I've got a question. I live in California, own a couple of 70cc chinese quads and according to the plug color, they are still running a bit too lean. Everything I have read states that most of these quads come tuned too lean in order to pass emissions.

Can I richen it up by using the needle process outlined here? Would I get any more power out of them if they are indeed running too lean? They both currently run and idle just fine, but I know running too lean isn't good for the long term. Also they appear to be doing well with the stock plugs but plenty of folks in this forum have mentioned tossing them and getting a "real" plug. What is the merit to such comments? I've had really good luck with these quads so far but wouldn't mind turning a good buy into a downright extraordinary buy.

Nick

 

They do run these a little on the lean side for emissions but not so lean to ruin the motor. You can richen certain circuits of the carb but once at wide open throttle the needle does nothing. The needle will affect idle to about 3/4 throttle. You can move the clip down to richen it up a little and most riding is done at about 1/2 throttle or lower. You will get better performance to a point by running slightly on the lean side but I dont think you will really notice it on these quads much. Most of my carb tuning tips is for new quads that have not been tuned yet or problem starting quads expecially in cold weather. If your quads are running good then dont fix it if its not broke. I do however suggest puting better air filters on them like K&N uni filters. The OEM filters are junk. By replacing the filters these little motors will run forever.

I have had good luck with teh stock plugs adn have owned over a dozen of these quads. Not one have I had to replace the plug. Will it run better with a name brand plug? Maybe! Or is it just a precaution knowing you have a good plug in the quad. If it starts to run bad or have hard times starting then the plug would be the first thing to look at. Then carb tuning.

 

I too have had good luck with the stock plugs in my Chinese quads but I changed them to NGKs just for the peace of mind. I have gotten in the habit of upgrading certain things on my Chinese bikes that I felt I wouldn't trust for the long haul. Talked to John at Raceway the other day and he is working on stocking American made bearings from now on as well. I might change all of my bearings out just for the peace of mind on that too.

 

Where do you guys get jet kits for these? I think my daughters quad runs alittle lean, Id like to play alittle with the jetting to richen it up. It spits a pops some at full throttle, it just started doing this when I replaced the stock air filter with a UNI. It seems to have better initial throttle response now, but at WOT throttle it pops just a bit.

 

I got my jets from here

JETS R US

 

so does anybody have any manuals on these? I am not sure if it is needed but if I am going to try to take the carb out and adjust this needle, I would like something to go by since this is my first go at it. If anybody does, maybe I could get a page or two emailed to me?

 

I have a manual for a Kymco Mongoose 250. PM me with your email and I can send the pages this evening.

 

Would that really help me on my Redcat MPX90? How do I send you a PM?

 

Doubt it's the same carb. Wasn't sure what you had.


If you want to send a PM to someone, just click on the picture of the lock in their reply.

 

ragnoinsc,

You dont have to take the carb off the quad to adjust the clip. Its just a matter of unscrewing the carb cap where the throttle cable goes into the carb. Pull out the carb slide that is attached to the throttle cable. You will then see the needle in the center of the slide. You now have to squeeze the spring up twards the cap and slide the cable out from the slide. Once slide is apart from the cable you then just push on the tip of the needle. It will slide up along witht the retainer that holds the needle ito the slide. Make sure you pay attension on how everything comes apart and how everything is positioned. Once you have the needle out then look at the e clip on the needle. There are 5-6 slots on the needle. The clip is usually on the middle slot from factory. You want to move the clip down about 2 notches for cold weather. Just put the open part of the clip on a hard surface and lightly press down on teh needle. The clip will come off. Set the clip on the lower notch and press firmly for it to clip back in. Then you will have to put it together opposite it came apart.

BE VERY CAREFUL on how the carb slide goes back into the carb. There is 2 ways it will go back in. Only one way is the right way. The other way the quad will tkae off at full throttle. Just remember how the slide came out and you will be fine. This is not hard at all. It usually takes me about 2 min to do it. It may take you about 10 the first time but once you have done it, it will be easy after that.