The "100cc" conspiracy Read before you buy.

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Wevil Kenevil

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Mar 4, 2022
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I've been in the bike building game for about 5 years and with the help of such people as fast Eddie and Tom Rubicon and sidewinder Jerry and wrench and Tony norm from Venice bikes and all of my other mentors on here who I owe a debt of gratitude, I have learned enough to feel confident in making these statements concerning these motors.

If you don't want to read all of my blah blah blah don't buy the motor in short.

Following reasons are why I would not buy one.

MOST OF These are the regular China doll "80cc" motors that they build with just a @2mm bigger piston and usually a honed out cylinder which makes the sidewalls thinner. ONE OF THE ONES THAT I GOT WAS SO UNEVENLY HONED OUT THAT THE BOTTOM SKIRTING HAD BEEN GROUND THROUGH.(see photos for example. If you look closely you can see the difference in width of the sidewalls of the cylinder.)

ALSO there is no compensating for all of the extra stress and strain that the bigger piston will put on the motor and it's components.

These motors were "designed" to run at a certain pace and tampering with this only causes the motor to run outside of its normal spec.

Ld100/yd100 cylinders and motor.

Unless you are going to be running time trial laps where precision is key you will not notice an upgrade of much.

This comes after me port matching using a G4 ld100 cylinder with a CNC high compression head on a yd100 bottom end that I replace the bearings and the seals. (See photos)

Yes there is an increase in performance and power but it is not enough to compensate for having to order special sized parts for the larger Ld 100 cylinder. Gaskets, cylinders ,heads, piston, piston rings, wrist pins, wrist pin needle bearings, carb jets...

Much less an exhaust pipe that is wide enough to match the cylinder. The side walls on the exhaust port on the cylinder are 3.2 mm wide in some places making it impossible to get a good seal without using metal putty to build up the area surrounding the exhaust port.

I have had stock 80cc China girl engines that ran just as good as without the vibration.

Now the single cylinder yd motor does have the exhaust port that is matched to most standard pipes diameters but the one piece head causes it to overheat and is just a pain in the ass and I would avoid it though it is note worthy that it is consistent in it's integrity and good for people that do not have any mechanical inclination.

But overall I would avoid the hundred cc rabbit hole as having parts that are interchangeable I think is the key to being able to tune your bike in to run its finest.

I hope this is helpful to someone and if there's any questions please feel free to ask and if you have anything to add please feel free to do that also.

Peace 4 2024
 

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Wevil Kenevil

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Side note it's also a gas hog so it burns gas faster.

I really don't think that it's worth the trade off for the amount of extra power that you lose in gas mileage.

And on the positive side of having one of these is it looks cooler because it's 1/3 bigger and it's louder and sounds better but that's the only positive things I can note. (See photo 4)
 
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Wevil Kenevil

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Mar 4, 2022
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To update this topic I changed from an f2 thruster pipe to a niome flex pipe and rejetted it two sizes (74) and and also a Hp coil and stand alone cdi and it runs smoother and better mid and top end but still is yet to prove itself.
 
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Wevil Kenevil

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The motor is strong and Def gives me alot more top end. With a 32 tooth on a 26 with my 180 lb butt it wouldn't be a surprise if tuned in a a little more it would go 60 :confused: on a good day.

The longer pipe definitely helped it smooth out a lot. But still all of the gaskets and other things that are required to buy just don't make it worth it in my eyes.
 
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