[deentaylor]

Went out to cut the grass this afternoon and after about three minutes the machine erupted with the kind of clattering noise that made me instantly want to hit the PTO and shut everything down. My first thought was that it was something with the deck/belts, but those seemed clear. When I tried to restart, the flywheel on the 20HP B&S Vanguard V-Twin spins, but it doesn't sound like it's turning anything. Dipstick shows low-ish oil, but not empty.

It sounds pretty much like this:

Is there anything relatively simple that could have happened, or is it likely to be a busted cam, and therefore not worth fixing?

I only paid $300 for this machine and I've gotten nine years of use out of it, but still....

 

[PA318Guy]

Remove both spark plugs and put a dowel rod or something down the spark plug hole and turn it over by hand to see if the pistons are still moving.

 

[Rarefish383]

Sounds like the bendix is not kicking out.

 

[Rarefish383]

well watching further, the bendix is engaging.

 

[ST1100A]

I've seen many of them break connecting rods or the bearing cap wore oblong from low oil, then it would break. I'd open up the crankcase and find a broken rod.

 

[joneill4]

I'm pretty sure PA318Guy nailed it. I'd have a consolation beer within arms reach when I ran this test, because I do not think you are going to like the results. If you do happen to have two pistons that move up and down, pull the valve covers and see if all four rockers are moving. This possibility is doubtful, since most valve problems will result in the valve staying shut.

 

[deentaylor]

Thanks for the perspective, guys. I tried PA318's test this morning. As you all guessed, nothing is moving behind the spark plugs when I manually turn the flywheel; the values are shut tight. (It's too early for consolation beer, sadly!)

Getting this Vanguard 20HP 351777 repaired is likely to involve significant shop labor and expensive parts, correct? It is worth investing significantly in a 23-year-old tractor, or should I be shopping for somewhat newer used tractor instead?

 

[PA318Guy]

A new replacement engine is going to set you back $1,000 - $1,500, so if you can fix it for less than that might be worth it if the rest of the machine is in excellent shape.

 

[deentaylor]

Thanks, PA318 -- that's really helpful. I'll get an estimate/diagnosis from my local shop.

 

[deentaylor]

Seems like my Sabre 2048HV is, in fact, a goner.

When I explained my situation to the owner at my local shop and asked about the prospects for rebuilding/replacing the engine his exact words were "I wouldn't put a nickel into that machine." He went on to say that they've been having a really hard time sourcing parts or replacement engines, so even if I wanted to spend the money he wasn't sure how long it would be before I was back in the seat. In other words, RIP Sabre.

Which brings up the question of what to do next. I do know another small engine mechanic who I think is more willing to work with used parts cannibalized from other machines, so I could seek a second opinion.

Or I could start shopping. I would like to stick with a garden tractor. In addition to cutting grass, I used the Sabre for snow removal (with a 42-inch BM19414 blade) and hauling wood chips and logs and other things around the property in a trailer.

Since I already have the blade/wheel weights/chains, one approach would be to look for a compatible GT series machine. On the other hand, replacing the dead tractor with another almost 20-year-old machine, seems kinda risky. Would it be better to step up for something that's only 10-12 years old -- featuring with a hydraulic lift and power steering -- like an X700, even though it would mean sourcing a different model blade (or blower)?

What do you think -- where is the "sweet spot" in the used garden tractor market in 2022?

 

[MARK (LI)]

Look around for a used tractor with a blown trans and see if you can salvage the engine from that and switch it

 

[biker3777]

The BS is famous for dislodging the valv guides,but I never heard of one dislodging both

 

[ST1100A]

The BS is famous for dislodging the valv guides,but I never heard of one dislodging both

Main thing that caused the valve guides to back out of the heads was the head overheating. People never removed the blower housing and cleaned off the grass and debris build-up in the cooling fins and little air passageways, causing them to overheat, then the guides pulled out of the heads.
Once the guides moved out, the rocker would hit it and usually either break the rocker arm or bend the pushrod.
Briggs came out with an improved cylinder head because of that problem.

 

[Jim16]

"Would it be better to step up for something that's only 10-12 years old -- featuring with a hydraulic lift and power steering -- like an X700"

O.K. We all know where this is going. Let's just cut right to it.... 😁

 

[deentaylor]

I can't imagine what you're talking about...