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dirt bike help please

Posted: Fri Mar 20, 2009 8:54 pm
by thelastfzr
i know its not a yamaha but i cant figure this out
ok heres the problem put new plug in starts after 5 to 10 kicks rides ok but as soon as i kill it with kill switch it won't start back up. here are the facts of the bike

1997 cr125
fmf turbine exhaust
bored 20 over or two sizes which ever you call it
boysen power reeds
main jet 172 stock
stock needle i tried middle clip, also all the way to top clip
stock pilot jet
brand new pre oiled air filter
br8es plug
premium gas with klotz racing oil, i have also tried supra oil and honda 2 stroke oil

after i run around track pretty hard plug looks ok response is something to be desired i use the kill switch to shut off. then when i try to kick over nothing tried shutting off gas and wide open throttle. once in a while this worked. i did pull pug out and check for spark i do have spark not sure what is good spark and what is week? thanks in advance i am close to taking to a dealer but like to learn myself and not pay a arm and leg.

Re: dirt bike help please

Posted: Sat Mar 21, 2009 12:49 am
by R3TARD
check ur reeds, check ur gap on the plug, run it out and pull the plug and note the color of the plug should be that happy tan. check compression could have a bad ring seat. make sure ur not lean or ull fry that new top end

Re: dirt bike help please

Posted: Sat Mar 21, 2009 8:51 am
by thelastfzr
its been like this the day i changed the reeds i put my hand over spark plug hole and it blows it off strong i have checked gap on plugs and were correct i have gone thru over 10 plug on this problem. i feel i am rich because when i pull plug it is usually wet and black it also gets better when i lean clip on jet needle. reeds said it could richen up to 3 sizes on main, fmf site says i should run a 168 main. im currently runnin a 172

Re: dirt bike help please

Posted: Sat Mar 21, 2009 9:09 am
by abs929cbrrr
172 is not that big up fro 168. disconnect your kill switch...i never used mine on my 1997 cr125 when i had it. a dealer wont charge too much to look at it. i think we need to know how it ran before you put a new plug in, and when it had its last top end job?

Re: dirt bike help please

Posted: Sat Mar 21, 2009 10:32 am
by thelastfzr
ran fine when i bought it late in the summer i lost enough compression to kick start it bump started but i ran a compression check and it had minimal. so i rebuilt and had bored i then changed reed also cause they looked chipped. i replaced with boysen power reeds. ran great 1st time i fired up after it shut off it would not kickstart. i leaned the needle clip and adj air screw new plug ran great. then shut off would not kick start could bump start but no kickstart. more dj on needle and seemed ok once in a while it works fine but 95% no good