Hi converts!
There is one big difference that I've noticed on the Ryobi engines sold for california and the ones sold outside, if you pay attention to the cylinder head the exhaust port has a retarded timing( this means that the port is lower thant the regular one) thus giving less power I have several ryobis that I've purchased in Yuma, AZ. that perform just about the same but when I bougth one here in California I couldn't reach the same performance as the others beside it was missfiring all the time, so I changed the carb, no change, the plug, no change, the coil, no change, the coil and flywheel, no change, so I was going to disassemble the engine to check if the reed valve was bad that when I took of the muffler I've noticed that the exhaust port looked funny so I then compared it to my other engines ports and guess what? they where different, I then went on and traded cylinder heads and my performance was even better than the other engines by 100 rpm's. so now I will have to travel to Yuma AZ.
every time I need an engine to convert It is only180 miles from where I live besides I will enjoy a leisure drive!!!