Doc Sprocket
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Here's a quick little how-to on removing the governor mechanism from a Tecumseh L-head engine. Shown is an H40, which is identical to many others including the H60 I did yesterday. You will notice the PTO shaft has been hacked off. The 5/8" clutch was perma-frozen to the shaft, and the engine is destined for the scrap bin. Right after shooting these pics I stripped the rest of the guts out and trashed it. Saveable parts were used to repair my H60. I didn't shoot many pics when I did the governor removal to my H60, so I decided to use this engine for a how-to before I scrapped it.
Start with the usual- drain off the engine oil into a suitable container and remove the clutch, pulley, CVT or anything else installed on the PTO shaft. Disconnect the springs and linkages between the governor arm and carb. Remove and discard the arm assembly coming off the governor shaft (seen in top right of first pic). This will just leave the shaft stub sticking out of the engine.
http://www.diygokarts.com/vb/attachment.php?attachmentid=18904&stc=1&d=1329775346
Next, remove all 8 engine side cover bolts. Laying the engine on the recoil is the best bet here. There's still going to be some oil in the 'case, and (this is one thing I really like about these engines) the entire governor assembly is mounted to the side cover. Once you have removed the cover, you can set the engine aside and not have to touch it again until reinstallation. Gently work the cover loose with a soft-faced mallet, and begin to pull straight off. Cocking the cover sideways may cause it to jam. Do not just start shoving screwdrivers in there to pry it off either. You do not want to damage anything. http://www.diygokarts.com/vb/attachment.php?attachmentid=18905&stc=1&d=1329775708 Here's a shot of the inside of the side cover. At the top you can see where the shaft enters the engine. You can also see the nylon governor gear, and the retainer/oil deflector plate. (more on that later). Go ahead and remove that plate.http://www.diygokarts.com/vb/attachment.php?attachmentid=18906&stc=1&d=1329775854 Great. Grab the nylon gear with your fingers and pull straight off. Now, you encounter the spool, which is retained with a spring clip. You can remove this clip with needlenose pliers, a flathead screwdriver, or whatever you like, and pull the spool and washers off. http://www.diygokarts.com/vb/attachment.php?attachmentid=18908&stc=1&d=1329776071 This leaves you with the shaft and arm assembly. Point it up like in the pic. From outside the case, tap it into the case with a hammer. There is a tiny C-clip there, but it's so much easier to just tap it. It'll pop off. Remove arm from inside the case. Now, all that's left is the governor gear shaft. You can leave this if you like, I opted to remove it. Partially because I make my own gaskets and removing it makes it easy to lay the cover down flat on a sheet of gasket material and trace it out. Should you choose to remove it, here's what you need to know. It's a steel shaft, press fit into the aluminum cover. Grasp the shaft with vise grips and go get your torch. Heat the boss with the torch for about 10 seconds, and twist out the shaft. DO NOT rock or wiggle it, twist it- or risk breaking the aluminum cover. Now- I just did this on two engines with complete success. http://www.diygokarts.com/vb/attachment.php?attachmentid=18909&stc=1&d=1329776399
Now- back to that retainer plate/oil diverter. We don't need the retainer, but the other side of the plate looks like it might deflect oil. Instead of throwing it away and risking the unknown, I chose to cut off the retainer portion, and put the rest back on. I used a grinder, you can use snips too. http://www.diygokarts.com/vb/attachment.php?attachmentid=18911&stc=1&d=1329776960 You may notice I also drilled and tapped a 1/4"-18 NPT hole in the cover for a pulse-pump takeoff and installed a brass hose fitting. If you do this, be sure to thoroughly clean the cover to remove all traces of debris before proceeding. Next, use a small self-tapping screw or other method to seal up the governor shaft hole in the cover. Gently scrape all the old gasket remnants off the mating surfaces of both the cover and engine block. Purchase or make a new side cover gasket and place it over the dowel pins on the block. Apply a light coat of assembly grease on the cam and crank bearing surfaces and lower the cover in place. Work it down gently, again avoiding cocking it on an angle. Having cleaned the bolts apply a drop or two of Loctite #242 blue threadlocker to each bolt. Run them in finger tight and then torque them down in a criss-cross pattern to 9.5 Lbs/Ft. Poof- you're done! All that's left is to fab up a new throttle linkage!
Start with the usual- drain off the engine oil into a suitable container and remove the clutch, pulley, CVT or anything else installed on the PTO shaft. Disconnect the springs and linkages between the governor arm and carb. Remove and discard the arm assembly coming off the governor shaft (seen in top right of first pic). This will just leave the shaft stub sticking out of the engine.
http://www.diygokarts.com/vb/attachment.php?attachmentid=18904&stc=1&d=1329775346
Next, remove all 8 engine side cover bolts. Laying the engine on the recoil is the best bet here. There's still going to be some oil in the 'case, and (this is one thing I really like about these engines) the entire governor assembly is mounted to the side cover. Once you have removed the cover, you can set the engine aside and not have to touch it again until reinstallation. Gently work the cover loose with a soft-faced mallet, and begin to pull straight off. Cocking the cover sideways may cause it to jam. Do not just start shoving screwdrivers in there to pry it off either. You do not want to damage anything. http://www.diygokarts.com/vb/attachment.php?attachmentid=18905&stc=1&d=1329775708 Here's a shot of the inside of the side cover. At the top you can see where the shaft enters the engine. You can also see the nylon governor gear, and the retainer/oil deflector plate. (more on that later). Go ahead and remove that plate.http://www.diygokarts.com/vb/attachment.php?attachmentid=18906&stc=1&d=1329775854 Great. Grab the nylon gear with your fingers and pull straight off. Now, you encounter the spool, which is retained with a spring clip. You can remove this clip with needlenose pliers, a flathead screwdriver, or whatever you like, and pull the spool and washers off. http://www.diygokarts.com/vb/attachment.php?attachmentid=18908&stc=1&d=1329776071 This leaves you with the shaft and arm assembly. Point it up like in the pic. From outside the case, tap it into the case with a hammer. There is a tiny C-clip there, but it's so much easier to just tap it. It'll pop off. Remove arm from inside the case. Now, all that's left is the governor gear shaft. You can leave this if you like, I opted to remove it. Partially because I make my own gaskets and removing it makes it easy to lay the cover down flat on a sheet of gasket material and trace it out. Should you choose to remove it, here's what you need to know. It's a steel shaft, press fit into the aluminum cover. Grasp the shaft with vise grips and go get your torch. Heat the boss with the torch for about 10 seconds, and twist out the shaft. DO NOT rock or wiggle it, twist it- or risk breaking the aluminum cover. Now- I just did this on two engines with complete success. http://www.diygokarts.com/vb/attachment.php?attachmentid=18909&stc=1&d=1329776399
Now- back to that retainer plate/oil diverter. We don't need the retainer, but the other side of the plate looks like it might deflect oil. Instead of throwing it away and risking the unknown, I chose to cut off the retainer portion, and put the rest back on. I used a grinder, you can use snips too. http://www.diygokarts.com/vb/attachment.php?attachmentid=18911&stc=1&d=1329776960 You may notice I also drilled and tapped a 1/4"-18 NPT hole in the cover for a pulse-pump takeoff and installed a brass hose fitting. If you do this, be sure to thoroughly clean the cover to remove all traces of debris before proceeding. Next, use a small self-tapping screw or other method to seal up the governor shaft hole in the cover. Gently scrape all the old gasket remnants off the mating surfaces of both the cover and engine block. Purchase or make a new side cover gasket and place it over the dowel pins on the block. Apply a light coat of assembly grease on the cam and crank bearing surfaces and lower the cover in place. Work it down gently, again avoiding cocking it on an angle. Having cleaned the bolts apply a drop or two of Loctite #242 blue threadlocker to each bolt. Run them in finger tight and then torque them down in a criss-cross pattern to 9.5 Lbs/Ft. Poof- you're done! All that's left is to fab up a new throttle linkage!
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