Hello everyone,

I just joined the community. I wanted to thank all of the contributors ahead of time, it is always cool to see so many people willing to share their time and knowledge so freely.

I bought my son his first starter ATV for Christmas, since it's his first and I wanted him to learn on something economical. The wife and I ordered a Chinese TaoTao 125cc ATV that I picked up from superiorpowersports warehouse in California. I opted to pick it up because I had read so many shipping nightmares with packages showing up damaged. Anyways, I followed the instruction to assemble the ATV and got it put together, changed the shipping oil out for regular oil, put fuel in the tank and it literally fired right up and ran. I set the throttle limiter way back for the "break-in" period of 8 hours. I had my son ride it over a period of several weeks at low speeds, primarily on-road for an hour at a time. After the break-in period, I changed the oil out, checked the chain to make sure it was tight, inspected the spark plug and went ahead and opened up the throttle. We have a Polaris 700 and a small 110 Joyner go-kart so we made plans to go on our first "official" family ride off-road, however the trip was brought to a VERY quick halt when we discovered that my Son couldn't keep up going even just 10 mph. The ATV was completely bogging out, lagging or sputtering at WOT. Thinking it might be a fuel/air mixture issue, I begin searching for the adjustment screw and soon realized that all screws, with the exception of the idle screw had been intentionally cut off to prevent adjustment. Convinced it was a carb issue causing the lag, I ordered a new carb, that came with a new throttle cable and I also ordered a new spark plug online just in case. I installed both and had my sun jump on and go figure, same results. Since then I have followed threads on this site to adjust the top and bottom valve clearance and also test for vacuum leaks. I actually found a vacuum leak and replaced all the lince with better clamps until I got NO engine rev when spraying starting fluid around the hoses. I also made the small adjustment on the needle retaining clip on the new throttle cable as a few videos suggested, but nothin has produced any results. One interesting note is that it doesn't seem to bog down when I have it on blocks and put it in drive and give it throttle and it has NEVER bogged down when in neutral and giving it throttle. When pulling the plug there has been some blackening as of recent, but nothing major. It seems like it would be a fuel supply issue, but I am at a loss for ideas. I have unplugged the fuel line from the carb and let it flow into a container and it seems to have a good flow of fuel so I don't think it's the in-line filter that's causing and issue. I've also unscrewed the needle at the bottom of the bowl to let it drain and it seems to have a pretty steady flow of fuel. DISCLAIMER, I AM far from being a mechanic, but I do know the basics and have usually been able to fix my own ATVs, karts, etc. ANY HELP on this one would be very very appreciated! My boy keeps asking WHY SANTA would bring him an ATV that was broken....it's become somewhat of a joke that "apparently he didn't think he was all that NICE this past year." LOL!!!

 

Welcome to the forums.

I've moved this to its own thread to help get you some more direct answers.

Not an expert at all, but have you checked the clutch at all?

 

usually if their is a bogging issue it will not show up when their is no load on the machine when the wheels are up in the air... have you dissembled carb and checked float setting and such? I would almost bet the float is set wrong and its flooding or running out of fuel under load. Also double check your compression.. What carb did you put on a stock carb or did you upgrade to the mikuni? The mikuni is sold as a upgrade for these machines a much more reliable and user friendly carb

 

Hello Zrock,

Thank you very much for the reply. I replaced the stock carb with the following: Taotao Coolster Carburetor Upgrade w/ Throttle Cable https://www.whygostock.com/taotao-coolster-carburetor-upgrade-w-throttle-cable/
I ordered off the above listed site, whygotock.com and I also order a NGK spark plug from there and installed it. So just last night I had the new carb taken apart and made sure everything was clean on it, I even took the float off and sprayed cleaner through the inlet to make sure there wasn't any clogging and everything seemed to be clean. I haven't check the compression, I don't really have the tools to do so....would just placing my thumb over the plug hole and cranking the engine be sufficient? I will do that tomorrow first thing and report back...otherwise if I really need to I could always head to autozone or somewhere to pick up the tool. Should I look at getting the upgraded carb you recommended? What's the best site to look at those upgraded carbs? Thank you.

 

Did u check and make sure float level is correct? Have u verified the manual choke is working 100%. Putting your finger over the hole will tell you. It should blow your finger off easily. You should be able to rent the tool locally. I cant remember the part number for the carb but a quick internet search should bring it up...

 

Forgive me for my ignorance, but how do you check to make sure float level is correct? It moves easily and freely up and down. The manual choke seems ro be functioning normally. Thankyou

 

You will have to Google that one... I know how to do it but not how to ecplane it well...

 

Sorry for the delayed response, I had to go out of town on business. I was finally able to check the compression and it appears to have good compression. I also attempted to adjust the float on the carb and adjusted the fuel/air screw to 2 1/2 turns out from seated. However, I am still getting the same results with a load on it. I went ahead and ordered the mikuni carb, new k&n style air filter and a new fuel filter. I will install this week when they get here and report back on any changes. I'm really hoping that they just sold me a bad replacement carb. Thank you again for your help.

Dan

 

Hopefully that fixes things for you. Worst case when the problem does get resolved it will have a little more get up and go..

Just out of curiosity have you contacted the seller for warranty?