# briggs and straton throttlin up and down



## lab48187 (Aug 16, 2008)

i have a briggs and straton 3.5 hp classic throttle free design mod 9d902 the mower starts up fine but while running it idols up and down it wont stay at a steady pace. eny ideas what the cause or solution might be ??


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## 30yearTech (Sep 14, 2006)

I would recommend following this advice previously posted from geogrub another talented and helpful member of this site!

"You need to install a new diaphragm kit, it is Briggs part # 795083 or old # 495770 also Lowe's has a kit #5083 which has the same parts.
Here we go;

Remove air cleaner, there are 2 bolts that hold things together, one on the front of the tank 3/8" and one into the block 1/2", remove these bolts, now "slowly" slide the carb/tank off the intake tube and breather tube, now tilt the tank in to release the throttle linkage and waalaa the carb/tank is removed. Remove the 5 screws from the carb/tank remove carb(don't loose the spring) now spray all holes, cracks and crevasses in both the carb and tank surface with brake parts cleaner, remove the main screen(looks like a thimble) with a small screwdriver pry out the main jet(carefully) and clean it, reinstall the jet, it can be difficult some times to get it to snap back in place(I use the rounded end of a screwdriver handle). Remove and clean the fuel pickup stem. Clean any junk/rust from the tank. Install the diaphragm on the tank then the gasket(no goo or sealer) now carefully replace the carb(the spring will try to misalign the diaphragm), tighten all screws a little at a time so as not to crimp the diaphragm until they are all tight. Install the carb/tank in reverse order and you are done. If I missed something one of the real mechanics will correct me. Have a good one. Geo"


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## lab48187 (Aug 16, 2008)

well tried it but still doin the same thing. is there somewhere i can buy a new carb?


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## 30yearTech (Sep 14, 2006)

Try this site 
http://www.jackssmallengines.com/index.html


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## lab48187 (Aug 16, 2008)

I got it i went back and took the main jet out and cleaned it, forgot first time runs like a champ starts on first pull, thank u so much 30


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