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Kimjon's not as cool or epic as Muncie's off-road goped Bigfoot scooter thingy


Kimjon

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1 hour ago, Muncie said:

Where'd  you get your parts from? In need of a proper fuel tank.

Daves discount motors. Freight was $50USD... but spread over the total cost of the order it was still a "cheaper" way of getting exactly what I needed/wanted.

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I started assembling motor to final stage.

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Carbon fibre reeds. I swapped over my custom made reed block.

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Walbro style 15mm pumper/diaphragm carburetor and my custom manifold. This converts it to pump its own gas from a tank mounted below the carb, rather than gravity fed like the original. It also allows for more tune-ability (yes I know that's not a real word).

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Lightened flywheel, new coil and modifications done to the spark plug lead.

 

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Then I made custom exhaust gasket to match the new porting.

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And wrapped the exhaust header in fiberglass exhaust wrap. 

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I soaked this in warm water, then wrapped from the thickest end down. By soaking and wrapping it wet, it will shrink tighter onto the exhaust. And by wrapping thickest part and working down to the skinny end it will prevent it from unraveling. Once done, I tied it of with stainless steel bands.

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Wrapping an expansion chamber is normally a really bad idea. Trapping heat changes harmonics/air densities and is known to decrease performance. However burning the fuck out of your calf muscle is an even worse idea than losing a tiny bit of theoretical performance...So being pragmatic, I opted for self preservation.

I only wrapped the header though, not the entire pipe. Seams like a fair compromise.

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8 minutes ago, Muncie said:

I've acquired another stock electric scooter which will get the 2 stroke treatment nothing compared to this though. 

Watching your build eagerly now I'm out of action.

Sounds good. Be keen to see what you come up with, as clearly imagination is not a limiting factor for you :-)

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It the meantime I decided to machine the head for better squish. I found two slightly thicker copper gaskets, then shaved the tiniest amount off the top of the cylinder barrel. My OCD just couldn't rest knowing it wasn't right.

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Then I fully assembled motor including exhaust, "torqued the head down" (i.e. turn hard until it felt about right :-) ) measured squish... and got 0.73mm. So very close to the 0.762mm (or 0.030")... happy with that, so it's going to stay like that.

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Then assembled the rest of the accessories and exhaust. Is now 100% ready to run/test. Boom!!!!

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2 hours ago, Mof said:

Could you not do a heat shield rather than wrap?

Yes, but way more work :-)

1 hour ago, Muncie said:

There are advantages keeping heat in ya pipes I couldn't recall what they are right now. Heat wrap done done right looks sexy anyways. 

For 4 strokes, keeping heat in the pipes and out of the engine bay is a good thing. However for 2 strokes where you scavenge some of the air/fuel mix back from the exhaust system the cooler the better, as hotter air takes up more room (less dense) and therefore potentially losing power.

The amount I've wrapped won't really have a huge bearing on power (loss). And its going to prevent third degree burns to my leg...and it does look cool :-)

So if coolness factor like stickers add +5hp, then that would surely offset real world loses?

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I was advised the stock tiny little HT lead (spark plug) doesn't transmit to well at higher rpm's.

The solution is to remove it, and replace it with a larger non suppressed lead.IMG_20180219_184700.thumb.jpg.97ba305e6525eb344dd54257e9f5998b.jpg

This was a dummy fit on a dud coil to see if I could do it. I used a linisher to reduce the OD of the larger HT lead to fit into the white socket. On the real deal, there's a rubber boot covering it.

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Spark plug connector installed. Once again there's a rubber boot to go over it.

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Finished.

 

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Here ít is finished. Gone from about a stock 5mm lead up to about an 8mm lead.

Also while I had it apart, I installed a grommet and re routed the kill switch (wire to ground the coil, to stop the motor).

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This looks a lot tidier. You won't see it once motors back on the frame.

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Pictured above with new modifications.

 

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Waiting on frame, so trying to do all the little things. I brought a new gas tank, so made this sexy bracket to secure it to the goped:

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Roughed out, and next to the old bracket. I want it to sit flat, bringing the tank closer in. The old bracket was bent to clear the wheel...but someone put a huge sprocket there :-)

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Finished.

 

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My wheels looked like something Jacques Cousteau found at the bottom of the sea. I forgot to take before photos, but they were near bin material...however new ones with tyres and tubes would be approximately $300 landed. So refurbishment was the only realistic choice to keep the cost down.

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I stuck the rim halves in the lathe and used sand paper to knock them back into shape. Then etch primed the centre's.

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Then I hand painted the spokes to try make them look like mini Simmons mags. I was going to go gold...but pussy'd out and took the safe road - black.

For tyres; the wheels on hand trolleys will work. My tyres were 3.0-4 and the sack trolley tyres are 4.10/3.50-4. Both are suitable for 4" rims, but the sack trolley tyres will be slightly taller and wider. But considering I have some already...free!

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Next up, lightening up the clutch.

I want to adjust the engagement to occur at a higher a rpm. By going from steel to aluminum, this will help.

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Drilling out some holes to remove weight from the arms will further help.

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And while apart, I polished the ends where the springs rub to reduce spring fatigue.

This will be a bit of trial and error until I get what I want. It may see the drill again for more removal of metal.

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