Super Stocker build

GoldenMotor.com

Moto

Member
Jan 7, 2012
403
15
18
San Francisco, CA.
hello

I swore off motorized bike a while ago, but saw this 50cc kit for $99 on ebay and couldn't resist.

http://www.ebay.com/itm/Silver-Moto...ash=item2361a4b9df:g:znwAAOSwUV9Wpbnl&vxp=mtr

It arrived a few days ago and to my pleasant surprise was a cute little 50cc round head engine. The kit was decent, a slightly strange 'speed' carb. Casting on the engine inconsistent - head and case very good, cylinder terrible. Casting on clutch lever absolute ****. nice chrome exhaust. Nice tank, overall finish on parts the usual.

Stuck it on my previous motorized bike frame. Rear wheel has a disk-sprocket adapter, so dont have to deal with the rag joint disaster.

Trying to keep this bike nice and stock. Excuse the mess it is right now, will clean up and repost progress. Also chain tensioner will be removed. Hopefully this will be a smooth little runaround bike!
 

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Jan 17, 2015
591
21
18
ca.
Lol..know what mean...i said "no more"....went to the swap meet...dang if there wasn't a Honda g100, 2.5 hp...it followed me home!
 

Moto

Member
Jan 7, 2012
403
15
18
San Francisco, CA.
chain guide

this build is coming along nicely

rides pretty well, maybe 30 mph with very little vibration.

Ive always been sketched out by where the chain goes into these motors, seems like a recipe for disaster. Built a guide to make sure the chain is always going in smooth and aligned using some old cutting board material and an aluminum plate. Hides nicely behind the chain guard and looks unoffensive. Inspired by:

http://arrowmotorizedcycles.com/shop-now---case-saver-chain-guide.html

but free to make!

Also welded up a little exhaust, nice to finally have a power band.





hidden away:





For an improvement I think the chunks of plastic can sit much closer together, but I was trying to have contact with both the bottom chain as well as the top, hence they are more spread out. It would be easy to move them around and I will experiment with what works best. Chain is definitely more quiet now and just waiting on a slightly bigger sprocket before I ditch the ****ty stock tensioner. Feeling solid!
 

ZipTie

Active Member
Jan 8, 2016
750
82
28
Mpls Mn
Liked your build and the chain guide. Yes the tight space in the sprocket cover like u said is a disaster in the wait/ My son found out fast thank goodness he was going slow when it happened, scared him is all and rear tire did a skid. Those bolt bosses on the inside of the cover can cause instant chain lock if the chain goes slack for any reason. His slack was caused by a stretched out tensioner spring that was complete junk from the manufacturer. Not sure what your guide will do but believe it may help stop the dreaded instant chain lock up. Keep us posted on its performance and if you tweak it. Good looking exhaust too.
 

Moto

Member
Jan 7, 2012
403
15
18
San Francisco, CA.
tuned a lot today. This has got to be the thirstiest chinese engine I have ever come across. #85 jet on a stock engine, stock intake and nt carb with a pipe. Pretty weird, but runs really good. Gas Guzzler :) Plug still looking a little ashy white so may need to go even bigger on the jet.





also got a new rear wheel, old one had a really bent axle and cheep-o single wall aluminum rim. New ones a lot more beefy and lighter too.
 

Moto

Member
Jan 7, 2012
403
15
18
San Francisco, CA.


another update. Some tank art.

Bike is still thirsty with an 85 jet, needs around a 90. Just waiting on the part. Despite this it runs great, hit 35 mph today. Hate blind tuning so I also put on a temp gauge, which confirmed my suspicion: lean. The bike will easily go over 400 degs going up the hills we have around here (big san francisco hills) So need to richen it out.

I really want to get mag wheels for this bike.

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trying to be a little more understated than these Miami folks' bike, but also think these wheels are rad! When they come back in stock on http://www.ebay.com/usr/mzpartsmiamimzpartsmiami?_trksid=p2047675.l2559 I will try to get some.

This bike has almost no vibration, a testament to the sweetness of the OG 48cc !
 

ZipTie

Active Member
Jan 8, 2016
750
82
28
Mpls Mn
Those wheels would look nice in black on your bike. They seem to be out of all the GT2A frames too at the moment.
 

Moto

Member
Jan 7, 2012
403
15
18
San Francisco, CA.
Got a bigger expansion chamber
http://www.treatland.tv/puch-estoril-performance-pipe-p/puch-estoril-w-internal-baffle.htm

It's pretty hacked up but works well. Definitely fast. Bike now solidly pulling 35 mph, goal is 40 but that's a hard point to actually achieve. No long flats where I live and this little engine is turning pretty fast at those speeds.

Anyway... Bike wants more carb! I want more carb! I've got a 21mm dellorto, but it's a little too big. Really think the sweet spot would be around 18mm. But the phbg carb is huge and fun so I will play around with it. Definitely need a better intake, when I used this carb in the past I epoxied stuff together. Fred (head) dude makes some beautiful intakes but $$$! Just need to find a muffler shop or something to weld me up a simple intake.

Super "stock" build ;p
 

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Moto

Member
Jan 7, 2012
403
15
18
San Francisco, CA.
Got a fake dellorto carb because the stock one was running super lean to matter how I jetted it. Also put on a lil under pipe. Running rich now but with tuning will be better.
 

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Moto

Member
Jan 7, 2012
403
15
18
San Francisco, CA.


back to being the super stock build! I was inspired by the exhausts in early bicycle engine kits, and managed to find some in the same style being sold on ebay. Shipped from china. Chrome is super nice and this exhaust is actually really powerful. Non restrictive baffle and a strong power band from low rpm to close to redline. Really bumped low end power. And i like the way it looks.

Bike running great. Not sure how many miles but about 10 tanks of gas. I dont get nearly the gas milage of folks who live out where they can ride without stopping or going up a hill for more than a block, though. :p
 
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