125-200cc 08 cr125 bog

Mine had some mid bog with the Mikuni carb. One certain days the jetting was spot on and it rode beautifully. On a different day with similar temp, the bike could be finicky due to the carb. I ended up putting the PWK 38mm air striker with JD jetting (from Motosportz). Now, I do not have any issues with the low & mid range.

The Mikuni carb works fine on top. It's just how you get there. I did experiment with Walt's PV spring kit. It works very good at covering where the Mikuni lacks. Right now, with the PWK, I'm actually running the stock PV spring with good results.

I would say that the '09 bikes suffered more initially due to the PV valve and exhaust pipe. The Mikuni only made things worse. The '08 bikes suffered only due to the finicky nature of the Mikuni. Some folks like Ajaxauto with his '08 had no issues, so the riding region may be a factor here too. I do believe the '08 CR125 minimizes the mid bog since it revs much easier than the WR's. That is, you can "punch" through the bog zone since the engine spools up quickly as you dance through the gears.

Race gas really helps & even sometimes cures the bog,I know alot of people dont like to spend the $$ but it really helps. {Doma pipe works awesome also but very hard to get or even find in this country anymore.billf