1996 king quad 300 4x4 idle issues

[willarid]

Hello, I have a 1996 King quad 300 4x4, it would not start at first, charge battery, installed new plug, and changed oil, removed carb checdked and cleaned, foudn no debris, reinstalled, started, but very rough idle, off idle its okay. Will not idle, idles for a bit then dies, will also backfire. Purchased a carb rebuild kit, installed and still doing the same thing.

Found on other threads, the petcock leaks into the vaccum hose, checked with a vacuum pump, petcock leaks, removed from carb and plugged port, still runs poorly, and idle issues still there. removed fuel pump found debris inside, cleaned and out on a fuel filter.

Anyone have any other ideas to try on this thing? Also it fouls the plugs, I think i got the rich running fixed with the vaccum leak.

Thanks for any help or ideas.

[GEARHEAD01]

i would check for vaccum leaks with the quad running. spray flammable carb clean around the engine and all poss points of leaks. if it boggs you found your leak. after you fix the leak then reset your carb.

[DirtDemon]

When you cleaned the carb did you take it completely apart and clean every single nook, cranny and hole? There are alot of passages, and all of them need to be completely clear. Another common mistake people make is when they put the pilot screw back in, they screw it all the way in. This screw has a needle shaped end and has a spring on it. It should be turned about 1 1/2 to 2 turns out from seated. This screw being improperly adjusted could very well be your problem. You should also check your valve lash, not only could this be the source of your problem, but it is generally a good idea to check the vavles when you buy any used machine. Good luck.

[willarid]

I blew air and scrapped every hole in the carb a couple of times, then put a carb kit in, still didnt change much, I tried different settings on the screw(which is outside the float bowl, under the carb at front) from all the in, to out and everywhere inbetween. If I put my hand in front of the carb slightly it will run much better. How do I adjust the valves on this engine, does the top of the head have to come off?

[GEARHEAD01]

if you put your hand in front of the carb you restricted the air flow. If it ran better from that then i would say you have a vacumm leak somewhere. i would take a close look at the intake boot from carb to engine. use carb clean and spray all of the areas that could have a leak after you put you air filter back on. if it got better when you blocked some air flow then the valves are most likely not the problem.

[DirtDemon]

There are round inspection caps on the front and rear of the valve cover that you can remove to check and adjust the vavle lash. Check the vavles with the motor at TDC on the compression stroke, this will leave the vavle springs unloaded. Slip a feeler guage in between the valve stem and adjuster bolt, the size of the guage that fits snug, but not tight will tell you what the adustment is at. If they need to be adjusted, then you loosen the jam nut around the adjuster screw and move the screw up or down to loosen or tighten the vavles, then, without allowing the adjuster screw to move, re-tighten the jam nut. You may need to refer to the owners manual or a repair manual for proper valve clearance specs.