12U Briggs and Stratton Engine - Overview

Models starting with 12U

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Kit-needle/seat – Part Number: 398188
$11.95
In Stock
Kit-needle/seat
Part #398188
Genuine manufacturer approved carburetor needle valve for lawn and garden equipment engines. This item includes the seat. The needle valve opens and closes to control the flow of fuel into the carburetor. Make sure to disconnect the spark plug wire and drain all gasoline from the carburetor and fuel tank before starting a repair.
Engine Recoil Starter Assembly – Part Number: 497680
$88.95
Special Order
Engine Recoil Starter Assembly
Part #497680
This authentic OEM starter assembly is designed for use with lawn and garden engines and is sourced directly from the original manufacturer to ensure quality and compatibility. The assembly includes a durable plastic shroud/housing, starter pulley, recoil spring, pull rope with grip, and the necessary hardware for installation. It functions as the primary mechanism for manually cranking and starting the engine. To complete the replacement, you’ll need a wrench. Simply remove the four screws and nuts securing the old starter assembly, then install the new one using the included hardware. This item is sold as a complete individual assembly.
Engine Breather Gasket – Part Number: 699833
$9.95
Special Order
Engine Breather Gasket
Part #699833
Jet-main – Part Number: 497466
$31.95
Special Order
Jet-main
Part #497466
This is a genuine Briggs & Stratton replacement part. The main jet is designed by the manufacturer for use in engines such as those found in blowers and lawnmowers. This part is made of metal, and comes with a plastic gasket. It is used to control the flow of fuel in the carburetor when the engine is running. You may require a wrench when replacing this item.
Shaft-Throttle – Part Number: 493267
$30.95
Special Order
Shaft-Throttle
Part #493267
Head-cylinder – Part Number: 590411
$82.95
Special Order
Head-cylinder
Part #590411
Retainer-Gov Shaft – Part Number: 690340
$7.95
Special Order
Retainer-Gov Shaft
Part #690340
Seal-oil – Part Number: 399781S
$13.95
Special Order
Seal-oil
Part #399781S
This is an authentic replacement part manufactured for use with small engines. Seals can deteriorate overtime, and it is recommended to replace worn seals when servicing an engine. This seal is the lower seal in the engine's sump, the seal is sold individually.
Key-flywheel – Part Number: 222698S
$5.95
In Stock
Key-flywheel
Part #222698S
This is a Genuine OEM replacement part used on a variety of Lawn and Garden equipment. The key helps to secure Flywheel in place. This is a Metal Key and it is Sold Individually. You would need Pliers to replace this item.
Filter-pre Cleaner – Part Number: 273185S
$8.95
Special Order
Filter-pre Cleaner
Part #273185S
The pre-cleaner filter is an authentic OEM replacement part and is specially designed for use with Briggs and Stratton lawn mowers and small engines. This filter provides an extra layer of filtration to remove dust and debris from contaminating the engine. Made of a high-quality foam this part is sold separately.
Rep Man-1 Cyl L-hd – Part Number: 270962
$51.95
Special Order
Rep Man-1 Cyl L-hd
Part #270962
This is a genuine item that is supplied directly from the original equipment manufacturer for Briggs and Stratton engines commonly installed on lawn and garden equipment. The repair manual contains easy to follow step-by-step instructions, diagnostic methods and other useful information to keep your engine running at peak levels. It is the manual that is being utilized by authorized Briggs & Stratton service centers. Keep in mind this high-quality item is sold individually.
Pin-piston/std – Part Number: 298909
$15.95
Special Order
Pin-piston/std
Part #298909

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starter rewind cord broke
15 of 22 people found this instruction helpful.
  • Seikai from MARICOPA, CA
  • A Bit Difficult
  • 1- 2 hours
  • Nutdriver, Pliers, Screw drivers, Socket set, Wrench (Adjustable), Wrench set
I found the model number of the Briggs & Stratton engine on the inside of the engine housing. Ordered a new starter-rewind unit, as the old cord broke and the thing was well worn. The instructions were clear enough, but to get the old starter off I had to drill out four rivets, which just spin around when you try. I used a hacksaw, chisel , pliers, whatever worked on each rivet; this took a while. When they were finally removed, the new starter pull unit was relatively easy to install with the small nuts and bolts provided. On the Yard Machines log splitter, putting back the engine housing is quite tricky; you have to jostle the thing into place, get the pull handle above the cover and line up the bolt holes.
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Mower body was die cast and in good condition. Engine was burning oil.
5 of 8 people found this instruction helpful.
  • Robert from TEGA CAY, SC
  • Really Easy
  • More than 2 hours
Removed engine, no specialty tools required. Honed the cylinder, and lapped the valves. Tip on compressing valve spring for reassembly; compress springs with you finger and tie them with 2 zip ties, cut the zip ties after installing the keepers. Repainted the mower deck and engine. It runs and looks like new. My Toro is a 1999 model .
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Leaking gaskets
4 of 12 people found this instruction helpful.
  • Dustin from BANGOR, ME
  • A Bit Difficult
  • More than 2 hours
  • Socket set, Wrench set
All the gaskets needed to be replaced on the Briggs 6.75 flathead I was rebuilding. I ported and polished the ports and shaved the eyebrow between the valves and the piston. The gasket set was a perfect fit. It is a monster now. It doesn't sound like a lawnmower engine anymore
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