Well I have been working on my atv all day and still having issues. Somehow the carb is getting flooded no matter what I do. I adjusted the float level to where it is pretty much closed with the float at the lowest point. The atv will start and idle perfect for about a minute, then it starts stumbling and falling on its face and dies. I can then drain the carb bowl and it will fire right up again and idle fine....then in about a minute it will start to stumble. I cannot figure out why it is flooding??!

At ideas on how it is flooding even with the float adjusted really high?

 

Sounds like you need a carb kit that includes the needle and seat. If the needle or seat are worn,fuel can still by pass the float arm filling the bowl up even if the float level is set high.

 

Among other things I think you need to be a little more precise on measuring your float drop. Using a yard stick isn't close enough and being just a frog hair off can make a difference.

 

I already bought a carb kit and replaced the needle and needle seat. Same issue is happening.

I measured the float height with some digital calipers at .52". At this height the atv wouldn't even idle at all. After I increased the height to around .75" it began to idle for a bit but then it would stumble and die. That's when I could drain the carb bowl and start it again as I mentioned above.

 

Could the main diaphragm be causing the problem? It doesn't appear to have any holes or rips in it, but there might be something I'm not seeing.


Also, what is the stock setting for the float height? .51" from the bowl seat to the top of the float?

 

Still sounds like float related,either sticking or float level if you have a new carb kit and still leaking.Plus don't over look the over flow tube for any splits.Just fill the bowl close to the top and see if it leaks through the tube. Plenty of videos on You tube,plus here's a pdf link to a cheap manual that can show you specifics.Shop Service Manuals - A.T.V.

 

well after doing some more tweaking this evening, I am still having problems but it has gotten a little better. I put the original stock needle back in ( what notch should the clip be in?) and adjusted the float to be at .51" . I also regapped the spark plug (which was black and sooty)

The atv will start up and run good for about 30 seconds but then starts to idle pretty rough. It will get rough enough to almost die. If I slowly give it some throttle it will bog and almost die, then when I get above 1/4 throttle it runs smooth.

I noticed if I disconnect the intake hose from the carb, the idle would smooth out a bit.

 

I tried changing the pilot jet to a 40 and then a 37.5 from the stock 42.5. The atv would still run but very rough with the pilot screw all the way in. I tried the pilot screw from the seated position all the way out to 3.5 turns out. I unhooked the intake tube from the carb and it would smooth out a bit, then I would put it back on and the atv would then stumble and die. I'm at a loss on what to do?! Why would the pilot jet all of a sudden be causing this much of a problem or be that much off? It revs fine from 1/4 - WOT. Just the idle and 1/8 throttle is causing issues.

The other thing I noticed was the fuel shut off does not completely. Fuel still trickles out while in the off position. Could this be causing the issue?

Any help would be greatly appreciated!!

 

I cannot understand why it will idle ( still rough though) when I unhook the intake boot from the carb.... And it will stumble and die when I hook it back up?

When I open the box up or even take the filter out....it won't idle.

I installed a new spark plug and ran the atv around the block and pulled the plug and it was already solid black.

I thought maybe the diaphragm wasn't working, but with the intake boot off, I can see it raising and lower as I give it throttle and let off.

I'm about to give up on this thing. Anyone that can help I would greatly appreciate it.

 

I decided to try a chem-dip on the carb. Well I pulled the carb and stock pieces out of the dip after 24 hours and blew everything off. I made sure everything looked good and clean and started reassembling it all. I got it all back together and on the quad, started her up and she idled kind of high at first. It was a smooth idle, but it was too high for sure. After about 10-15 seconds the idle started to drop. Then it started getting rough again as the quad warmed up. After about a minute or so it got really rough and was struggling to stay running again. Same old thing.....

I pulled off the intake from the carb and it started idling high but it was still really rough and uneven.

This is getting frustrating.