Briggs carb problem that I caused!

[Mad Mackie]

Hi Troops,
My 2008 Scag Tiger Cub has a 30 HP Briggs Commercial Turf that I installed several years ago. About six weeks ago I removed the blower housing, cleaned under the flywheel, around the cylinders, around the carb and air filter housing with HP air from my compressor and put it all back together. As we haven't had much rain, conditions are dry and dusty.
The engine RPM at idle has been increasing and I decided to find out why!!!
Long story short, while blowing air around the back end of the air filter housing, I popped the crankcase breather tube out of the filter housing. This caused an open hole directly into the carb thru which dust was passing. Some of this dust was collecting in the carb bore right behind the throttle plate on the right hand bore. This accumulation continued to buildup preventing the throttle from going back to idle and increasing the idle RPM.
Check out the pics.
I also found that the throttle shaft was difficult to turn, so I removed the throttle plates and pulled out the throttle shaft. I found an accumulation of crud on the shaft where it passes thru the seal.
I have cleaned up these areas and reassembled everything and it now idles at the RPM that it should be!!!!
I have a carb kit and gaskets on order from my local Scag dealer. Their parts man commented that they haven't stocked these parts yet as they haven't had any problems with the Briggs Commercial Turf engines on the machines that they have sold.
Anyway, I'm back running and I will be more cautious the next time I clean this engine!!!
Pic #6 is the back side of the oil cooler, grit blasted somewhat!!!
Mad Mackie in CT:laughing::biggrin::smile:

 

[motoman]

Mackie, No pics??

After about a year owning my Craftsman Intek 24 I was baffled at dirt in the carburetor throat. I had been very careful installing the air cleaner to the upper / lower rubber mating surfaces each replacement. Finally when the engine came apart I discovered the problem . The breather tube from the crankcase to the carb throat had a wrinkle or "pooch" on the inside radius where it pressed into the carb throat. This was invisible to normal inspection and allowed the poor Intek to suck dirt for a year. Why it did not take out the rings I do not know. A quality problem during Briggs assembly.

 

[Mad Mackie]

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