Minarelli Cylinder Kit.

GoldenMotor.com

cannonball2

Well-Known Member
Oct 28, 2010
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Colonial Coast USA.
Does look real similar. Its only 41mm. I would love to have either a cast iron cylinder or one with a cast liner. Bet this one has a liner. Wit a 40mm stroke it makes 50ccs I could live with that if it ran forever bore wise.
 

mapbike

Well-Known Member
Mar 14, 2010
5,502
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Central Area of Texas
seems to me someone with the skill and equipment could make a sleeve that could be used to convert a 66cc into a 49/50cc that would have a much longer bore life, the expense of doing it might make the engine to pricey.

Someone could perfect it and just sell a sleeved jug with the correct piston as a small bore longevity upgrade for the 66cc engine, since there are three configurations of the 66cc engine I'd say they would have to decide which one or two to set the deck heights for.

another important thing would be to stress that all bearing were replaced with high quLity ones if the engine was older or one that didnt come with high grade bearings.

all of this would make for a higher end china girl but might make a long life engine for those that use it for primary transportation.

do know how big the market would be but it would make a nice little engine I think.
 

cannonball2

Well-Known Member
Oct 28, 2010
3,682
221
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Colonial Coast USA.
Those were exactly my thoughts. If I had the extra$$ right now Id buy the Peugeot cylinder on a gamble. Im betting theres a basic bolt on out there some where, since copying is such a big thing. Could be this basic design was licensed to many manufactures at one time hence the similarities. Kind of like the DKW engine that showed up on so many small motorcycles.
 

mapbike

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Mar 14, 2010
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Central Area of Texas
I'm still waiting for someone to build an entire upgraded engine from the ground up with a nic machined case and jug, I'm sure it way more trouble and more costly than it would be worth messing with but would be nice.

I've seen some projects on youtube but thats about it.

personally I wouldnt spend sveral hundred on a china girl engine since the fact that they are so cheap is why I like messing with them, but someone out there might do it since some will spend $600+ on one that has just had a few upgrades to it.
 

cannonball2

Well-Known Member
Oct 28, 2010
3,682
221
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Colonial Coast USA.
Heres another likely looking candidate. The piston looks very similar as does the mounting base. If something like this could be made to work I think a reliable engine could be built. The GC cases seem ok especially if Helicoiled. The newer cranks seem ok too especially if trued and balanced. With high quality bearings added to the clutch and crank might become a pretty good little engine. The cost wouldn't be too bad either if off the shelf components like this could be used/modded to work. http://www.ebay.com/itm/MORINI-MOPE...her_Vehicle_Parts&hash=item27f6cf575a&vxp=mtr
 

mapbike

Well-Known Member
Mar 14, 2010
5,502
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Central Area of Texas
I cant remember the memebers username now, but a few years ago he used one of hese jugs to build an engine up, best I remember he had to machine a spacer to go between jug and case and Im not sure what else he did now but I think he was one of the first to balance the crank and build a 60mph china girl engine.

I still remember his avatar as being a dogs face but I cant remember the username.

For a while he would balance cranks for members for $100

I know someone else here remebers him so maybe they'll chime in and refresh my memory.

he stopped building the fast bikes and doing work for people because he was worried about the liability issues that might ome about if someone got hurt or killed using something he modified.

According to Fred Chelminski the "half breed" engines have a very well balanced and tdue crank that makes them run very nice and smooth, I just bought one of these engine two days ago and Im gonna build it up and see how it runs compared to the dax engines I have and a couple old BGF beaters I still run.

Fred claims that the half breed 38mm stroke pk-80 type engines have better primary crankcase compression along with the best overall crank of any of them as far as trueness and balance is concerned.

Im curious to see how this engine will perform and I may have it running this weekend if I have time.
 

Davezilla

New Member
Mar 15, 2014
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Yes, that was Foureasy, he made his with an Athena giordoni jug with a 45mm bore and built his own pipe welding every tiny bend into place.... the finished product made just over 8 hp and pushed his 24" bike over 45mph with awesome acceleration.
Then thrre was another guy on youtube that used a cast iron Minarelli jug connected to the case with a 1/2" thick steel plate that looked like he just cut out with a torch and a longer rod but i dont remember which rod he used, but his was putting out 14hp and spun at around 13k rpm, the bike was hitting 60 mph in short blasts on the dirt rooster tailing like a kx80 in low gear. I got a pm from Mrfubbs a while back with a link to the jug this guy used and a close up pic of the engine. I truly never thought a stock ChinaDoll clutch could hold that kind of power.... I'll have to find the youtube link and post his too... this one ya gotta see to believe ....
 

Davezilla

New Member
Mar 15, 2014
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San Antonio Texas
I'll post it in the morning when i get to work, i got most the info on that one but im on the kindle right now and it takes me forever to find stuff and type on this thing, but i can send you the link and the close up pics
 

mapbike

Well-Known Member
Mar 14, 2010
5,502
109
63
Central Area of Texas
that'll be good.

I know what you mean, when Im at work I use my Galaxy smart phone to do my reading and posting here, when people see bad spelling you can bet Im on my phone, my thumbs any this touch screen dont get along to well.