Need Help with 1980 elsinore

[MXmonkey]

i have a 1980 CR 250 and i just put a new weisco piston and a set of rings in it and now when i ride it after about 45 minutes it just burns the plug up and it lose's its spark i mix my gas at 50:1 ive tried mixing at 40:1 i started out using a NGK B8ES spark plug then i moved up to a NGK B9ES and i even tried a resistor plug that was some weird NGK number and my needle valve is on the top notch please help thanks

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dont get weeded!

 

[Oregon Trail]

Are you fouling the plug? Can you put a new plug in and go? In a NGK plug, an 8 is a hotter runner than a 9. Did you have the same problem before the piston and rings? If you're able to just put a new plug in and go, sounds like just re-jetting. Hopefully you aren't sucking up crankcase oil.

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91 KDX250
81 HUSKY 430 XC
72 HUSKY WR 250
72 HUSKY WR 450
73 HONDA XR 75 (MY ORIGINAL BIKE!)

[This message has been edited by Oregon Trail (edited 03-07-2001).]

 

[MXmonkey]

yeah i'm not fouling the plug it just wont spark anymore even if i clean it up. i can just pop in a new plug and it starts on the first kick. it never did this before i put in the new ring and piston. thanks for tellig my about the NGK plug i thought that a 9 was hotter than a 8. how would i tell if i was sucking up crakcase oil???

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dont get weeded!

 

[Oregon Trail]

Yeah, sounds like you are fouling the plug. I've never had any luck in trying to clean my plugs after I foul them. Do you have to keep adding crankcase oil? If you do you may be sucking it up via a blown crankcase seal. If you don't have to, I'd try going with a smaller pilot jet first. Sounds like a case of running too rich.

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91 KDX250
81 HUSKY 430 XC
72 HUSKY WR 250
72 HUSKY WR 450
73 HONDA XR 75 (MY ORIGINAL BIKE!)

 

[MXmonkey]

Thanks i'l tell my dad and we will check the crank case. what would you suggest mixing my fuel at?? thanks

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dont get weeded!

 

[OnAnySunday]

My '79 YZ-400 had a similar problem.
It was jetted too rich.
I put in a set of Boydsen's "torque reeds",
and jetted accordingly.
But it still chewed up plugs (NGK B8es or B7es) quite often, so i tried some different plugs.
Seems the ol' gal didn't like NGK's anymore.
It ran much better and longer using Champion N2C's or N3C's.

Who woulda thought???