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Simplicity 728 / Briggs 191701 Governor/throttle


fisherman1122

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Hi Guys, 

I was given a Simplicity 728 that wasn't running.  The engine is a Briggs and Stratton 191701. I replaced the ignition system and carburetor and it now runs great.  The issue I am having is that when the throttle controls are attached to the governor level with the spring the engine revs very high regardless of the throttle lever position.  If I remove the control plate and the spring and just have the governor lever attached to the carb butterfly, the motor idles great.  So either I have the wrong spring or I am missing some parts in the throttle/governor assembly.  The parts diagram for the engine make it hard to tell how everything is supposed to be set up.

Here are some pics of the current governor/throttle system.

IMG-2332.jpg

IMG-2334.jpg

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So found the problem.  When the throttle plate is assembled it prevents the governor lever from going all the way forward and prevents the engine from idling.  I have a new throttle plate and lever on order so hopefully that takes care of the issue.  Until those parts arrive, I am going to modify the plate to allow the governor to function properly.

Lever.jpg

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2 hours ago, dhoadley said:

I'm looking to rebuild one of those engines. Can you share where you got the replacement carb? Thanx, Dave

Dave, I ordered this carb: 

https://www.ebay.com/itm/263443463998?chn=ps&norover=1&mkevt=1&mkrid=711-117182-37290-0&mkcid=2&itemid=263443463998&targetid=1068833133739&device=c&mktype=pla&googleloc=9017451&poi=&campaignid=11615951275&mkgroupid=116843212927&rlsatarget=pla-1068833133739&abcId=9300457&merchantid=6566394&gclid=CjwKCAiAxp-ABhALEiwAXm6Iyf7-ghNvrvZ48EkpnfmUO6FzUNVoySK8WV7mUDrmvnT6AvFMt1NHYBoCBYMQAvD_BwE

The carb is very close.  The only difference I found is the choke lever is on the opposite side so you have to reconfigure the cable routing.  I was able to add a cable clamp to the support arm and use that.  The down down side of this is the choke lever on the tractor now travels half of what it used to.  If you need me to, I can send pics of the new cable set up. I can fix that by adding another hole in the choke arm.  I did find the exact part number of carb but the cheapest I could find it was $120.

I am considering pulling the components out of the new carb and using them to rebuild the old one but thats more of a summer project.

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10 hours ago, fisherman1122 said:

I am considering pulling the components out of the new carb and using them to rebuild the old one but thats more of a summer project.

Not to burst any bubbles, but the shiny new chinese carb parts usually do not fit the old Briggs carbs. You will need to get a Briggs or aftermarket Briggs rebuild kit for rebuilding your old one.

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Okay finally got to the bottom of this.  My new carb was the issue.  The lever on the butterfly valve was too long so the butterfly would close all the way at idle.  I put the original carb on and it ran decently.  I have a carb rebuild kit ordered and hopefully that will resolve my carb /governor issues

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