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Johnny_Law · May 22, 2009, 06:15 AM

L118 mower with Briggs & Stratton 22HP engine. Throttle does not function. Engine will only increase rev's at 1/2 choke. All mechanical linkages appear to be functioning. Have tried replacing fuel, fuel filter and plugs. Have also tried cleaning the carb, all to no avail. Any suggestions would be appreciated!

21boat · May 23, 2009, 12:24 AM

Not to sound goofy here when you say throttle does not function does that mean the cable isn't moving the throttle body linkage on the crab?

Johnny_Law · Jul 24, 2009, 06:02 AM

(Sorry for the delayed reply) Everything is functioning mechanically. The cable moves the linkage on the carb, and the linkage, in turn, is moving the butterflies, internally. Notwithstanding, when I push the throttle lever, there is no change in engine revolutions. Since the last post I also tried replacing the fuel pump, which did nothing.

crigby · Jul 24, 2009, 06:36 AM

Hi,
Because the "carb" only functions approaching normal at 1/2 choke; that says that there is still some trash in it. It is actually what the automotive industry calls a throttle body. If you look at it off the machine, you will see that full throttle does not open the butterflies much more than idle. It feeds each cylinder off both sides and they each have different jet sizes. This is because of the length of the intake path to each and the proximity of each side to that path. I know that sounds confusing in writing; it is far easier to show someone.
My guess is that a pilot circuit is clogged. Generally best cleaned in reverse of flow.
Peace,
Clarke

Johnny_Law · Jul 25, 2009, 03:32 PM

Thanks, Clarke. I'll give it another go.
John

Johnny_Law · Jul 27, 2009, 03:03 PM

Clarke,
Success! Cleaning the jets in reverse seemed to have done the trick. Thanks for your assistance!
Cheers,
John

rjschulz · May 25, 2011, 05:56 AM

I have the same problem with a L118 almost seems like it has water in the gas. Where is the pilot circuit and how do you clean it in reverse.

Johnny_Law · Jul 27, 2011, 07:20 AM

Sorry for the delayed reply. Don't check the e-mail associated with this account often. The Pilot Circuit consists of a brass pilot fuel jet that extends into the float bowl, the pilot mixture screw, and the pilot air-correction jet near the “mouth” of the carb. The Pilot circuit delivers it's air/fuel mixture through a small hole in the floor of the carb outlet. I first tried cleaning the jets in the direction the fuel normally runs. When this failed to rectify the problem, going on Clarke's suggestion, I cleaned it in reverse (using Gumout spray, I simply put the "straw" over the jets). This seems to have solved the issue. I'd also check the gas cap to make sure that the vent hold is clear. If its clogged, the system won't draw fuel from the tank properly.