When you cleaned the carb, did you check the operation of the vacuum
piston and diaphragm? Is it sticking, or the diaphragm cracked? Needle
loose?

There is no reverse rev limiter, but the CDI likely has a max rev limiter,
and if this is happening at high RPM, then it could be failing, as MERRYMAN
says.

 

Thanks, I've fixed a lot of Chinese brands, but never came across this issue, stator output on one meter is 14, the other meter showed 15.5, needle a tad loose, saw no damage to diaphragm but it appears to be surging up/down every now & then, I'm gonna get a rebuild kit and a cdi as that is what it appears to be based on readings and the advice given.

 

Try rebuilding the carb before getting a CDI. Expensive if you don't need it, and Honda changed the CDI every couple of years on the 300 so getting the right one requires matching the colour and code on the old one.

 

Thank you sir, one more thing I've learned on these machines.

 

Update: waitin on parts, reverse inhibitor limiter checked out good as does brake switch, waitin on new cdi .

 

it is doing fine, the new cdi pretty much fixed it as the choke plunger also gave me fits. Now, it runs great. Thanks for the advice & help