Got the quad started today. It wont start using the ngk plug by the book with the correct gap but i used a different plug used for my audi that has a hotter spark and it fired up first kick? tried the other ngk that is brand new and it wont start from it? It also does not want to idle, wondering if its running lean? plug was black but it wasnt the correct plug. I dont see why it wont fire off the brand new ngk plug that is correct for the quad

 

maybe your coil is weak and the spark from the NGK isn't hot enough but the one from your audi has a hotter spark normally which might be hot enough even on a weak coil to fire the motor

 

I just replaced the coil, cdi, and stator....

 

BR8EGV
is what I run in my 85 LT250R.

for idle problems, once you get it started, ck the Reed Plates (get some Boyesen), then go for the idle jet.

 

check the plug after running at high RPM (at least 3rd gear) the length of a football field.
shut it off without letting it idle down.
pull the plug...if it is white your running to lean, if it is black it's running to rich (flooding). It should be a light beige color.

hang in there....it's worth it!!!!

 

I appreciate the help. It is running rich bc the plug was real black but it was the wrong plug for the quad. I will have to mess with my air screw, do i push it in or pull it out if its too rich?

 

If idle jet in the carb is to big it will RUN rich. (when @ idle, this makes it "slobber" fuel)
Sounds like it might be a problem with the float and needle seat in the bottom of the carb (gas standing/running out of the carb when you shut it off). This could cause the plug to foul and the engine will not Run.

Did you say you've cleaned the carb?? What type of Carb? Do any work to it?
Is the choke working?? Is the petcock actually stopping the flow of gas into the engine when it's not running?????????

I MUST shut off my petcock fuel valve EVERY time I shut off the engine or the fuel will drip from the carb into the bottom of the engine. It doesn't want to run full of raw fuel!

To answer you question, the air screw turns in for less air, out for more air.
You can count the turns to turn it all the way in, then back the screw all the way out
to flush any debris.

But....you need to find the source of the fouling plug.
Simplified---your getting WAY TO MUCH FUEL.

What breather set up and Air filter are you using?

The exhaust, reeds & filter (air breather set up) all have a big effect, along with carb jet & needle position on determining what minor adjustments can be accomplished with the air screw. (on a functional carb, choke and fuel delivery system)

 

Well, the air screw adjustment is not really "minor"

 

Its the stock mikuni carb. I just put the carb through a carb bath and checked the float levels and everything seems good. was overflowing but i fixed the floats. I think it is my air screw bc i did mess with that, I will have to mess with it and get back to you. So if i pull it out i get more air, should be more fuel to go with that or is it less fuel ? Do i need to push the screw in or out if its running rich

 

Still the simplified answer.
If it is running rich....you need to cut down on the fuel.

When you get the proper amount of fuel, you can tweak the air
more or less as needed.