Anthony P 5 #1 Posted May 28, 2021 Guys, I was making GREAT progress getting an HH120 on a 1974 Sears SS12 running then something bad happened... Here's the story. This tractor was sitting out in the weather about two years with no carburetor...a rag was stuck in the intake. I cleaned out the gas tank, replaced fuel lines, and installed a (cheap) aftermarket carb. Engine started but ran rough and had no power. I removed the ignition coil and replaced it with Dale's 12V electronic ignition system. Engine started and, after a few adjustments, ran like a scalded dog! The next hurdle was getting the battery to charge...essential with all-electronic ignition. After replacing the ammeter and voltage regulator, the charger was working and I thought I was nearing project completion. I had the engine running at full throttle while checking battery voltage when something bad happened! The engine vibrated, clanked, and shut off. Now it WILL start but something clanks inside the engine and it only runs for a few seconds. Can someone tell me what broke and what I should look for when I open it up? Share this post Link to post Share on other sites
Maxwell-8 4,277 #2 Posted May 28, 2021 STOP running it! You blew the motor. Probably the oil splasher or balnacer broke. Maybe cams? Did you check the oil? 2 Share this post Link to post Share on other sites
Gregor 4,846 #3 Posted May 28, 2021 (edited) You say it will run for a few seconds. If this is true, it is apparently not a major component failure, but there is a clanking noise. This sounds a lot like what happened to my Kawasaki motor. A screw from the butterfly in the carb came out, and was sucked into the cylinder. Made a he!! of a racket, but would run. Don't run it anymore. Pull the head and check the piston. Head gaskets are cheap. My Kawasaki was a vertical shaft motor. I don't know if this would even be possible on a horizontal shaft. Edited May 28, 2021 by Gregor 1 Share this post Link to post Share on other sites
Achto 27,603 #4 Posted May 28, 2021 Hard saying what let loose for sure. As suggested, pull the head and look for damage. If you find nothing there then you will have to take a look inside to see what happened. Maybe a broken skirt on the piston or ?? 2 Share this post Link to post Share on other sites
Anthony P 5 #5 Posted May 28, 2021 9 hours ago, Maxwell-8 said: STOP running it! You blew the motor. Probably the oil splasher or balnacer broke. Maybe cams? Did you check the oil? Thanks. I only tried to restart it...and it did...once after the failure. Oil level is good and no filings on the dipstick. Share this post Link to post Share on other sites
Anthony P 5 #6 Posted May 28, 2021 2 hours ago, Achto said: Hard saying what let loose for sure. As suggested, pull the head and look for damage. If you find nothing there then you will have to take a look inside to see what happened. Maybe a broken skirt on the piston or ?? Thanks. I'll start there... 1 Share this post Link to post Share on other sites
WHX?? 48,828 #7 Posted May 28, 2021 (edited) Sounds like the fellas got you covered so I'll just Please keep us posted on what happened we're always interested in things that can happen. Edited May 28, 2021 by WHX24 2 Share this post Link to post Share on other sites
stevasaurus 22,764 #8 Posted May 28, 2021 The HH-120 was used in Wheel Horse tractors. This is about the engine, not the tractor. The thread is fine here. 1 1 Share this post Link to post Share on other sites
Anthony P 5 #9 Posted June 26, 2021 OK...After checking with local small engine shops, I FINALLY found someone who will rebuild my engine. He wants $475...seems too high to me. Is that a reasonable cost for a rebuild? I have ZERO experience tearing down/rebuilding small engines. If I decide to tackle it myself, can you guys help me out when I hit (inevitable) snags? Thanks for your help so far... Share this post Link to post Share on other sites
Gregor 4,846 #10 Posted June 26, 2021 Did you ever open it up, pull the head? How do you know it needs rebuilt. Machine shop charge for my last engine rebuild was $265. Rebuild kit $120. New bearings, $60. Valve guides, $20. I'd say $475 isn't bad, but you don't know what all he is doing. Rebuilding an engine can mean a LOT of things, or a few things. Share this post Link to post Share on other sites
Anthony P 5 #11 Posted June 26, 2021 5 minutes ago, Gregor said: Did you ever open it up, pull the head? How do you know it needs rebuilt. Machine shop charge for my last engine rebuild was $265. Rebuild kit $120. New bearings, $60. Valve guides, $20. I'd say $475 isn't bad, but you don't know what all he is doing. Rebuilding an engine can mean a LOT of things, or a few things. Valuable feedback Thank you...no, I have not done anything yet. I just know it was running good until it made a racket and quit. Share this post Link to post Share on other sites
Gregor 4,846 #12 Posted June 26, 2021 3 minutes ago, Anthony P said: Valuable feedback Thank you...no, I have not done anything yet. I just know it was running good until it made a racket and quit. Your guy might pull the head, remove a butterfly screw, put the head back on, and charge you $475. Or, he may be as honest as the day is long. Share this post Link to post Share on other sites
Anthony P 5 #13 Posted August 9, 2021 OK...I think I will abandon this project. Reluctant (INEXPERIENCED...) to open up the engine. I found a whole tractor with a good engine for $300..."been sitting for a few years". Flushed the gas tank, put in fresh gas, sprayed a little ether, and IT STARTED RIGHT UP! Thanks guys for the help...we'll never know what broke... Share this post Link to post Share on other sites
WHX?? 48,828 #14 Posted August 9, 2021 Good to hear Anthony but you know what ....you should open up that motor any way now that you have nothing left to lose. It's already broke, inquiring minds what to know what might have happened and best of all a little experience for yourself opening up a crankcase just to see what goes on. On 6/26/2021 at 1:49 PM, Anthony P said: I have ZERO experience tearing down/rebuilding small engines. One step closer to having that experience 1 Share this post Link to post Share on other sites
WheelHorse520H 708 #15 Posted August 9, 2021 On 6/26/2021 at 2:49 PM, Anthony P said: OK...After checking with local small engine shops, I FINALLY found someone who will rebuild my engine. He wants $475...seems too high to me. Is that a reasonable cost for a rebuild? I have ZERO experience tearing down/rebuilding small engines. If I decide to tackle it myself, can you guys help me out when I hit (inevitable) snags? Thanks for your help so far... I had no experience when I did a tear down on my Onan P220 and so far I have not had any major issues, these guys’ll keep you on track. 15 minutes ago, WHX?? said: Good to hear Anthony but you know what ....you should open up that motor any way now that you have nothing left to lose. It's already broke, inquiring minds what to know what might have happened and best of all a little experience for yourself opening up a crankcase just to see what goes on. One step closer to having that experience I agree, it’s already broken, just take it apart and have a look, if you don’t want to keep it sell it for someone to recycle or rebuild themselves. 1 Share this post Link to post Share on other sites
Gregor 4,846 #16 Posted August 9, 2021 No one ever tore down an engine, until their first one. Share this post Link to post Share on other sites
WHX?? 48,828 #17 Posted August 9, 2021 7 minutes ago, WheelHorse520H said: I had no experience when I did a tear down on my Onan P220 and so far I have not had any major issues, these guys’ll keep you on track. I agree, it’s already broken, just take it apart and have a look, if you don’t want to keep it sell it for someone to recycle or rebuild themselves. You tied into a Onan with no experience you is our hero Wheel H 520 Sides Squonky is always lookin for Tecky parts .... you never know what can be salvaged. Share this post Link to post Share on other sites
WheelHorse520H 708 #18 Posted August 9, 2021 (edited) 6 minutes ago, Gregor said: No one ever tore down an engine, until their first one. 5 minutes ago, WHX?? said: You tied into a Onan with no experience you is our hero Wheel H 520 Sides Squonky is always lookin for Tecky parts .... you never know what can be salvaged. @Anthony P You can tear it down, @WHX?? made a good point, if you don’t want to put it back together sell the parts. Maybe even use the money to reposed the tractor. There are some options for you here. Edited August 9, 2021 by WheelHorse520H Share this post Link to post Share on other sites
Anthony P 5 #19 Posted August 10, 2021 All GREAT advice! I will tear it down and have a look just as soon as I get the 3-point hitch transferred over and get this "new" one plowing! I'll post back WHEN I hit a snag... 1 Share this post Link to post Share on other sites
Anthony P 5 #20 Posted August 20, 2021 (edited) Here we GO! OK, I pulled the head. Carbon build up, but nothing really glaring...UNTIL... The intake valve lifted right out of the sleeve...that ain't right is it? Edited August 20, 2021 by Anthony P Add pictures Share this post Link to post Share on other sites
Gregor 4,846 #21 Posted August 20, 2021 Looks like you retainer pin either broke, or came out. I would hope for broke. If it simply came out, then you have to figure out why. Unless this is a common occurrence on the HH120 1 Share this post Link to post Share on other sites
Anthony P 5 #22 Posted August 20, 2021 Busted open the crankcase...nothing seems wrong. No pieces parts in the bottom. Oil looks good... Now I need to know about match marks before I go any further AND to understand what I'm looking at. The little gear up in the right-hand corner does not seem to be attached to anything (held in place by the crankcase cover?) and will easily pull out. What is it? Do I need to put in some match marks before I pull it out for proper timing when I put it back together? Share this post Link to post Share on other sites
Anthony P 5 #23 Posted August 20, 2021 1 hour ago, Gregor said: Looks like you retainer pin either broke, or came out. I would hope for broke. If it simply came out, then you have to figure out why. Unless this is a common occurrence on the HH120 Do I have to take it completely apart to replace the retainer pin? Share this post Link to post Share on other sites
Anthony P 5 #24 Posted August 20, 2021 56 minutes ago, Anthony P said: Do I have to take it completely apart to replace the retainer pin? Pulled the valve cover and answered my own question...shoulda started there... 1 Share this post Link to post Share on other sites
Anthony P 5 #25 Posted August 20, 2021 Mystery solved!!! I know WHAT BROKE! Now wish I had started with the valve cover... Still need to know how to fix it and get it back together though... Share this post Link to post Share on other sites
