Kimjon

This is the brake set-up on my one. I didn't make this, it was already done by someone else. I wouldn't say it's in the league of Brembo's 6 pot calipers on a super bike...But it is a lot better than nothing. I'm sure I've got a few of those brake discs floating around you can have for nothing. And the calipers are like $6 on ebay...or if you don't wanna wait 6 weeks you can get them for $10+ postage on trademe.

It was only a matter of time...

Like all compulsive disorders, it just creeps up on you until one day it gets too hard to deny it anymore. That line was crossed years ago...

Yes! Yes, yes...Yes!!!

Sounds great thanks! I'm in Cambridge if you're ever up this way? But if you get the urge to do something with it yourself, or just want it gone and need to dump it...no hard feelings:)

Those motors go well. Either 33cc or 49cc, both look the same. Always keen for another project, whereabouts are you?

Ordered 4 new tyres with tubes online. They arrived today. Un-boxing stuff that arrives in the post is a guilty pleasure of mine. Even though I have a pretty good idea what's going to be in the box...it still feels like a little present to myself that I'm unwrapping. Wheel off... new tyres on...boom! Mint as!!! These new tyres are so much better in every way possible. Slightly smaller diameter gives better acceleration and they are perfectly round and ride much truer than those shit sack trolley tyres ever did. Success!

Small set back, I found a broken stud in the little G23LH motor. Luckily for me I brought a frame for spare parts a while back...by chance it had half an engine lower case stuck on the frame! Seriously what's the odds? It was in terrible shape. But using some trusty oven cleaner it scrubbed up okay. The bearings are fucked, as too are the oil/crank seals. I'll go to seal imports and get new ones. So with that setback sorted. I thought while it's apart...may as well port the fuck out of it! So I did: I always label my halves left and right. Plus draw the crankshaft rotation on as a reminder. The black is bad. That's about as dumbed down as it gets. So basically the blacks gotta go. It causes restrictions and ruins flow by creating eddies and turbulence. Note how badly the ports are mismatched...basically the air/fuel charge is hitting a wall! About 25% of the port is blocked by this sharp edge. So, to speed things up I'm using a milling machine to rough out some larger parts. Also I milled the skirt down on one side by about 2mm all the way around. Then it's time to rough out the rest with a burr in the dremel: Roughed out. Now time to tidy up a little. Below is a great before and after shot. Before. Note the sharp shelf and edges. Very bad for flow. After. All edges now flow and transfer ports opened up and port matched...much better. Finally. Here's a good side by side comparison of the cylinder. Look how much bigger the transfer ports are on the right hand (ported) cylinder...at least 50% if not more. That should flow way more air/fuel. The exhaust will get polished. The intake will be roughed up a little. But no real changes other than port matching the exhaust and intake will be needed as the specs for port timing are already very good. Only small wins could be made at the risk of ruining the motor. I'll replace the bearings and seals...slap it back together and it should be way better than before.

Yip! Sure is. It's not quite in tune yet, and I want to experiment with closing the hole down a bit on the pipes exit, as I think I'll make more back pressure and that could be beneficial? Here it is parked up with some of the fleet;) Sad thing is there's many more to come...

Yes...yes it is! Finished. 49cc of stupidly fast goped!!! It's slipping on the wheel a bit, as the wheel is worn-out and has become egg shaped. However that is genuine wheel spinning power your witnessing in that youtube clip. Seriously when in powerband it spins the rear wheel! Yeah buddy...it rips!!! Wheel spinning goodness. This hard tyre goped is awesome! Back to basics motorised fun!

I added a cam locking device to the axle. Basically it supports the axle and prevents it from moving under the weight of the rider and braking the crankshaft. It's the purple thing. I drilled a hole and put a pin in it. The purple thing (called an EPW..."engine protection wheel") is then pushed around until it locks in an appropriate tooth on the wheel.

Fuel tank mounting was the order of the day. Im a sucker for milti purpose brackets...way to much time spent watching "project binky" on youtube. Anyway this is my solution to two problems. 1) hold the gas tank 2) cover an ugly hole left where the original motor was mounted. These things literally grind on the tyres. ..making lots of fine rubber dust that goes everywhere if given a chance. So blocking this hole was a essential. Here's that big hole on top. And hole blocked...plus strong bracket mounting for tank. And that basically completes it.

Righto...this shits getting real! I re-made the drive spindle. Using some basic maths I was able to figure out the taper angles and grind a "one off tool" to bore the hole. I then chased this up with a boring bar to get it bang on. For those who have never seen a knurling tool in action...Here's a quick video: Spindle mounted to the motor. Next up was to sort out the brackets for the expansion chamber support. That's all squared away now. Up next I mounted the motor and used loctite on all the fixings to keep them in place. The observant among you will also notice it now has a rear wheel. I stole this off my next project (the white goped). Kill switch and controls where some easy wins: I basically copied what the old goped used to have. By drilling and tapping a hole on the handlebars and fitting a kill switch. And the controls where left over bike parts modified to work. The gas tanks for these are extremely expensive! Like $50...plus postage from the USA. So I brought this tank off ebay for about $5 delivered to my door. The carburetor I'm using is a diaphragm type, or pumper as commonly called. They pump their own fuel and require two fuel lines. A feed line and a return line. So: Easy fix. Cut off the one outlet...drill it bigger. Make another hole beside it. Tap holes in 1/8" NPT. mix up some permaseal fuel resistant epoxy...bung it all together. And that's a days work done!

I made this one nicknamed the "slo-ped". I used a 20cc weedeater motor of very unimpressive port design from the factory. As you can imagine it wasn't nicknamed "slo-ped" for no reason. However it worked well enough for a bit of fun. It did however look tough if nothing else! And that's the look I'm imagining for this new project...black and white...tough!

Yip...yip...yip... Absolutely loving the white paint. I'll sandblast it clean...then paint it white again. Give it a severe porting job, bigger carb, make an expansion chamber and general tidy up...then ride! Well that's the plan.

Thanks. I geeked out online searching the pros and cons of wrapping an expansion chamber. Pros: basically none. Only benefit for me is avoiding 3rd degree burns. Cons: keeps heat in, will cause premature rusting. Has potential to change the pulse wave adversely due to extra heat. Then I found someone online who's experimented with a dyno. His conclusion was as long as the first few inches on the header straight out of the motor weren't wrapped. It didn't really change things all that much...so do it if you want too. Using my usual way of Internet researching, as soon as I found someone offering the answer I wanted...I stopped looking. It's got to be true;)

I thought the colon needed to be wrapped. Not for performance...more for not wanting to burn my fucking leg on it, if by chance I touched it. And installed for a cheeky look Next I'll make a supportive bracket to, ummm, well, ummm...support it?

Drive belt arrived. I worked out the length using some 7th form mathematics I kind of remember. I then had to order the closest thing to it size wise. Problem is my maths was in between sizes available. So I went bigger. Logic been worst case it should still work versus not fitting at all. My remote oil filter is a bit close to the belt. But I have an easy solution for this. I'd like another 5mm of clearance to avoid potential issues.

Driving it like you stole it! Excellent

Expansion chamber done. This was tricky, welding such thin and contaminated steel. One moment you'd be welding like a Jedi master...next a huge hole would blow through! Then it's the fill the hole game again...

Yes

Lotto ticket time! Just road it down the road and back at full throttle...didn't even notice until I parked it up. I had on my usual safety PPE of jandals and no helmet. Think I just dodged a bullet by about 30 seconds?

Come on...where's the drag racing street outlaws video: "death-ped V's mobility scooter"?

Fuck it...I'll rest when I'm dead! This will definitely work. But I'm now considering a variation on this with a longer spindle that is supported by a bearing. This isn't a new idea...been done many times before by others. The drawback of the bearing is its a parasitic loss...ie the bearing will rob power from the little motor. The positive side is it may save the crankshaft from braking! I've smashed a crankshaft before...so I'm always a little gun shy with these. So yeah/nah....let's do this again...but better.

Picked up some aluminium scrap. I struggle to get materials some days...but got lucky. Turned it into this adapter plate. There's method to the madness of all those holes. Each has a purpose and a special way of going together. Then I notched the deck some more. I needed even more clearance around the carburetor. Engine mounted on adapter plate. It will be direct drive via a friction drive (spindle). I'll make the spindle later on the lathe...but for now I can carry on as I know this part will work as all my measurements are based off a centred datum. This pile of bits gave me an exhaust. I started with a KTM 300cc 2-stroke expansion chamber...and just started cutting...and cutting...and cutting... And that's it for the morning. Remainder of the day is for relaxing now:)