17.5 Briggs, rpm's wont rise under a load

[rb69]

I have a 2 year old 17.5 Briggs engine on a 36" walk behind. Now it's not increasing rpm's when it gets a load on it from long grass.
Still mows ok, but I'm at a loss. When governor is operated by hand it revs up.
Rod and spring are attached at the carb.
What's the adjustment procedure?

Thanks!

 

[slomo]

from long grass

This ought to alert you in on something.

Might need to cut more often or sharpen slash install new blades.

Post up a video of your machine cutting tall grass. Link it here so we can see and get a better picture of what you are talking about.

 

[bertsmobile1]

Couple of things here
Firstly does the governor arm move when the engine slows down ?