On Mon, 07 Feb 2011 23:29:52 -0500, LSMFT wrote:

wrote:
On Mon, 07 Feb 2011 19:59:43 -0500, wrote:

Taylor wrote:

My snow blower has a Briggs& Stratton 7.5 hp "Powerbuilt Snow"
horizontal engine. It has always need a little choke to run smoothly
after it warms up. With no choke it runs, but stumbles slightly. With
one click it is a bit smoother, and with two clicks it runs the
smoothest. More than that, there is too much choke and the engine will die.

Thinking that perhaps something is clogged in the carburetor/jet, I
replaced the whole carb with a new one. The result is exactly the same.

I have fresh gas, use Sta-Bil, etc. I'm not overly worried about it, I
just use two clicks of choke for best power.

However, I suspect that I'm not getting the full 7.5 hp with the choke
restricting air intake. I'm also curious what the problem is. A
repairman said that all engines are tuned lean due to EPA rules. Of
course there is no way to adjust the mixture.

Any ideas what causes this? Is the repairman right about the mixture set
overly lean on purpose?




Find the fuel adjustment screw. Open it just a touch.
Real good idea, except that particular carb/engine doesn't have one.
Same on a motorcycle. You have to drill out some metal to get at the
adjustment screw.
No, unlike the motorcycle, and early emission carbs on cars, there IS
NO SCREW. Get that through your head. NO ADJUSTABLE JET.