100 cc 2 strokes... ARE they?

Nashville Kat

Nashville Kat

Well-Known Member
This might be old hat and sorry if it is, I don't get here much anymore at 69 and barely still into tame electric bikes:; I just became aware of the 100cc China Girl and my first question is Are They? As the 80 was really just 66, is the 100cc claim correct? And then what's the quick details? Larger piston surface, longer stroke, what?

And next then? How are they/ Powerful? Reliable? Noisy? Vibrations? etc. What? What What?

Thanks in advance
 

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There 79cc more power than a 66/80 there bigger case with thick seals on both sides... 50mm bolt spacing there's a 2 piece head LD version... There's a 110 that's 85cc that's a lemon except for the case reed and I'm looking at different jugs for the 110... Utube has some good info on LA hover and Johnny's motorized bikes
 
Well I'm interested in them theoretically, but it's sooo much harder to wrench as I get older. This "80cc" pictured has the original motor I bought from Bikeberry in '09, and still with 6mm jug rods . I shook it out the other day- I hadn't ridden it for at least 2 years. It ran poorly until I put fresh gas in- I shoulda emptied the tank, but it's going like new now. All that's not stock is the billet intake.

I'm toying with the idea of trying to ride it from Ormond Beach to Jacksonville- a short jaunt of about 90 miles, to pick up a jalopy I have there, but I'm not sure the motor, or me might make it.

s-l500.jpg

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Kat good to see you back on the forum, I have a engine that I added a 49mm bore iron sleeve top end to, it a standard two piece head and cylinder design. It's around 75cc. Most of the 50mm bore engines have a one piece head and cylinder, I've heard that they are more for low end torque.
 
From my experience you will need to take extra fuel, with the stock tank around 70 miles is my limit. I've thought about getting a one gallon tank but haven't got around to it, I carry a water bottle with me with about 20oz of fuel, just enough to get me to a fuel source.
 
Greg58 said:
Kat good to see you back on the forum, I have a engine that I added a 49mm bore iron sleeve top end to, it a standard two piece head and cylinder design. It's around 75cc. Most of the 50mm bore engines have a one piece head and cylinder, I've heard that they are more for low end torque.
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Seems like a longer stroke, so as most of the limit to these engines is the top rpm, I guessed that maybe was the case. I'm wondering how heavy they are? I've still got two gas bike builds, and ended up riding a 50cc more than the 80 anyway- it's not as fast or powerful, so maybe not the bike for 90 miles. As to gas- I'd plan to carry an extra liter in a small aluminum bottle, but there are many stations all along the way.
50cc Huffy.jpg
 
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As I’ve got older my behind runs out before the fuel, I have the largest seat I could find on the bike I ride most.
 
The engines available now days are usually 69cc, they are 47mm bore with a 40mm stroke. Its rare to find the 38mm stroke engine anymore. I've seen several different bore sizes listed on eBay, 48,49,50 and as Mossy said the newest is 52mm, I can only speak for the 49mm. I just got mine out for a short ride, it feel good to hit the road in short sleeves.
 
The big bore cylinder kits are not plug and play, you'll need to degree the port timing of a known good performing engine and port the cylinder using those specs as a start, the sleeve openings are a rough cut that I wouldn't dare run as it comes, I have a second cylinder and piston for a future project and the ports on it are the same way. I had to hone the bore for proper piston to bore fit also.
 
Greg58 said:
The big bore cylinder kits are not plug and play, you'll need to degree the port timing of a known good performing engine and port the cylinder using those specs as a start, the sleeve openings are a rough cut that I wouldn't dare run as it comes, I have a second cylinder and piston for a future project and the ports on it are the same way. I had to hone the bore for proper piston to bore fit also.
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I'm taking I suppose about whole kits and whole engines I saw listed on ebay.

www.ebay.com

CDHPOWER 2 Stroke YD100 Engine Silver Color Engine -Gas Motorized Bicycle Motor | eBay

CDHPOWER 2 Stroke YD100 Gas Engine ONLY, NO manual, YD100-50mm 79CC/80CC Engine;. CDHPOWER Support Team. 2 Stroke Gas Bicycle Motor Only YD100-79CC/80CC Engine Kit; Bore and Stroke: 50mm x 40mm. Bore and Stroke: 50mm x 40mm; Better adjusting clutch a little before riding;.
www.ebay.com

This is formidable appearing at least https://www.ebay.com/itm/125760260471?_trkparms=amclksrc=ITM&aid=1110006&algo=HOMESPLICE.SIM&ao=1&asc=247415&meid=eac84ad9a61d4562952ad6d928a15c1d&pid=101195&rk=3&rkt=12&sd=195507138543&itm=125760260471&pmt=1&noa=0&pg=2047675&algv=SimplAMLv11WebTrimmedV3MskuWithLambda85KnnRecallV4V5V6ItemNrtInQueryAndCassiniVisualRankerAndBertRecall&_trksid=p2047675.c101195.m1851&amdata=cksum:125760260471eac84ad9a61d4562952ad6d928a15c1d|enc:AQAHAAABQBEC%2B8HimpTF6XPanG8lCeF3G6jifrewDlLoKJMPz0RnJH8s%2BUBlIo2cSQSdgSGvSW%2BiypWzATNrgsi2agxJDshTUcICtN84koFIxBjyT3J0Yv2cJO9SxJpCd6oLiUW1WFpLF3ZtVHQyxywf3rDdRkIEejqMGFMZiBRceA3tdi47tRpr7TMlgJIQoqRwU7sRNM%2BJ7K%2BCCCQRf6Z7Mvx9eXAo%2BvSp4U9iG3qVji5R05pbCYmTBylN8Dw1Jmynj%2BAeY0sBPMG01ohpkWBmEWwleNc4xfOkw5bIjyGfNjs60xxCB5aca4JplGEgdRS5FkS7c10IzWDwnGe43C2Xzq6Fx2DwoF7F1Vf0iDazvo0BbeY61M7oamBI34xbf%2FFi8zGP98SXxxkeVgHTQmqcJYmU7kkiMuZW4aZLHxzbpkZjkANO|ampid:PL_CLK|clp:2047675

I'd hope that by this level they'd have 40mm intakes

Doing a quick scan of specs where they care to give them, it now appears that I assumed wrong about the stroke- most are saying 38-40 across both the "80cc" and the "100" So I guess the piston bore is the big change, and they play around with different big heads, or heads with fins turned horizontal t lend an appearance of longer stroke.
 
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The YD is a one piece cylinder and head and the LD is the 2 piece version
 

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