Winter 2020/2021   I bought my Conquest new in 2001 and for the most part I’ve not done anything other than regular maintenance to it or the Vanguard 16 hp engine. Oh, I’ve replaced a starter once, replaced valve cover gaskets twice, but otherwise it’s oil and filter every 50hrs, air cleaner 2-3 times per year, grease the front axle pivot and other fittings, and that’s about it. With 750+ hrs she’s started leaking oil (I think) around the crank seal and #2 valve cover. Oil was collecting on the mower deck and I noticed the loss on the dipstick at each startup.  So I’ll take you through what I found and most of what I did. While the engine was on the workbench I developed a sever pain in my hips so progress was pretty slow. I am blogging this on Sunday, March 21 and its beautiful 71* Missouri day. But, I am playing catch-up cause I started the tear down several weeks ago. 

 Hood pops off the Conquest without any bolt removal. Just disconnect the light wiring harness and lift up with the hood open.  I've owned this machine for 18+ yrs and never knew that. 

Electric clutch removal is cumbersome but not tough. Disconnect the wiring harness, take the center bolt out and drop it off the shaft. Dirt and grime build up 

Unclipped air cleaner cover and removed the filter to reveal nuts & bolts that hold SSM ly onto carburetor.

Air cleaner assembly removed. Air is supposed to move across the heads and fins to keep dust & dirt out but it looks like the engine has probably been running hotter as the buildup is worse than expected. I do blow compressed air around the heads couple times per year without removing tinwork but apparently I wasn’t getting the job done.

 The grand reveal under the blower housing: yuk! Tore it down none too soon. Fins were clogged/packed with oil soaked dust and dirt. Vanguards are known for leaking oil past the valve cover gaskets and I've had problems with one cylinder. Pretty easy to see which one..

Spark plugs look fairy good so the engine is operating fairly well for this age.

I was surprised to find the head gaskets didn't seem compromised and no real buildup around them. So I decided to clean up the fins and not pull the heads. Here you can see the buildup around the spark plug holes

My engine stand was an old Cub Cadet front wheel salvaged from a machine I bout to scrap a few yrs ago. Really worked good for me as I could rotate the engine a full 360* to inspect everything. I found the sump gasket was seeping a bit so that, along with the crank seal may be most of my leaking problem. 

@s_stephen has cautioned me to check Vanguard valve clearance so while on the bench I simply followed instructions by inserting a ✏️ into the cylinder through the plug hole, measuring at tdc then 1/4” past tdc. 

New sump gasket was the most expensive part ($30+) replaced plus there was an o-ring in the sump gasket that added a bit more. This picture is after assembly with only a bit of the red colored sump gasket showing

On reassembly I forgot the governor spring orientation so with the help of my @Chris727 pictures I got them right
When I put repowered the Sovereign I followed @PhanDad instructions to cut holes in the blower shroud and place covers over them for future cleaning. Although I like the feature on the Command, it is not as serviceable as I'd wished because the covers are so close to the firewall on the Sovy. Should be a big + for this vertical engine though so I set about drawing, cutting and jabbing inspection and clean outs hoping I can avert future buildup problemspop

While underneath replacing the electric clutch it's a good time to grease the front axle pivot. I've been lucky so far that this wear point is still fairly tight. 

Just a picture of the model, serial and pkg numbers from the frame. As I've said, bought it new in 2002 and never been sorry of the purchase. I coulda bought the older style Landlord with Kawasaki engine for a little more but I opted for foot controls and styling over heavier transaxle. 

While the engine on the bench I took the mats off the footrests to clean up some rust and repaint. This is the 2nd time for repaint on the right footrest. Powder coat orange has bubbled and moisture collected under the mats caused erosion. Those darn christmas tree plugs are odd size; ordered new ones off Amazon that were a little short but think will do the job. Had to finish out with some from higher  ones from the hardware store.  

Remember this paint can buy  @Chris727 ? Does just what I needed and matches well. 

What I didn't show new lower crank seal (that I messed up and had to get a 2nd), exhaust and valve cover gaskets.

Monday, March 22, 2021 I filled the gas tank, cranked the engine (forever it seemed until gas flowed into the carb) and it purrs like a kitten. Replaced the hood and hooked up the headlights and everything works as it should. With all the leaves that have fallen over the winter I am going to leave the gators on the deck to crush 'em as soon as the yard is settled enough to run over.

May 11, 2021  45*F this morning and a cool spring after a very warm startup. Grass is green and growing. So far no leaks and the engine is running nice albeit at a higher max rpm. I've mowed 3 times now but didn't operate it at max rpm not knowing just how fast the engine is turning. I have an older tachometer we used to get readings off the combine shafts but it doesn't work when applied to the top of the Vanguard. Ordered a new knock-off throttle/choke and digital tach off Ebay; will report results

Reflective tape is even supplied with these inexpensive digital tachometers so I cut a small piece and applied to the rotating debris screen

May 23, 2021  time to check the revolutions per minute. I knew top end was set too high when I reinstalled the engine earlier so I’ve been running 3/4 throttle. Top end after warm up today

and 3/4 throttle was a little over 3,000. After adjusting I settled at just under 3,300 rpm.