Lawnmower engine issue

**M R Dux** · 03-18-2016, 08:58 AM

Anybody know anything about a 21 HP Briggs Vanguard 2 cylinder engine? My Troy-Built mower has one. A couple of years ago it started missing and lugging down under load, sometimes when I initially engage the PTO. I took it to a local mechanic a while back and he said it was carburetor. He rebuilt the carb and hit me for several $$. Later that year it started doing the same thing. I can pull the spark plugs and one of them will be covered with carbon but dry. Most times I can change that plug and it will run fine for a while.When it is missing out, it blows black smoke--not bad but noticeable.

I have ran regular gas, not the non-ethanol stuff, in it and have added Stabil and occasionally Seafoam to the gas. Each year I replace the fuel filter when I change the oil. I'm at a point that this is getting to me, having to deal with this most every time I use it. The mower is around 18 years old and has given me flawless service up until the time this started. It only takes me 45 minutes to mow my whole yard so it doesn't have nearly as many hours on it as most 18 year old mowers would. I might have to add oil to it once during the mowing season. Replacing it is not an option now.

I'm going to replace all of the fuel line from the tank to the carb with a new filter, change air cleaner, already put new plugs in last night. Any ideas?

**Cray** · 03-18-2016, 09:26 AM

Probably weak coil on that one cylinder. If I'm not mistake it has a separate coil for each cylinder.

**M R Dux** · 03-18-2016, 01:03 PM

Originally Posted by cray

Probably weak coil on that one cylinder. If I'm not mistake it has a separate coil for each cylinder.

Thanks Cray. I took a long lunch and ran home to tear into it. When I got the plastic cowling off the engine, it was apparent the flywheel was solid rust. I pulled that coil, cleaned the flywheel with coarse sandpaper, then replaced the coil after setting the gap. Started up and ran like a champ.Tried every way to get it to bog down and it wouldn't. At least if it starts acting up again now I know where to start.

**Cray** · 03-18-2016, 01:16 PM

Originally Posted by mrdux

Thanks Cray. I took a long lunch and ran home to tear into it. When I got the plastic cowling off the engine, it was apparent the flywheel was solid rust. I pulled that coil, cleaned the flywheel with coarse sandpaper, then replaced the coil after setting the gap. Started up and ran like a champ.Tried every way to get it to bog down and it wouldn't. At least if it starts acting up again now I know where to start.

Good deal. Doubt you have anymore trouble.

**Lawnmowerman43** · 03-18-2016, 01:49 PM

If it ever does it again take both of the CDI packs off and sand the posts that they attach to, those two post and the bolts are the only ground that you have to make the magic work

**M R Dux** · 03-18-2016, 02:45 PM

Hey, who said crappie fishing was expensive? I just saved enough $$ to buy something I have absolutely no need for. Got a garage full already.

BTW, that 18 year old lawn tractor mower has 245.6 hours on it.Hopefully it will be the last one I ever buy. Paying somebody to mow my yard was looking more attractive than buying a new ZTR.

**Lawnmowerman43** · 03-18-2016, 03:23 PM

Originally Posted by mrdux

Hey, who said crappie fishing was expensive? I just saved enough $$ to buy something I have absolutely no need for. Got a garage full already.

BTW, that 18 year old lawn tractor mower has 245.6 hours on it.Hopefully it will be the last one I ever buy. Paying somebody to mow my yard was looking more attractive than buying a new ZTR.

How many hours on your boat motor? 245 for 18 years on your lawnmower says you ain't mowing grass

**M R Dux** · 03-18-2016, 04:40 PM

Originally Posted by Lawnmowerman43

How many hours on your boat motor? 245 for 18 years on your lawnmower says you ain't mowing grass

If the factory installed hour meter is correct.

I probably put less than 300 hours on my 75 Yamaha in the almost 20 years I owned it. That's the nice thing about living so close to a lake that has an abundance of ramps. No telling how many hours I put on my Terrova 80 in the 4 years I owned it. Lots of days my outboard was ran 10 minutes or less in 6-8 hours fishing.

**RetiredRR** · 03-19-2016, 09:22 PM

I'd like to know the brand of that zero turn mower. My 10 year old Gravely is still going strong with the 25 hp Kawasaki. I just finished mowing 2 acres and am glad I have the 52"
cut.

**gone fission** · 03-29-2016, 09:03 AM

Might wanna check the valve clearance wonna these days too, is fairly easy on Briggs.

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