2721H Simplicity Lawn Mower - Instructions

Clean engine with a Gunk type product. Remove valve cover. Loosen bolts and remove old cylinder head. One bolt is located inside valve cover area. Remove old gasket and inspect and clean that surface. Attach new head with new gasket using existing bolts. Torque to 18'#s with a cross type pattern. Attach new rocker arms and push rods. Set valve clearance to .004 - .006. Attach valve cover with gasket. Check oil level. Start and let it warm up. Let cool remove cover then check valve clearance again. Replace cover.

I removed the fan shroud, the carb/manifold as an assembly,turned the carb upside down and removed the fuel bowl. I replaced only one jet. Not until this moment did I discover their were two jets in this nikki carb. I now have a second jet ordered and will install it Friday,hopefully. These jets are two different part numbers as one is a left jet and the other is a right one. Be careful when opening the fuel bowl as these jets are held in their bores by small O-rings, and nothing else. The brigg's and Stratton part numbers are 791501 for the left jet and 791502 for the right.

Removed tank and drained old gas.
Removed and disassembled carb. Needed new gaskets and seals, and had to clean corn syrup glaze (separated ethanol) from bowl and everywhere else with carb cleaner.
Throttle linkage was de-plating/rusty. Steel wool and WD40 got it moving again.
Cleaned spark plug electrode.
Reassembled, poured Sea Foam in the bottom of the tank and gave it a few pulls.
Let Sea Foam sit for a while, then filled the tank with Premium.
Blew white smoke for a minute then ran like new. Shredded for a while, then changed the oil.

Look on YouTube for video's on how to replace a Briggs governor. There are several there. My favorite, with best explanation, is, "Easily Replace Briggs Governor Gear (V-Twin Intek Engine) with Taryl". https://www.youtube.com/watch?v=wn3eanGxSEA&t=152s.

Taryl (probably not his real name) does a very good job of showing step-by-step the whole procedure, along with some additional hints/tricks/techniques of value.

Not including oil and filter, I spent less than $50 for a new governor, gasket, and drive shaft seal. That's all that is really necessary to replace is those three parts. That is, unless pieces of the old governor tore up a gear, valve, or something else. Inspect everything! {I was lucky and only the governor was destroyed}

One word of note. Be sure to clean out all of the debris from the blown governor. Be sure to remove the spark plugs and carefully rotate the drive shaft while looking for nooks-and-crannies where debris can hide. I tried to use a magnet to help, but it didn't help much, even though the block is aluminum.

Good luck.

dissembled ordered repair parts, piston ,upper case, rod, camshaft, seal kit, and motor maintenance CD
The camshaft first provided did not have the compression release device on it and the cam lobe position was all wrong for the model engine I had. .
Parts Select provided me with the proper cam Shaft. Removed engine from mower (Scag Freedom Z) 15 minutes, drained oil, flipped upside down removed bottom case, removed wrong cam shaft, reinstall new valve lifters, camshaft with decompression release on it matching dots on crankshaft. Used paint brush to coat all parts heavily with motor oil.
Do not put sealant on case gasket,(it might change crankshaft end play), retorqued bolt in alternating pattern, placed nylon pipe tape on drain plug threads, and reinstalled engine on mower. It started instantly and ran extremely smooth with no oil burn or vibration.

I am very happy with the support and quick mshipping Parts Select provided..

Using a socket wrench with extension and a T20 star socket (you can use the appropriate hex head socket also) i removed to two bolts holding the muffler on. They are right on top of the engine and very accessible. Your model may have a heat shield that needs to be removed. Once the muffler is off remove the old gasket. It may be stuck to the muffler or exhaust opening on the engine. It should just pry of with a little effort. I did make sure there were no gasket pieces left behind. I placed the bolts through the flange of the new muffler and then slid the new gasket over the bolts. You can use a exhaust gasket sealant just hold it place while you place the flange in place and not have to worry about gasket dropping off. I just held it until I got the flange in place. I started the bolts by hand using the socket and extension. I alternated from each bolt until I had tighted it down. You can look up torque specs. I just used my grunt meter. It is good as new. Parts were OEM replacement. Not knock off almost right parts. I got very lucky when I found this company and will use them again.

Removed old broken rewind starter (4 bolts); found the Model and Serial numbers; found Parts Direct and ordered new assembly; upon delivery, reinstalled with new Starter and hardware.