250-500cc foueling plugs

does anyboady know the correct fuel/oil mix for a wr 250 o7plate as it keeps killing plugs ive tryd altering air screw/tickover and they dont seem to change anything .carbs been striped an cleand an tickover/air screw still dont change how bike ticks over,could something in carb be broke or could it be rings?has anyone got any ideas that could help thanks j

Hello

Hello! Have you checked your jetting? Fouling plugs does not have to do with the amount of oil you use only. I use 3% in my 300 and i never foul plugs. Take a look in the jetting database and compare with what you have, or write here and i´m sure the guys will help you out!

Johnny

I have a WR 250 and what i thought was a fouled spark plug after about 100 miles of riding/racing WAS a spark plug that i had not gapped I tried everything in my search to find the problem from jetting ,timming,spark plug cap uriudium or stock plug did not make a difference after about 80 miles the problem would start when under full load in 4th or 5th under power the bike would flam out .well started to gap the plugs at 22 and so far it seems to have worked .Raced the first National hare and hound 2 weeks ago where i finished 2 nd 250 mag expert and the bike worked perfect for the full 100 mile race.Rode again about 50 miles over the weeken as still running fine This weeken is round 2 so i will let you know if it keeps working .I chased this problem for over a year but it looks like i might have got it fixed
i was always told not to cap the uridiun plugs but the people at NGK said to carefully cap them so i did .I have used both the stock and uridium plug and both work the same.Never had this problem in my CR 125 maybe it is because the the CR has a better set up then the WR

Hi Jase1
I had the same problem as you, please do look at my post in the 2t jetting data. The 250 has an issue with the float level being set too high from factory.
I reset my float level with some great resaults. I have not fouled a plug since.
Regards Col

thanks lads ive been mixin fuel at 25:1 witch lookin on here seems very rich but its wat dealer said to,jets are standard i will try 40:1 with fuel to start an go from there thanks again

chainged float height this morrning been out for a couple ov hours an so far so good

so what should the float level be?

Use an iridium plug, worth the extra coupla bucks, better starting, better spark, more efficient ignition

i find the iridiums are less forgiving if your jetting isnt 100%


haha extra couple of bucks?

My standard plug is like $1.50, iridium $20 +

bike failed again, but have now narowed it down 2 electrical fault so going to strip down at weekend and see if can sort it