suzuki lt 50 caruretor problems

[iash101]

Hi there iv just removed the three restrictors on my sons lt50 quad.iv also put in a new piston kit,spark plug iv also replaced the standard air box with a k£n cone filter and put in a larger main jet from a 57 to a 70. ever since doing this im having problems with the engine nearly cutting out and then it builds back up to idle speed ,it only happens after running at 3/4 to full throttle.iv tried the needle jet in all postions with no real difference.
Does any one have any thoughts on this problem as im pulling my hair out!!!!
Regards iash101

[2 stroke dirt]

Go back to a smaller main jet... after changing the main jet from 57 to 70 which is a really big jump when it comes to jetting, your most likely running too rich... a good way to test is to warm the bike up then ride it wide open throttle for a minute or so then shut it down by pulling in the clutch and hitting the kill switch... then pull out the spark plug.

if its wet or black your running too rich (too much fuel)

If its white your running too lean (too much air)

the desired color is a golden brown...