Black plug

[benno200]

just a quick qeustion
I have a 2002 blaster which mixes the oil automatically,but my plug is black and wet, i have replaced it ,and within 30min it goes again and runs rough,i have the right plug and have turned the air-mixture 1 and a half turns out...

does anyone have ideas plz?

 

[ron89]

what oil u running ,and what octane gas u running ?..

 

[benno200]

texaco unleaded 95
oil is castrol as i remember

 

[dblaster]

cleaned the carb lately?

 

[benno200]

yes had it apart cleaned jet and drained the pipe etc

 

[89custom]

hmm, should i be worried if my plugs a bit on the dark side?

 

[Chevy1500z71]

a perfectly jetted bikes plug will look like a nice toasty brown, maybe a litle black around the edges. a black plug means your a little rich, taking your airbox lid off could be enough to use that extra fuel, or the right way wold be re jeting it. having a bike run rich is never a big deal on a 2 stroke but dont EVER let it run leen, if the plug looks grey(leen/overheeted), dont even ride it, jet if fatter.

 

[benno200]

ok cheers mate
gonna try it tomorrow (sunday) with another new plug and the air-box lidd off
the only thing i can adjust form what i can see is the air-mixture screw so ive done the 1 and a half turns out

 

[benno200]

TOOK QUAD OUT ,REMOVED AIR BOX LIDD,TURNED AIR SRCEW AND BOUGHT ANOTHER PLUG...
RUNNING GREAT..
THANKS FOR YOUR HELP GUYS
NEXT STEP TO FIND A PIPE FOR IT

 

[Chevy1500z71]

good to hear that its runnin good. just make sure you get around to checking and making sure the plug is a nice toasty brown just to confirm that the jeting is correct.

 

[quam]

runnin that high octane might be restricting your combustion too......i'd recommend runnin the lowest octane you can get.
blasters have less than 7:1 compression ratio.

 

[hickskateboarder]

i dissagree. static compression maybe less than 7:1, but dynamic is likely much greater. with the way the engine and exhaust is made to kinda "supercharge" it, its probably between 9 and 10 to 1, from what i've heard.

 

[cmattox23]

so can somebody help me figure out what the problem is with my friends 06 yz125? same deal, runs fine on a brand new plug, but after a hour or two of riding, she wouldn't start back up. I took the plug out and it was ridiculously wet and black..

Any and all help will be appreciated.

 

[hickskateboarder]

sounds like the jet is way too big. is it stock? either get some smaller jets, or get some performance mods! although, check the air filter. make sure its not real dirty. actually, just clean it, never hurts, buy an aftermarket if he doesn't have one. idk if the stock airbox on a yz125 is very restrictive or not, but you may want to drill some holes in the lid. my friend just bought a used yz250, it had holes drilled all thru the airbox, so someone must think its restrictive lol.

 

[cmattox23]

lol alright..i appreciate the help..now i just need to know how to find out how big the jets are in his carb..lol

 

[hickskateboarder]

take it out and hopefully it will have a number stamped on it... i'd try cleaning the filter and drillin some holes in the airbox first tho. unless he goes muddin with it or something.

 

[cmattox23]

na he doesn't..i'll try that first though..thanks a lot

 

[hickskateboarder]

lemme know how it turns out.