Hello all! New here, and sorry but this will be a long post.
Long story short, the engine is toast and it's getting a new one, pending delivery on Tuesday. Part operator error, part seller ignorance. Probably mostly operator error.
Let's start at the beginning. About a year and a half ago I picked up a 1967 Simplicity Broadmoor 707 from an old gent. He's an old Italian guy in his 70's and was the second owner of the machine. It's been repainted for sure, but I'm not sure what else was done. First owner passed away in the early 90's and gave it to the old Italian, but he didn't use it as he had 4 other mowers/tractors. I picked it up off him for $400 with mower deck, 36" snow blower attachment, a dozer/plow blade, and tire chains. When I picked it up, he started it up and drove it around his driveway to show it was in good working order. It did and didn't smoke, so I was satisfied and I loaded it up and was on my way. Before I left, he mentioned he thought he overfilled the oil. I checked the "dipstick" and saw oil was all the way to the top. I figured it'd either burn off or I'd drain some after I got home.
Fast forward about an hour and a half (how far I had to haul it). I started it, drove it off the trailer, and decided to drive it around and attempt to mow parts of my lawn (I was excited to see how it would cut!). After about 5 minutes, it started shooting out blue smoke. I thought it was the excess oil burning off and kept going. Eventually shut off and wouldn't start again, so I pulled her into my shop and tried to figure out what was wrong. Turns out the piston seized. I checked the oil and there was none! I sat there trying to figure out how it lost that much oil in 5 minutes, because it couldn't have all burned off in that time. Looked at the trailer and there were new oil spots (the trailer had a lot of fluid spots on it). It must've leaked out on the way home and I missed them.
Went through the process of un-seizing the piston carefully, and there was some light scoring (as to be expected) but I've seen worse. The rings looked good and weren't cracked, and there wasn't much I could do to a 50 year old engine anyway and I couldn't find a short block to replace it, so I oiled it and put it back together. Started fine, ran fine, it cut grass fine (never did heavy cutting) so I didn't think much of it. Winter came around and I put the blower on. Chicago winters are hit or miss, usually hit. First few snows of 6" or less were fine. After the snow got wetter and heavier, I noticed it bogged down to the point of dying. Kept running it all winter like that. Something didn't seem right though, so I did a compression test, and turned out it was only pumping out 25PSI! What a champ for hauling an 800lb tractor with my 200lb fat butt through a Chicago winter. Pictures below are of what the cylinder looked like when I took it apart. Anyway, since I still couldn't find a short block, I honed the cylinder and replaced the rings, hoping to regain some compression to keep her going. Turns out I was wrong, as it only made the problem worse. Now it wouldn't start at all. Didn't even sound like it wanted to start.
I decided repowering it was the next best option. The engine model is a 7HP 171701-0120. Best replacement for it is a 10.5HP 215802-0015, and the dimensions aren't an exact fit, but the bolt pattern and shaft size is the same. That engine I found for $600 (plus tax and shipping, adding over $100). I decided to keep looking around. Turns out 215000's replacement was 219907-3029, but that model was discontinued. 219907-3029's replacement is a 21R707-0011, which is still a 10.5 HP and same bolt pattern and shaft size. I ended up ordering that one for $450 shipped as it was cheaper than the 215000 series and it technically should fit like the 215000 series, which was the recommended replacement.
So, I already know it won't be a perfect fit. The bolt pattern is the same, but some of the new engines' overall dimensions are slightly larger (by 1-2 inches). I'm prepared to move/fabricate what's needed. The engine comes with the muffler, but no fuel tank. That's OK because I already have the original fuel tank even though it'll probably need to be moved.
My question: I think it'll be fine, but will the belts/pulleys/trans handle the HP increase alright? Are there any other problems you guys can foresee? Any other advice?
Thanks for reading, and sorry it was such a long post! Morale of the story: check your oil every time you sit on the machine
Long story short, the engine is toast and it's getting a new one, pending delivery on Tuesday. Part operator error, part seller ignorance. Probably mostly operator error.
Let's start at the beginning. About a year and a half ago I picked up a 1967 Simplicity Broadmoor 707 from an old gent. He's an old Italian guy in his 70's and was the second owner of the machine. It's been repainted for sure, but I'm not sure what else was done. First owner passed away in the early 90's and gave it to the old Italian, but he didn't use it as he had 4 other mowers/tractors. I picked it up off him for $400 with mower deck, 36" snow blower attachment, a dozer/plow blade, and tire chains. When I picked it up, he started it up and drove it around his driveway to show it was in good working order. It did and didn't smoke, so I was satisfied and I loaded it up and was on my way. Before I left, he mentioned he thought he overfilled the oil. I checked the "dipstick" and saw oil was all the way to the top. I figured it'd either burn off or I'd drain some after I got home.
Fast forward about an hour and a half (how far I had to haul it). I started it, drove it off the trailer, and decided to drive it around and attempt to mow parts of my lawn (I was excited to see how it would cut!). After about 5 minutes, it started shooting out blue smoke. I thought it was the excess oil burning off and kept going. Eventually shut off and wouldn't start again, so I pulled her into my shop and tried to figure out what was wrong. Turns out the piston seized. I checked the oil and there was none! I sat there trying to figure out how it lost that much oil in 5 minutes, because it couldn't have all burned off in that time. Looked at the trailer and there were new oil spots (the trailer had a lot of fluid spots on it). It must've leaked out on the way home and I missed them.
Went through the process of un-seizing the piston carefully, and there was some light scoring (as to be expected) but I've seen worse. The rings looked good and weren't cracked, and there wasn't much I could do to a 50 year old engine anyway and I couldn't find a short block to replace it, so I oiled it and put it back together. Started fine, ran fine, it cut grass fine (never did heavy cutting) so I didn't think much of it. Winter came around and I put the blower on. Chicago winters are hit or miss, usually hit. First few snows of 6" or less were fine. After the snow got wetter and heavier, I noticed it bogged down to the point of dying. Kept running it all winter like that. Something didn't seem right though, so I did a compression test, and turned out it was only pumping out 25PSI! What a champ for hauling an 800lb tractor with my 200lb fat butt through a Chicago winter. Pictures below are of what the cylinder looked like when I took it apart. Anyway, since I still couldn't find a short block, I honed the cylinder and replaced the rings, hoping to regain some compression to keep her going. Turns out I was wrong, as it only made the problem worse. Now it wouldn't start at all. Didn't even sound like it wanted to start.
I decided repowering it was the next best option. The engine model is a 7HP 171701-0120. Best replacement for it is a 10.5HP 215802-0015, and the dimensions aren't an exact fit, but the bolt pattern and shaft size is the same. That engine I found for $600 (plus tax and shipping, adding over $100). I decided to keep looking around. Turns out 215000's replacement was 219907-3029, but that model was discontinued. 219907-3029's replacement is a 21R707-0011, which is still a 10.5 HP and same bolt pattern and shaft size. I ended up ordering that one for $450 shipped as it was cheaper than the 215000 series and it technically should fit like the 215000 series, which was the recommended replacement.
So, I already know it won't be a perfect fit. The bolt pattern is the same, but some of the new engines' overall dimensions are slightly larger (by 1-2 inches). I'm prepared to move/fabricate what's needed. The engine comes with the muffler, but no fuel tank. That's OK because I already have the original fuel tank even though it'll probably need to be moved.
My question: I think it'll be fine, but will the belts/pulleys/trans handle the HP increase alright? Are there any other problems you guys can foresee? Any other advice?
Thanks for reading, and sorry it was such a long post! Morale of the story: check your oil every time you sit on the machine