1990 cr125 help

Mar 29, 2011
101
1
44
Yorkville Illinois
i just recently got a 1990 cr125. it has a BRAND NEW top end with about 2 hours on it. When i first got it the carb just poured out gas from the drain vent. I took it apart cleaned it, reset the float and it fixed it for about 10 min... then while riding it bogged down and died. The plug was fouled so i put a new one on. Same thing. So i need to fix the carb and the bogging! help
 
go a size or 2 smaller on the main jet. should fix it.. what ratio are you mixing ur fuel.. mix to 40:1.. 32:1 in a 125 is way to thick and will bog the bike
 
my 05 kx125 modded race bike (now training bike) is on the original piston and bore from when i first built it in 05, i just re-ring it once a year. it runs on nothing but a 50:1 mix of maxima super M and premium pump gas.. i ride the piss out of that bike and no issues of over heating cracking skirts or seizure, ive rode everything from arenacross races to loretta lynns on the same exact fuel mixture and set up never a single failure, if its jetted and running correctly the clutch will fail before the topend on a 125
 
Check the sticky on "Almost free carb repair" Good tip on cleaning needle seat. If that doesn't work you'll need a new seat and needle. DON'T go changing jets till you have that problem fixed. How do you know it needs leaner jetting?