Old 13HP flathead throttle/governer problem

I've got an old Briggs 13HP flathead that there's no throttle adjustment. I can live with it when engine is cold & it runs fine for mowing. But when the engine is hot and I disengage the blades it revs up too high. The governor spring was broken & I replaced it but didn't make any difference. i checked the governor set up and is fine. I was told it must be the carb but not sure about adjusting it & don't want to start until I get another opinion.

There is an adjusting screw that limits how far the carb butterfly closes. Is it adjusted to where the butterfly will not close far enough? It is on the lever where the governor rod connects to the carb butterfly arm.

I can send you a Service Manual which will show how the throttle control works. A few engines made for powering generators are fixed speed but can be converted. . Address below, put in proper format and remind me engine model number and what you want IF you want a Service Manual.

Walt Conner
wconner5 at frontier dot com

Thanks for the tip - never thought of this. I adjusted the screw with the throttle on low until revs dropped.
the throttle is now adjusting - I'll have to wait for a fine day to see if it runs ok while mowing and engine hot conditions.