Bought the new ex27 robin engine.

[mdj89]

How will the ex27 engine do with two adults riding. lets say 364 pounds total. when I rode with a passenger with the stock tecumseh motor, It moved real slow.
It was almost like you could jog right next to it. lol

 

[r_chez_08]

Should be OK, probably best not to gear it for more speed though..
Can I suggest you get a cheap RPM gauge-This way you can tell if your engine is actually revving to it's full potential. If the kart was going at jogging pace either your engine was struggling and could not rev to full RPM or there is a problem elsewhere.