We won a SunL 70cc five years ago at a drawing at the local bar. Since our son was just one yet, we drained the gas let it sit in my fatherinlaw's shop. Last summer we took it out and had a bit of trouble with the throttle, but nothing too serious.

This spring when we took it out the carb was full of crap, cleaned it, son drove for a couple minutes and it was full of crap again. Changed the spark plug and air filter seems okay. Any suggestions why it keeps gunking up?

 

Blackbird, Sounds like you did things correct to store the bike. A lot of the Chinese ATV are shipped with a gel in the carb bowl to protect the float assembly. You are suppose to run the bike for 30 minutes or so to dissolve the gel. If you didn't do that when you stored it, that might be where the crap is coming from. Check the fuel filter and see what it looks like and then go from there. When you work on these babies always take your time and don't be in a hurry. I will be suprised if you don't already have the thing running. Good Luck, Drummer Boy

 

I have been playing around with different jets for my tao tao 110d quads. My problem is very poor acceleration to the point of bogging during take off on both of the quads. I have changed the main jet to an 80(from a 75) and the pilot jet to a 32(no number on stock pilot jet) on one of the quads. On the second quad all I have changed is 32 pilot jet. The bogging has ended on both of them but the spark plug check shows it is running lean as heck. I am not sure where to go from here. I read somewhere to adjust the air screw get the quad going at about 1800 rpms and turn then screw clockwise until the rpms drop. Then come back out until it revs to the highest point. But like I said they are still so lean I am afraid of hurting the engine. My kids drag race so most of our passes are wide open. The mid to top end is great on both but bottom end sucks. Please help.

Josh

 

Josh, I will tell you what I continually tell myself. KISS [keep it simple stupid] These things are made to run and are engineered by people a lot smarter than us. Before I would be changing jets, I would be disassembling the carberator and dipping it into a gallon can of carberator/parts cleaner, to make sure you are starting with a clean carb. I have done this numerous times and have always had good results with out having to make radical changes to anything. Never be in a hurry working on these things either. Good luck and KISS, Drummer Boy.

 

Thanks for the reply drummer boy. I have cleaned it and even had the dealer replace the carb. I bought these in brand new in march and both a bikes bogged from the start. Trust me I tried to keep it simple. Good news is my oldest son won last night on one of them. So I guess the jetting helped. But I know the way I have it setup now is hard on the engine.

 

Hey there, quad newbie here. just got a 110cc quad for my kids and trying to get it going. read many of the threads which was helpful. replaced the oil and began idle and fuel mix adjustments and got the engine to sound pretty smooth. took it our for a spin in the yard to see how it rides. when I got back to make some final adjustments I noticed the head gasket was leaking. Bought a new gasket, installed and no leaks! problem is now I'm getting a banging sound (backfiring?) as I am starting the atv and especially when I push the throttle. I see a bit of smoke come out of the carb when the throttle is pushed but can't pinpoint the location. I can't eliminate this sound and can no longer keep the engine from stalling. Any help would be great! sorry for the long post...

 

if you removed the head, you may of affected the timing of the valves.
It is possible that your timing chain is stretched or that your tensioner roller is bad. I would disassemble and reset the timing. You may need a manual for this. check the valve clearance.
.004 intake and .006 exhaust.

best timing advice.....

http://forums.atvconnection.com/kids...ve-timing.html

 

Thanks for the reply. I followed the instructions in the link you posted and the chain tension and timing seems OK (as far as I can tell). As far as the tensioner roller goes, how can I tell it's bad?

 

It will have excessive play with the chain.

If your timing marks line up on the crank and cam gear and the valve clearances are correct, then you should not be backfiring. Something is still a miss. Especially if you did not have this problem before the head gasket.

Check your intake seals to the head also.

Mods- this thread should be split to another topic as the head question/comments do not pertain to the carb adjustments.

 

OK thanks. It's definitely not the tensioner roller then. The chain seems fine. I just spent a couple of hours double checking the timing and valves. The valve clearance seems OK, but it's hard to tell as there isn't much room to maneuver while I'm under there. I tried starting it up again and it still sounds like a firecracker going off! Ignition problems maybe?