Small Engines (Lawn Mowers, etc.): Toro GTS 6.5 hp intake valve sticking open, universal problem, intake valve

Question
How do I stop my intake valve from building varnish, which results in the valve sticking open?

I'm using clean, new gas. After I cut my front lawn, I have to tear it down clean the valve and put it back together before I can cut the back.

I went to the Toro site and they say new gas, new gas, new gas. This seems to be a universal problem with Toro's.

Answer
Hi Wayne,

You could try another brand of gas or add a cleaning type additive.  The valve should not be that fussy though.  I would suspect some leaking around the valve stem, at the guides.  That may be something that you can't remedy.

Let me know how you make out.
Michael