Yamaha TTR 125 BBR 150 Kit

I bought a TTR 125 with the BBR 150 kit already installed. Ran gret for a few years. This spring I tried starting it with no luck after sitting for 6 months. The gas was dark yellow soI drained it and put new gas and it ran. I have an aftermarket KEI carb with a 3 position choke. However after warming up (with the choke on), I get uncontrollable revving and stalling, in any choke position. It also backfires alot. I know another person that had the same issues with the same bike and replaced it with a $30 carb from amazon with perfect results. But with the bigger engine kit will this work? Stock carb is the Mikunoi VM20. Can I put a stock VM24 in it? Im mechanically inclined and could probably tear down and rebuild the engine with exaqct replacements but I'm not knowlegeable enough to figure out the differnt carbs sizes and jets.


Staff member
It's not plug n play, but possible.
You'll have to change both the airbox and intake to fit the larger diameter carburetor port. Also some jetting may be needed to get just right.
I have found (200cc) when moving from 24mm and going to 28mm, the engine will rev higher, but at the cost of low end response/torque. I have not seen much difference with either carburetor.
-BIG DAN:thumb: