1) Engine problems.. If your quad wont run..post in here.

HOW TO carb adjustment on any Chinese atv. Kazuma, Yamoto, Redcat, Baja, Sunl, etc...

Old Sep 28, 2010 | 10:32 PM
  #241  
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Maybe, but again that would be the timing marks.
These engines are very simple designs. Not much can go wrong unless something is out of place. Otherwise they are just big air pumps that suck gas in, go boom, and blow exhaust out.

You might need to pull the motor off the quad to check it out.
 
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Old Sep 28, 2010 | 11:04 PM
  #242  
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3rd times a charm? Well I'm confident that the valve clearance is OK now, but now I am questioning the timing. On the compression stroke I made sure that I could see the t in the sight hole. I looked over at the cam gear and the dot was facing the front of the head (where I thought there was a indicator notch). However, there is another little triangle in the cast that is 90 degrees counterclockwise from the one I was originally observing. Since the dot lined up with the notch on the front of the head, I did not question it. My question is, what if it is the other notch. From reading the other posts, I do not understand how to actually change the timing. Do I need to remove the cam gear and chain?
 
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Old Sep 29, 2010 | 05:16 PM
  #243  
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Solved my issue! Turns out the gasket I installed was worse than the original! I installed a new one and the noise is gone. It's still having a tough time starting, but I think I just need to adjust the idle settings...
 
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Old Sep 29, 2010 | 06:09 PM
  #244  
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Originally Posted by atv4rjw
Solved my issue! Turns out the gasket I installed was worse than the original! I installed a new one and the noise is gone. It's still having a tough time starting, but I think I just need to adjust the idle settings...
Awesome! I would not of suspected the head gasket, but did think that there might of been an air leak and is why I suggested checking the intake seals.

Cold starts are tough, play with choke.
A warmed up engine with an adjusted carb should start right up. I make the adjustments on the carb after the motor warms up. I start with the idle screw(with spring). Run it a while and then check spark plug to se if it is too lean and then make additional adjustments.
 
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Old Sep 30, 2010 | 07:23 AM
  #245  
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thanks for all the advice. I got it running now, but still need to play with the idle as it's a bit fast (if I let go of the brake it goes!) I'll check the plug condition after I run it a little longer tonight.
 
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Old Sep 30, 2010 | 09:11 AM
  #246  
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Default 50cc quad keeps cutting out

Originally Posted by 2manytoys
Alot of people have a hard time starting and running the Chinese atv's when new and also when cold. Most of these come with a gelpac in the carb floatbowl for shipping so it does not ruin the float. It is supposed to dissolve when fuel mixes with it. Many make the mistake of driving the atv once started. This is a mistake. You must let it idle for at least 30min for the gel to dissolve. If you do not do this you will risk the chance of clogging the jets and the initial adjustments will not work and it will not run right untill all the gel is gone. Most of the time these will start with the movement of the choke then you can lightly feather the throttle to keep it running. If you can reach the idle screw you can turn it up till you dont have to feather the throttle. After about 30 min you can make the final adjustments. CHANGE THE OIL BEFORE YOU RIDE!!! These come with a cheap shipping oil and must be changed or engine damage will occure. It is best to use an oil that is classified JASO MA certified made for 4 stroke or motorcycle engines which are made for wet clutch applications. These have no friction modifiers that are bad for clutches. You can even use diesel oil like Rotella-T 15w40. These oils can be found at your local WalMart or autoparts store. Synthetics are fine as long as it has the same classifications listed above.

The idle screw is the screw on the carb with a SPRING around it. The air/fuel screw is the flathead screw usually before the idle screw closest to the air filter. Some newer carbs have the a/f screw on the bottom of the float bowl. Here are some basic adjustments to get it started and to tune it once broke in.

The mixture screw had been set-up at the factory before shipment and should not have to be reset. Only a small adjustment may be needed due to climate and elevation. If necessary, refer to the adjustment as below:

1. Make sure the air cleaner is clean.
2. make sure the choke lever is OFF while running.
3. Warm the engine up for 3-5 minutes.
4. Turn the mixture screw clockwise until fully closed,
then turn the mixture screw 2 full turns out.
5. Adjust the idling screw until the engine idles EASILY.
6. Turn the mixture screw slightly clockwise and
counterclockwise until the highest engine REVs is obtained.
7. Adjust the idling screw again until the engine idles
EASILY.
8. Repeat step 6 & 7 till you get the best
performance...
*ENGINE IDLES EASILY means:
The engine idling screw must be set correctly to get a
slowest engine idle(1500 rpm - 1600 rpm), but does not
cut out if you press the accelerator quickly.


Cold weather starting will need an additional adjustment to help aid the starting process.

Most of the manual choke carbs have an adjustable needle inside the carb. Lowering the clip (raising the needle) you will be able to open the throttle and get more fuel into the intake quicker. This helps in the cold weather because the colder the weather the leaner the mixture is. You want richer in the colder weather.

1- Unscrew and pull the top of the carb off with the cable and there will be a slide with the needle in the center. (Notice the way the carb slide came out) In step #6 it must go back in the same way it came out.
2- Disconnect the cable through a small slot in the side of the slide.
3- Now you can take the needle out from the slide.
4- The needle will have a very small e clip in a slot on the needle. The needle will have 5 slots. Lowering the clip is richer the and raising the clip will lean it out.
5- Put the clip on the lowest setting for cold weather. DO NOT DROP THE CLIP! They are very small and hard to find.
6- Reverse the process with installing the needle back into the slide, installing the cable, slide the slide back into the carb and screw the cap tight. Remember in step #1 how the slide came out. It MUST go back in the same way.
7- Now make any adjustments as stated above in the carb tuning.

WARNING!!!WARNING!!WARNING!!!
Remember in step #1 and step #6 I said the slide must go back in the same way it came out? The slide will go in 2 ways. ONLY 1 way is the right way. If the slide is not put in the same way, upon start the quad will take off at full throttle. Make sure when you go to start the quad you have a hand on the kill tether or switch this way if it does take off you can dissable it. If this happens the slide was put back in 180 degrees out. This is very important for the safety of you and anyone standing in front of or around the quad.


These steps will work on 99% of these atv's. They are very hard to get running and people get upset when they turn the key and it does not run. Dont forget these are not set up at a dealer like the name brands so the most basic adjustments are done from the factory. These are built in china and the temps are hot so thats how the adjustments are done. As we all know in America the temps vary and these are not set at all for cold temps.

In some cases you will have tuned the quad and it runs very well but one day it will not idle or has poor performance. Most times it is because the carb has sucked in some debris from the tank. You will have to dissasemble the carb and clean out the pilot and main jet. Make sure you have a good inline fuel filter. This will help prevent this failure.

Hopefully this helps everyone with these concerns. These really do run good once tuned properly and with proper maintenance they will last a long time. And if you have any questions PM me and I will try to help as best as I can. Also once the temps start to get hot you may need to raise the clip for the warmer temps.

Good Luck!
2many
Hey man can you help me out sons 50cc quad keeps cutting out check out kelstar to see the full version of the story
apprecate your help if you can you seem to know your stuff about these china quads
 
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Old Sep 30, 2010 | 09:13 AM
  #247  
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see if you can help me out with my china quad i have a problem will you check out kelstar for the full story apprecaite your help
 
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Old Nov 11, 2010 | 09:36 AM
  #248  
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hey there I have a zongshen 250 sports quad.
It was having trouble staying running (would only idle) bog out when trying throttle.
followed your steps on here to clean carb (was amazed at the pile of dirt that came out of it)
put it all back together and re-installed into quad.
put the sleve with the throttle needle back in the top only to find out that I had it 180deg out (throttle lever was really sloppy)
took it out turned it and re-installed
now i have to have choke all the way closed in order to run????
let go of choke and engine dies......do I need to lower the e-clip on the throttle needle?(getting a little cool here in B.C. Canada)

you can tell it wants to start and run but as soon as you give it gas it sounds like it is sucking alot of air at the air filter and dies
 
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Old Nov 11, 2010 | 11:32 AM
  #249  
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side note: I have been told by two different people that I need to take it apart again and use a needle to clean out the jets as it sounds like my jets are plugged....will give that a try today and see what happens
 
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Old Nov 11, 2010 | 06:50 PM
  #250  
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SUCCESS!!!!!


Took my carb off again and went at the jets with a needle then blew everything out with air and re-installed carb. after messing with the settings for 2 damn hrs I finally got it to idle great and no more sucking air and bogging out and dieing.....goes better now than when i first got it a couple of months ago.
 
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