This should be the link to the manual, my 6.5 is OHH65.
http://www.tecumsehpower.com/Custome...uals/index.php
I get a .pdf that covers 5.0 to 6.5 hp
Also look at this manual -
http://www.yerf-dog.com/manuals/3203A_T.pdf and then look here
http://www.yerf-dog.com/service.gokart.html it shows an RN4C
xlint89 - I still agree with you !
I had (2) 6.0 and (2) 6.5 Techumseh off various karts I bought (all in bad shape) and could only get 1 to barely run, after many, many hours. I did the carb clean/ new gaskets, etc., but I'm not good with engines. I finally took one to my local small engine shop, and 120$ later it ran ok, and I have no clue what he did. For those of us that are missing the engine gene, the HF $99 is the best way to go. (especially in my case with 2 grandsons saying "when papa? when papa ? )
I am happy to report that I just got my trashed out GY6 to run ! WOOOHOOO ! Maybe my small engine gene just needed keep reading this forum till I got all the wires right !