calling jetting gurus!!!

Budget_Blaster

New Member
Dec 25, 2009
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Illinois
Ok i been laid up for a little bit after a trip to the badlands and a dumb ass stunt on my kdx i attempted a superman all was well until i went to land it and the bike some how ended up on me.

Anyhoo so now im gimping around and decided to have a go at the tuning of the 240bbk on my blaster since it was nice today.well i take it out as it is with a 290 main which a month ago was too much and caused it to bog fast foward to today and i take it out it ran great then died.ok no problem it fire right up and i took back home well when i got there it was acting funny and didnt wanna idle so i shut it off and realized it was hot.the packing was smoking so i yanked the plug and it was lean i checked the piston and the crown looks good so i decided what the hell ill throw the 340 in it since its 72 degrees as opposed to the 45 last time i tried tuning it and holy hell!this things a beast i literally couldnt keepthe front hoops down its crazy!

So my question is were my problems just the weather or should i check into something i rode it all afternoon with no issues its idles and is a monster.i do have the stock jet needle back in the carb per kens request on the very last clip and i have the sst2 header and silencer on it.

I know weather greatly effects jetting especially on a 2 stroke but thats insane if this was really all over weather.what do you guys think.ive not done a plug chop yet and was just buzzing up and down the fields acess road behind the house but plan to asap.with the 290 it was chalky grey way to lean.
 
might have to take the head off...your bike always runs at its best right before it blows...running it that lean might have done enough to do a little damage...to be on the safe side take it apart and see whats up
 
Nah i checked it out looking down in the plug hole and it looked good when i did the retorque after the heat cycles.

I also did a compression test and its still hitting 180 psi so i doubt i got issues.

But i find it odd i put the 340 back in it after rebuilding the entire engine due to a broken case halve on the right side and it runs like a dream when all thats changed is the temp.im even using the same tank of 93 and amsoil so i dont know.