i like small bikes. Ive riddin bigger sears mini bikes, But i just like how little my cat is. Unfortantly, Ive got so many projects goin on right now, That i dont think I'll be getting to this one very soon :doah:

btw, It's lookin good so far :thumbsup:

 

[Yellowhand]

Here's a classic example of why it's sometimes necessary to 'chop' vintage minibikes...

Diamond plate makes a horrible engine mounting plate material due to the uneven mounting surface...it can cause warpage of the engine block...

It may have sufficed for the gutless little gasper of a motor that the Caper came with from the factory, but it certainly wouldn't have held that Briggs in place...

Nice work on that replacement plate...

I can't wait to see some more progress...

 

[Oldsalt]

Yellowhand is right. These Caper Cycles are really crude. I know why they used diamond plate for the engine mount...The Ben Hunt shop made thousands of pick-up bumpers. They were utilizing the drop-off of diamond plate, used extensively on the bumpers, to make them! There is still some arc rod slag on some of the welds. The frames are way too light, mostly 3/4 tube, to resist metal fatigue. This frame shows two frame brakeages ane two repairs. But I love it anyway.

Today the velocity stack was made. Also the jack shaft bearing mounts were made and installed. The first pic shows a piece being cut off a block of aluminum. Didn't have any round stock large enough in diameter. The second pic shows the piece with a rough sketch of what I wanted the stack to look like. I can't make anything without a sketch, even simple things. The third picture shows the rectangular block has been turned down to approx size and a file used to get the final shape on the outside. The interior was hogged out and it too was finished with files and emery paper. The last pic shows the velocity stack in place. There is some more work to do to get it properly attached. Also in that pic you can see the new jack shaft bearing mounts. I am aware of the fact that I am blessed with the ownership of a lathe. That is possibly the reason I dream up silly thing to do with it, such as a velocity stack. I am not worried about air filtration. I recall Offy motors in midgets that sported open stacks. As a curious boy I asked why there was not at least a screen over the stacks. The engine builder's answer was "That only keeps out dead birds and gravel".

 

[Frank Bullitt]

I wish I had a lathe!

 

[offroadwhatever8]

Great work!

 

[jimh]

Looking good. At least your stack fits. I made one like that for mine,with lack of forethought.:doah: Looks like the ones I ran on Triumphs. With the flathead, it won't fit in the frame. guess I'll use it later.

 

[Oldsalt]

Looking good. At least your stack fits. I made one like that for mine,with lack of forethought.:doah: Looks like the ones I ran on Triumphs. With the flathead, it won't fit in the frame. guess I'll use it later.

Don't feel bad. I had to relocate the engine to make mine clear. If I get in a hurry, and don't make a sketch, I'll screw up everytime.

 

[Oldsalt]

Today I made a megaphone for the exhaust system. The first thing was to get a piece of fire wood and turn a mandrel. To get a taper the wood was centered on both ends and put on dead centers and driven with a dog. The tail stock on the lathe could not be off-set far enough to get the taper needed so a dead center [a junk one] was cut in two and the tip moved over about 5/8" and welded back on. See photo. Then a piece of 20 ga. galvanized was hacked into about the correct size and "chatter" brakes made to get it shaped enough to put on the mandrel and secure with hose clamps. More trimming to size and a quick and dirty weld made. Didn't bother to sand off the zink beforehand...should have. The cone was then put on the mandrel and each bend lightly worked with a sheet metal hammer until the pronounced ridges were reduced as much as possible. Then the remaining inperfections were sanded off.

Next will be the pipe. This megaphone is just to make noise and look evil. It will not enhance performance. But I'm beginning to think that the short wheel base bike will be dangerous even without more HP.

 

[Qucifer]

Nice job. Is it for looks, or does it help with performance?

 

[Oldsalt]

Nice job. Is it for looks, or does it help with performance?

Probably hurt performance. First of all it limits the length of the straight portion of the pipe. That is not good because the straight portion would be too short even without the megaphone [unless the pipe stuck out the back of the bike a rediculus amount]. The megaphone slows down the stream of exhaust gases because it gets increasingly larger in diameter. That is unhelpful in this case. But if memory serves me right it will make cooler sounds and the neighbors will hate me even more. Which is good.

 

[Yellowhand]

That's some amazing fabrication...

A velocity stack made from square billet...unbelievable...

I think the jackshaft mounting plates you fabbed will help considerably with limiting frame flex...

When starting off from a dead stop, those higher-torque engines really try to shorten the distance between the engine and the rear wheel, either by flexing the engine mounting plate or the lower frame rails back to the axle mounts...

I've seen a few that flexed more than two inches...

Stiffening the drivetrain platform, like you've done on this bike, really eliminates having chain problems later...

It's startin' to get scary...

 

[Oldsalt]

Ya. You are definately right. That 3/4 tube frame is going to flex big time. I believe the cleanest way to boss up the lower tubes between the engine plate and the plates the jack shaft mounts to is to turn the frame over and cut 3/16 wide slots in that area and insert 3/16 bar. Otherwise disaster will rear it's ugly head. This mini bike frame was screwed over numerous times with half hearted repairs that it is now unrestorable. Everything except the top tubes and the forks would have to be replaced. I am actively looking for a restorable Caper Cycle. But tey are really hard to find even though I live in the town [Walla Walla WA] where they were made.