So I buy this old MTD 826 that I literally dragged out of a barn. Been sitting for a very long time. Got it running with a minimal amount of work and it would rev up and down with the throttle lever but would not stay running and it hunted horribly. So I get a new carb that is exact match and install it. Runs fine but it will not rev up. It just idles. I put the gov linkage in the same hole. Tried adjusting it but no change. What the heck?