I tried blowing into the top of the fuel tank and it helped alittle. If I increase the air pressure with an air pump will it increase the effect? Also after I started it up today I looked into the top of the carb while the atv was off and there was fuel in the carb where the needle meets the fuel jet, is that supposed to be there?

 

I don't know if it's supposed to be, but it often is.

 

Thereshould be very little fuel if any that is just sitting in the carb venturi. The last time I had that problem it proved to be the float level being set too low. The range given in my manuel is 12.5 to 13.5 mm. Mine is happiest at 13. If your level is too low it also can fill the cylinder with gas and that can cause starting issues.

 

would a low float cause a rough idle or problems at high rpms?

 

We set the floats wrong on a raptor and I took it out for a test ride. I was doing donuts while my friend was jumping up n down waving his arms and yelling. I didn't see him at first, but then I rode over to see what the problem was. He said look at the pipes! They were cherry red like a neon sign. The lesson I learned from that is you can set the floats wrong and it will run great.

The float height doesn't seem to matter that much until you run it hard enough, for long enough, to suck the bowl dry. Or if you ride up or down steep enough hills and the gas flows into the intake.

Another thing to bear in mind about the float height is the floats lose their ability to float over time as they absorb the gas. No polymer is totally resistant to gasoline. The brass floats are better, until they get a pin-hole.

The first things I would do to any 300 king are: 1) Check the regulator. Mine had a crack in it. My friend's had a crack in it. Bunch of people online had bad regulators... If yours doesn't, I would consider that a miracle. 2) Check the intake lash. 3) If it's still running bad, swap spark plugs and see if it helps. One time I was about to tear a carb apart when I decided to change plugs first. Just because a plug is new or looks good, doesn't mean it is good.

Regulator:



Petcock:



Fuel pump:

 

My atv is a 01 quadrunner so none of my parts look like that, my fuel pump is plastic and doesnt come apart. I havnt taken apart the petcock yet, why do u plug the one line coming out of the petcock? Also what is the intake lash?

 

I forgot exactly, but here are some threads about it. Vacuum operated fuel tank valve (Petcock) - Suzuki ATV Forum

97 King Quad Petcock vacuum line leaking gas? - Suzuki ATV Forum

2000 King Quad 300 4x4 -- Fuel Petcock leaking - Suzuki ATV Forum

I think basically the diaphragm breaks and sucks gas directly into the intake, bypassing the carb. The fix is to plug the vacuum line and use the petcock like it wasn't vacuum operated.

 

i tried to adjust the intake lash but I couldnt find the TDC or whatever its called. So I instead tried to run it with the headlights on at high rpms but it still would bog down when the rpms got medium to high, what elso could cause this and hot can I tell when the piston is at TDC?

 

There are lots of things it could be, I was just pointing out a common problem.

To find TDC (top dead center), you take the intake inspection cap off and pull the spark plug out. Then pull the rope until you see the intake valve rocker go down and back up. Then stick a screwdriver in the spark plug hole and use it to touch the piston. Continue to pull the rope while feeling the piston rise. Stop when it gets to the top. You may have to go around a couple times to stop on the exact top. Now you set the valve lash on both valves. .001-.003 on the intake and .003-.005 on the exhaust. Try not to scratch anything with the screwdriver. A chop stick or piece of wood would be better, but screwdrivers are handy.

 

There is a 17 mm plug that comes out of the left hand crankcase. Take the recoil starter off and then look straight on at the starter cup. It is under the exhaust pipe. Then use a little mirror (like one from a dentist) to find and line up the line that has a T next to it with an arrow that is located closer to the piston. Sorry if that is confusing, i can take some pictures if you need. Anyway, once you find TDC i would make a small timing mark on the starter cup that will line up with one on the case. That's what i did to mine. Makes it so you can be in and out to adjust in under half an hr.
I set my intake lash to .04mm