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Hello, I just picked up what I thought was a really good deal from Craigslist. It’s a Craftsman Professional PGT9000 with a Briggs 28hp engine and a 54” deck. I got it for $200. The add said the engine didn’t run, but when I got to the guys house, he said he replaced a fuse and got it to start and run. I thought I was getting a heck of a deal! I drove it on to my trailer and brought it home. When I got home, I started it up and began backing it off my trailer, then the engine died with a bang. I tried to start it but no luck. I pushed it over to the garage and pulled the spark plugs and found that neither piston was moving. So I removed the engine and opened it up. Both connecting rods were blown apart! I started taking things apart when I found a big gash in the bottom of one of the cylinders and a small one in the other. The cam shaft is also slightly bent. Is this engine repairable, or should it trash it and try to find a new engine?

P.S. I’m not mad at the guy who sold it to me. He said he got it from a guy who owed him money and didn’t know anything about it. I also bought it knowing the engine could be blown.
 

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Looks like a chunk of the lower cylinder wall is gone, so that greatly reduces the likelihood of it being good (it may still work ok).
 

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Discussion Starter #8
I pushed the piston all the way to the bottom of the cylinder and traced the missing area. I’m starting to think that it will still work. I will need new connecting rods, piston rings and cam shaft. I imagine I will also need some gaskets when putting it back together. I’ve never done this, so hopefully I don’t screw it up!
 

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If you can get the parts cheap enough then there's not much to lose by giving it a shot, and it'll be good experience.

OTOH if a good engine appeared at a reasonable price you could swap it in, then play with the carcass of the old one at your leisure.
 

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Discussion Starter #10
If you can get the parts cheap enough then there's not much to lose by giving it a shot, and it'll be good experience.

OTOH if a good engine appeared at a reasonable price you could swap it in, then play with the carcass of the old one at your leisure.
Looks like Ebay is a good place to find engine parts. I’m going to get on the computer tonight and see if I can get All of the parts ordered.
 

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Just me, but since you have no experience with rebuilding an engine, I would look for a decent running used on. A lot of damage in that one and there may be more than you are seeing.
If you want to rebuild an engine and get some experience, start with something that is just worn out and not damaged.....
 

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That engine was probably running on one cylinder when pieces of the already-broken piston made contact with the good one as you backed it off the trailer.

Best and cheapest route is to look for another Vtwin with similar electrical connections. Horsepower rating won't matter much; 16-28 will spin the deck and run the hydro no problem.
 

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That engine was probably running on one cylinder when pieces of the already-broken piston made contact with the good one as you backed it off the trailer.

Best and cheapest route is to look for another Vtwin with similar electrical connections. Horsepower rating won't matter much; 16-28 will spin the deck and run the hydro no problem.
I was thinking the same thing. It wasn’t running smooth while it was running. Oh well.

I think I will start looking for a good used engine.
 

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Just me, but since you have no experience with rebuilding an engine, I would look for a decent running used on. A lot of damage in that one and there may be more than you are seeing.
If you want to rebuild an engine and get some experience, start with something that is just worn out and not damaged.....
AMEN:tango_face_wink:
 

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Stick a fork into it, that block is done unless you want to band aid it and sell the tractor as is. That is assuming the crankshaft is salvageable. I wouldn't do it, I have to sleep at night. FYI the replacement engine is a 49M877-1046, shortblock number 797510 but the tractor may not be worth putting that much money into.
 

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Stick a fork into it, that block is done unless you want to band aid it and sell the tractor as is. That is assuming the crankshaft is salvageable. I wouldn't do it, I have to sleep at night. FYI the replacement engine is a 49M877-1046, shortblock number 797510 but the tractor may not be worth putting that much money into.
don't throw good money after bad, Find a good used engine and make the blown one a project take your time and get it running use it for a backup, I have the same engine sitting on my bench the compression relief cam let loose and i put it back together without it, the engine has a distinct knock so i am pondering on whether or not to save it.
 

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Discussion Starter #19
Is this engine rebuildable?

NO, not practical.

Walt Conner
Ok, thanks for the info everyone. I guess I’ll keep looking for a new mower and keep an eye out for a suitable engine. I think I’ll try to sell the body and try to recoup some of my money.
 

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If I got the image in my mind correctly, the missing bit of the cylinder is so small that it is below the area where the piston has side thrust, below the ring contact area, and basically covers a good chunk of the piston surface area.
Always the optimist, I would honestly consider putting some new or used rods into it, of course checking the rest of the block and sump castings. A new or used cam, and governor assembly if damaged. If the pistons are undamaged, I would pop for new rings unless you do a ring end-gap measurement showing they are within tolerance, and are undamaged. They stayed in the bore, so should have no other problems.
I did not see a pic of the crank rod journals, but most can be cleaned with acid(read up before doing any cleaning as it is dangerous, high ventilation required) and polished to a suitable finish. IOW, with some cleanup and a cam & couple rods & gasketry, you can put it back together.
The two elder statesmen indicate it is burnt toast, and I have no disagreement, but don't have enough imagery to make that call. If you want to play, and don't mind the possibility it won't turn out perfectly, why not? If you don't have experience engine building, this is a perfect candidate to learn on.
If you search the site, you may find several posts where cylinder walls in V-twins have taken a hit, were PBT with some new/used parts, and the story turned out well. If you are an engineer, you might consider how pistons were made in the past vs how they are made now. Big full-skirt was the older design, newer are 'slipper' pistons with just about zero skirt. They (new) depend on a much smaller surface area for side thrust, with two 'fingers' that take the place of the full skirt. Your damage appears to be below the thrust area. IMO. Worth exactly what you pay. Actually, when you showed the penny for size comparison purposes, I though it was minor damage. Maybe I missed something. More pics? Show the rod journals and the sump 'bosses'(cam & governor), and the lifters - are they damaged? Is there other areas where bits'n'pieces were whanged against the sump/block?
tom
 
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