Hello I have 2 little quads with 50 cc 2 stroke QINGQI scooter motors in them. Well after a year the kids are getting bored and I would like to speed them up some, where should I start? I moved the clip on the needle to the top position and it didn't seem to help, also I have no clue what size the main jet is. Would moving to a bigger jet speed it up? Should I look into a bigger carb? How can I tell if it's restricted electrically? The pipe doesn't appear to have any restrictions. The air cleaner assembly looks very restrictive. The carb has the word "might" cast into it, not sure of its size. These are not CVT bikes they are centrifigul clutch bikes and I was told these are much slower. Any help you 2 strokers can give me would be appreciated.

 

Check out www.miniquadperformanceparts.com. This guy carries some sweet parts. I know him personally, and you couldn't find nicer people. I watched two of his 90's with all the motor mods, run today at a barrel race, they smoked the all the other minis!

 

You dont want to move the clip to the top. There is no performance gain!! You have only leaned out your midrange and could burn up piston. I would call one of the mini quad performance shops or post a pic of your bikes and engines I would imagine they are very similar to other mini quads. There are more performance parts than you could imagine.

 

Fastest dad will going to a bigger jet help out the leaning problem, or does the jet needle need to be lowered? I'm all thumbs when it comes to carbs, but was told moving it up a coupld of notches would help it out.

I will have to get pics up soon, because I need to find jets for the carb, it looks like a little Mikuni, but has the word MIGHT cast into it.

Thanks

 

no sense messing with the jetting unless it needs rejetted. if you have run the quads a couple of years this way then the jetting is all right. usually the only reason to rejet is if you add a race pipe of low restrictive air filter such as a uni or k&n. leave the jetting alone or you could seize your motor or burn a hole in the piston.

Mark

 

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spjohn,

Changing the jetting on your carb(s) won't give it dramtic amounts of power. If your carbs were off (re: running rich to begin with), then leaning the mixture would give it a little more power. Actually, the power gain from a "proper" mixture isn't even noticed on trail or "around the house" riding conditions. But racers who are always running "on the edge" can tell a difference. As someone once stated, there's a fine line between a perfectly tuned to a blown up 2-stroke mini. If you can, get its spark plug to a Beer Bottle Brown and maintain this color. This is the "on the edge" color your minis always need.

We definately need pictures of your minis. By "seeing" what exact brand you have, the performance experts on this forum can give you RAW info on how to get more power out of these 50s. Tweaking the mixture on the current carbs isn't the "instant magic" you're looking for. If the carbs were set properly, then leaning out the mixture will blow a piston. The jets / mixture on these carbs are very sensitive to change. Change in weather and in altitude.

For your 50s (assuming they are "average" 2 stroke 50s), here's some high level ideas for major power gains:
- Replace its current 50cc cylinder / piston / head with a 70cc upgrade kit. This is the "power house" fundation that most do first.
- Replace its air filter "box" with an open air filter. Uni, K&N, Twin foam allow more air into the engine.
- Replace factory reeds with Performance Reeds. This allows more air flow in shorter time to get into the engine. Definate quicker throttle reponse from this mod.
- Depending upon your current carb size, you may have to upgrade the carbs. Many like the 20mm or 18mm on a 70cc cylinder. If your mini is using a 16mm or less, then an upgrade "may be required" for more air flow - that's expected of your 70cc upgrade kit.
- Install a Performance Pipe -> if one can be mounted in your specific brand of mini.
- Install Clutch kit with matching rollers -> assume its a CVT tranny.

There are other mods that can be done to an "average" 2 stroke 50cc. But these are the "most used" upgrades for folks who want more power out of their current 50cc minis. Also, if you upgrade their performance do remember to upgrade their suspension as well. No use having "a rocket" if the young rider can't control them across the bumps.

For upgrades, I've had great luck with Billy Holt at WRH Racing. URL: http://www.wrhracing.net/home

As stated above, the performance consultants need to know more details about your minis in order to make more specific recommendations.

Hope this helps....

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yeah it helps a bunch thanks for the tips