MOPED ARMY

Part Deux

So after deciding that it’s not safe to play with cars that are capable of rolling over me even at my 24mph top speed, I decided it was time to get serious with some power improvements. Well actually, in truth, I just have a bad habit of ploughing money into modifying cars, and even though it’s only 2.5hp, the Motocompo hasn’t escaped the same attention!

There is a fella in Japan that hand builds expansion chambers for these critters, which are claimed to yield a 6mph improvement. The only downside was the cost, which at USD$300+ makes them a little bit pricey. All the more so when it arrives on your desk at work and you discover it’s barely larger than your keyboard! So after a few weeks of procrastination, I found some time to fit the pipe, and made the effort to wrap it in exhaust header, since even the standard mufflers are known to get hot enough to melt the plastic fairings.

Now, with no other changes to the bike I was able to pick up 8km/h (5mph) on the top end to increase to 46km/h / 28.5mph. It is worth noting that my tyres were definitely a little flat due to sporadic use, and so I think I could have hit 30mph had the tyres been properly inflated. I have since pumped them, and so will do one more run to confirm top speed before moving onto the next phase of the project.

For the next post I’ll also include some pics of the Vapour Trail Tech that I installed to keep an eye on all systems, plus update on my 70cc plans!

Cheers for the love.

Outwardly I want it to appear pretty much stock, except for the hint of the expansion pipe, and the Trail Tech on the nose. I'm certainly not planning on any of the craziness that the Japs do with extended swing arms and monstrous tyres etc! However, I still want it to go like a scalded cat :)

I'd love to hit 40mph and call it a day. I bought a bunch of stuff from Treats a while ago, including the Polini 70cc kit, and Malossi intake manifold with Dellorto 21 PHBG carb. I'm actually building that on a 2nd chassis I acquired, which will be switched across once the time comes. (edited)

Yeah on the 8" tyres it's more like driving through a pothole rather than over it! I'm not planning to get on full throttle everywhere, but just to have that extra speed in the back pocket would be nice to have.

Us non metric folks also say tire rather than tyre. Cool beans on the bike!

WOAH SICK!

thanks for posting, i won't even bother with the WFFF because in US its technically a scooter.

is it an 'express' powertrain? Variated? single speed?

Commenting to follow this thread. This shit is already rad as hell.

hell yes, make it happen capn

Into it

Thanks for all the appreciation guys. I'll update in proper over the next couple of days as I recover from the flu. In the mean time, a snap from Saturday's run. That equals exactly 30.07mph!

Will chime back in soon.

Posting to follow this thread. This is exactly what I want to see happen to a motocompo

Ken's a good dude but he's not gonna be happy until you're using a performance mesh filter

...

Part two of the experiment was to be a back-to-back test under the same conditions, but with the dual stage Boyesen fibreglass reeds. As you can see from the pics, it seems the flaps open first under low revs, with the big windows opening up under higher revs. After blipping the throttle, the response is noticeably more crisp. With hopes high, I rode back to the same spot that I managed my 30mph run, but then had the misfortune of overestimating how much fuel I had on board, so ended up pushing it back 2 miles to the nearest gas station. And that is where the experiment ended.

On the upside, my 70cc assembly is close to being ready, so I was not going to delve any further with this setup, however, Ken has piqued my interest in what that pipe might be able to achieve with proper jetting, so I am now contemplating an intermediate stage of attempting to tune the Dellorto to the 50cc setup first, to quantify the difference it makes. Once the 70cc is ready, it would then also give me an idea of whether the overall improvement is coming from the extra capacity, or the better carburetion.

So in summary, the planned evolution will probably be: Factory 50cc (24mph) --> 50cc + Pipe (30mph) --> 50cc + Pipe + Reeds (top speed TBA) --> 50cc + Pipe + Reeds + Dellorto --> 70cc + Pipe + Reeds + Dellorto.

"back-to-back test under the same conditions"

we need to do this more

Graham Motzing Wrote:

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Specs as per your request!

It occurs to me that I haven't posted any pics of the Motocompo with the vehicle that is tasked with carrying it, - my Honda City Turbo II. It's a last of the line model built in 1985, in which Honda finally ditched the questionable all blue interior and went with a more subdued black. Together, they're an awesome pairing.