G'Day from Brisneyland, A'Straya !!

[SteveAndBelle]

Hi all.

Just finished building my first motorised bike using the cheapest & crappiest bike & engine I could find. AU$100 for the steel frame MTB from K-Mart + AU$200 for the 66cc engine kit direct from China via eBay so all in all a bit of a bargain for a few days of continual installation challenges (aka: holiday entertainment) and a bit of fun transportation ;)

Anyhoo, the bike frame was VERY restrictive. I measured it up in the shop and it all seemed OK however when it came time to attach the carby and install the spark plug it was a different story. I'm a computer dork by trade so I'm not exposed to this kinda stuff much but after a quick trip to the local hardware store where I bought $3 worth of copper plumbing fittings, some thick solder and a blowtorch I managed to modify the intake pipe with an add-on 90 degree bend so I could mount the carby out to the side. Unbelievably it worked perfectly straight away ! I was amazed ... and kinda proud of myself. I then had to solve the spark plug problem because the supplied 'Champ' plug was far too tall to fit. Went back to the hardware store knowing that stubbier plugs were available and bingo, I found the perfect drop-in replacement which gave me more clearance to the upper tube of the frame so I was even able to use the large bulky & somewhat dodgy looking Chinese HT cap. Again, it also worked perfectly first go. Brilliant :)

So, I'm still half a tannk away from finishing the run-in period but I'm happy with the results so far. This site has been the best help and I've now also learnt all about '4-Stroking' which is something I've been concerned about when at high revs. Yeah, I know ... mixture too rich. I'll use up the remainder of the fuel and give it a run with the standard 50:1 mix for a while before I start fiddling about with leaning it out any more than it already is. I've checked the spark plug and it's got a great beige/grey colour to it so I know it's running well ... I just hope the '4-Stroking' will naturally fix itself after the run in but if not it'll be 'E' clip time :)

So yeah, this moped isn't a patch on my beautiful 1980 Motobecane Mobylette 51V I have safely stored away at home BUT it's been a heap of fun so far and I look forward to a lot more as time goes by.

Thanks & seeya 'round !

Steve.

[SteveAndBelle]

OK, I can't post links or images or anything yet ... so here's message Number 2 ...

[Evan]

G day Steve and welcome. Post us a pic of your China girl. I'm sure we would all like to see your mods. Have fun
Evan

[SteveAndBelle]

... here's message Number 3 ...

[SteveAndBelle]

... and hopefully I can now post links ?!?!

[SteveAndBelle]

Now that I've posted my first 3-4 messages I ahould be able to add some links to pics etc. Worth a shot anwyay ...

Here's the intake pipe mod I made: http://i175.photobucket.com/albums/w.../IntakeMod.jpg and here it is fitted to the engine with the carby attached: http://i175.photobucket.com/albums/w...akeCloseup.jpg

Here's a shot of the spark plug after half a tank of 50:1 'run-in' mix: http://i175.photobucket.com/albums/w.../SparkPlug.jpg

Here's a shot of the bike after a 15-20km trial run literally only seconds after I finished tightening up the last screw: http://i175.photobucket.com/albums/w...5-20kmride.jpg

... and here's what she looks like now being started & ridden by some girl I know: YouTube - DIY Motorised Bike ... just like all the others.

Seeya !

[SteveAndBelle]

YAY, it worked

[SteveAndBelle]

Now I can start on my 2nd identical bike & engine kit but this time I'll try to cut the intake pipe back a bit and modify it with slightly different copper pipework so the carby is closer to the engine.

Reckon that would actually make any difference or does my logic not count in this area ?! I thought the easier & smoother the path the air/fuel mix has to get to the combustion chamber the 'better' the engine would run ... right ? Adding my 90 degree copper pipe mod would surely add some resistance to that path and decrease performance a smidge ?!?!

Maybe I need to experiment with my electric turbo theory I assume you can get better performance by forcing air and a richer fuel mixture into a 2-Stroke the same way it does for a turbo induced car engine ?!?