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Discussion Starter #1 (Edited)
Hi everyone. I've built things from motorized bikes to electric cars and I have a scooter project I'm designing that uses a pocket bike engine. Whatever this engine was originally designed for (string trimmer most likely) it had a cylinder cover and a gas tank. Also a muffler and cover. You can see them in the images below. If you look on your motors you'll see 2 aluminum "pegs" sticking out just above the crankcase on the flywheel side and 2 threaded ears on the clutch side. This is the gas tank mount. Your plug boots are also made to fit the cylinder cover which is usually missing on the pocket bikes as well. That's why they seem goofy looking because all the pocket bikes are missing the cylinder cover. The image of the engine on the skateboard is what that engine would originally look like, including the carb cover, before it fell victum to China's pocket bikes.

Can someone show me where to buy this engine with the cylinder cover and gastank? Or where I can buy the cover and tank seperatly? Or tell me the original application or manufacture and maybe they have the parts.

I figured if anyone knows, you guys would. Thanks.



 

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I've seen a few bikes come with the cylinder cover but the gas tank is something i've yet to see, interesting to see what the engine used to look like though and I hope someone on here will have an answer for you because i'm curios myself
 

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Discussion Starter #3 (Edited)
It's driving me nuts too because I was a small engine mechanic for years and the more I look at it the more I realise I've worked on that motor in the past. I was thinking an old 80s Homelite brush-cutter. :confused: I know I've seen it before. The engine mount holes held something like a wire loop that served as a stand. Maybe that's why they're not machined worth a $hit because it didn't matter much on a trimmer. :rolleyes:

EDIT - Getting warmer. "Maruyama" brand string trimmers is one of them. Herer's another one selling them. http://www.chanpinw.com/en/ProDetails.asp?ID=50

EDIT - Engine model may be "1E47F" BRUSH CUTTER 1) Model: TJ-47RB (Robin model) 2) Engine model: 1E47F http://www.manufacturer.com/product/i5677302-Brush+Cutter+47cc.html



 

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Discussion Starter #6 (Edited)
I mocked up a tank off a weed whacker on my prototype but I need a more permanent (and cheap) solution. Finding the manufacturer of the engine with the tank would be easiest. That or make part of the frame my gas tank but I'm not fond of the idea. I could use pocket bike tanks but that requires extra brackets to be made and welded to the frame. For a one-off that's fine but in production those steps add up quick.

 

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There you go, make your own stuff thats what I do.
 

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Discussion Starter #8
There you go, make your own stuff thats what I do.
:):thumbsup: Absolutely. This thing is more stable then a scooter and more comfortable then a pocket bike. Does about 25~30mph with stock pocket bike parts and is a blast for effortless wheelies and tricks. I'm looking into some engine mods for just a little more torque. Top end is ok. Aside from a pipe (limited space), what's the best bang for the buck to get more low-end torque while maintaining the same gear ratios? Any suggestions?
 

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Take the base gasket out and put a very thin layer of Yamabond in its place, set back down, put the bolts in finger tight, let is 1/2 hour, tighten them down, more compression, more power. Put a rocket key on the flywheel/crankshaft, a good carb and a HP exhaust.
 

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Discussion Starter #10
What carb would you recommend? Looks like quite a few out there. I was going to port match the exhaust too since I made the flange out of 1/4" I can sort of funnel it into the pipe.
 

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Cool Build!

For the carburetor, you may want do go with a "Pumper" Carb,
since the fuel tank is so low, not allot of pressure is gonna be able to build up.

Some of the Walbro's are really cool!

Good job and keep up the GREAT work.
 

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If you get a pumper carb, its just a chain saw carb, WT813 Walbro, $45 at Dave's but you need an Int Manifold $20, throttle arm, cable holder $7.50, have put the return line back to your tank, so a $6 2 line set, an $8 V-stack and $15 HP air filter. It don't bolt right up, had all kinds little problems. Better if you pay $70 at SP4L for a WT603 copy carb kit and it comes w/ manifold to hp air filter. Then you need a new exhaust for the bigger carb to breath, racing springs, 3 bearing clutch housing, Pretty Cheap at hkmotos.
 

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Discussion Starter #13
Thanks NaSa. I'll have to relocate the tank higher and see if that's whats causing the bog at high speed. I can't imagine this engine using fuel faster then it could flow out of the tank. Which is pretty quickly when the line falls off. >.< -doh-

EPR - I need to stick with cheap and easy bolt-on solutions, if I make any changes at all. Maybe a larger bore version of the stock carb? Or bore the stock one myself? I haven't read up much on those results.

I'll have some video footage soon and hopefully get it into production by next month. I have a chain issue to figure out. It's probably going to need an idler.
 

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Thanks NaSa. I'll have to relocate the tank higher and see if that's whats causing the bog at high speed. I can't imagine this engine using fuel faster then it could flow out of the tank. Which is pretty quickly when the line falls off. >.< -doh-
No Problem! :thumbsup::D:thumbsup:
 

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I have a bunch of taper bored stock carbs. I sent 2 new carbs, to Boosted306, Sam. for $20 each he swirl tapered the front to .750" and the back from 12 to 14mm, then its rejeted & set. Both of mine bolted right up & went to work. Running one on a HP B/B FC crank motor I put in my A2 Cag., have to have my 130lb son to set on it so it down come off the ground when you start it. The other is in my A1 with one of the two Sam's 3rd Stage Billet Head B/B Kits, his swirl bore carbs work very well.
You can only go from .510" to about .565" on the carb bore, 9/16", the walls are very thin, need a milling machine w/ end mill cutter.
 

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Its made for a piston port engine, like the engine in my avatar photo, have 3 or 4 of them 15mm carbs in a box. Also have Cag manifolds that fit it to a Cag. I put a $33 WT813 Walbro And made a billet alum intake manifold from a GS40 manifold.
 
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