Alright.. so the back story i have a 02 vinson that ran great and one day i went to crank it and it was making a noise i can only explain as a gear spinning. Well it was the little half gear(shifting gear) had broken off the cast of the block.. from my understanding is its bot uncommon... so i run across a 03 that had been sitting so long the front end had rusted off. So i check to make sure it would turn over and sure enough it did. I only gave 150 for the whole thing.. so i get it home pull the motor slap it onto mine pull the carb clean it install a new jet kit with needle.. the whole shabang alright it... i get it up and running it had a little chatter no big deal.. so i pull it out of the shed and putt around runs and pulls good go to open it up it boggs down almost like a limp mode. So I get out and adjust the fuel to air ratio thinking maybe I didn't set it right it's fine it doesn't no matter what so then I started second-guessing the carburetor try to take my other one and put on it same thing so then I'm thinking maybe it's the CDI box or the voltage regulator I pull the ones off the other one same thing I'm stumped I don't know which way to go with it any help would be greatly appreciated

 

I don't know if it can happen on the Vinson, but Eigers are prone to a magnet coming loose on the flywheel, gives a misfire at first, but can end up with magnets jamming on the stator and the whole lot disintegrating, showering bits of magnet all over the engine's insides.

 

they only thing that stumps me is i can get on it and putt around open it up to about 10 or 15 mph and it runs great and will pull like a new one but anything past that throttle it spits and sputters and boggs down

 

If you have changed the plug, coil and CDI, all that is left is the alternator, so take the cover off, check the flywheel magnets and, if they are OK, swap the stators.