I have an NC50 and it is powerless compared to my QT50 and only tops out at 25mph.
I don't believe the exhaust is plugged but could be wrong.
I may take a compression check tomorrow but it starts and runs very good except for being very could blooded.
I have the ability to modify most any part so I'm not above some serious souping up. I looked into custom exhaust but have yet to find any, may need to make my own. I also am considering grinding the ports but don't know how much to remove. So far Ive never had the engine apart or even had the exhaust off.
I guess my question is -what can I do to greatly improve power and top speed? I like the Honda much better then the Yamaha except for the slow thing.