HELP!! fouling plugs

[cincy250R]

ok here is what's going on i have an 86 250r today i went through 3 plugs in a matter of 6 hours of riding i took the reeds out and they look a little gappy like i can see light where the fuel goes through then i noticed a knock and i took the top apart and the rod moves side too side about 1/2 inch each way..... when ever i take the plug out it's soaked and BLACK... it has always fouled plugs just not this bad....but i'm begining too think that it was the crank seals or the oil seal on the water pump since i read that when i searched......i was just wondering what else there is too check or any advice..... could my spark be too weak????

bored .60 over
stock header
fat boy silencer
stock carb with 145main
48 secondary


thanks
-Dave

[parttime]

side to side play is normal as long as you dont have up and down play on the rod bearing altough a 1/2" might be a bit much.most 250r's have a little knock noise to them sounds normal in your case.either your jetting is way off or you are low on compression to keep fouling plugs or your carb is starving for air due to dirty carb or filter crank seals would cause it not to run at all or it could cause it to run wide open on initial cranking

[Aceman]

Your reeds should be flat, so they seal, not bowed up at the edges allowing air/fuel to blow back out. As for the side-to-side play on your crank, use a feeler gauge and measure it down between the rod and crank journal. It should be no more more than 1.0mm or .040in. It sounds like you need a complete rebuild. After which would be the time to mess with the jetting. But right now you could have bad crank seals causing you to foul, so it's best to fix everything else first then see if you're still fouling plugs.

[cincy250R]

yeah the way the crank moves is not normal at all and i'm going too do a complete rebuild new crank and rod but i was just hoping too figure some stuff out before i it goes back together

Thanks
-Dave

[cincy250R]

alright everything is rebuilt and runs good but still fouling plugs like a *****.....i put new reed, crank seals & bearings, mech seal, brand new top end with weisco piston, i was thinking of messin with the air/fuel screw but i don't know if that's the problem i need help!!!!!

-Dave

[86 Quad R]

before you do anything, you need to make sure that the float needle is in good shape and that the float is adjusted properly.

as with any fresh build, it's wise to do a leak down test to make sure that there isnt any air leaks anywhere and that the engine isnt drawing tranny oil into the crankcase.

once this is done you need to do an across the board plug chop, reading the plug color. the color of the plug will tell ya which way to go with your jetting. if your arent too familiar as to how this works, do a search. there is plenty of info on it here or go here.

CARB JETTING (http://www.duncanracing.com/techfaq/Tech_keihin-carburetion-jetting.phtml)

[cincy250R]

ok well i take the plugs out and they are soaked and black as hell and smell like straight fuel what gets me is that i have a smaller jet in it than it had in it stock and i don't have anything too do a leak down test

-Dave

[cincy250R]

anyone????

-Dave

[Antony250R]

I had the same problem. My pilot jet was 2 sizes too big. Where is your needle clip at? Try moving it one step leaner.