Heyall, I'm super stoked to say I bought myself a new bikes yesterday, and naturally had to join the forum!
I'm a farm mechanic and have restored and repaired every kind of machine there is, almost. But other than some CT70s, I have never done any mods or real tuning on "lawn mower engines".
I picked up a 2021 Coleman CT200U-EX. The previous owner seemed to take good care of it, but also had no idea what he was doing with regards to tuning and mods.
If I had to guess, he bought an Amazon kit to replace the carb/intake and exhaust. I was able to start the bike and drive it, but it is running super lean, and needs full choke to keep running, and is a PITA to start. The spark plug is nice and white after a short rip around the barnyard.
I was hoping someone might be able to provide me with some tips on where to start with tuning. Other than the carb and exhaust I mentioned, the governor has also been removed. Otherwise the engine is stock. I also ordered up a torque converter for it, but I don't have plans for any further mods at this time.
The carb is labeled CX25, which I assume is a Chinese Mikuni for the predator engine. This I think: https://www.amazon.ca/VENTOMO-Carburetor-Performance-VM22-3847-Predator/dp/B0B8CWG471?th=1
Based on these mods, is there a good starting point as far as what jets to run? I removed my fuel bowl, and the primary jet is labeled as 125. There is nothing stamped on the pilot jet. I really just want to make sure i'm in the ballpark for jetting... no point in getting into fine tuning if it's all out to lunch.
Appreciate any advice, thanks!
I'm a farm mechanic and have restored and repaired every kind of machine there is, almost. But other than some CT70s, I have never done any mods or real tuning on "lawn mower engines".
I picked up a 2021 Coleman CT200U-EX. The previous owner seemed to take good care of it, but also had no idea what he was doing with regards to tuning and mods.
If I had to guess, he bought an Amazon kit to replace the carb/intake and exhaust. I was able to start the bike and drive it, but it is running super lean, and needs full choke to keep running, and is a PITA to start. The spark plug is nice and white after a short rip around the barnyard.
I was hoping someone might be able to provide me with some tips on where to start with tuning. Other than the carb and exhaust I mentioned, the governor has also been removed. Otherwise the engine is stock. I also ordered up a torque converter for it, but I don't have plans for any further mods at this time.
The carb is labeled CX25, which I assume is a Chinese Mikuni for the predator engine. This I think: https://www.amazon.ca/VENTOMO-Carburetor-Performance-VM22-3847-Predator/dp/B0B8CWG471?th=1
Based on these mods, is there a good starting point as far as what jets to run? I removed my fuel bowl, and the primary jet is labeled as 125. There is nothing stamped on the pilot jet. I really just want to make sure i'm in the ballpark for jetting... no point in getting into fine tuning if it's all out to lunch.
Appreciate any advice, thanks!