Yes, if you look just behind the throttle arm that comes out of the crankcase you will see a nipple for the other end of the big tube coming out of the crankcase, kind of up high under the black plastic top cord real assembly. You are correct, its the crankcase vent designed to reburn the positive crankcase fumes by routing them back into the airbox - reducing emissions. What actually prompted this rebuild was excessive oil coming out of the crankcase through this tube, basically it is blow by from the cylinder rings not sealing properly. I routed the hose into a beer can (catch can) until I got around to fixing it (this video).
Hi, I have the same exact engine I picked up at the landfill. It runs but blows a lot of white smoke. I was thinking on trying to replace the piston rings (never done before) in the hopes of salvaging the engine. Did you need to use a piston ring compressor to reinsert the piston? Did you have to hone the piston bore (never done before)? Any tips before I proceed? Thanks.
I just replaced the rings, I didn't bother honing the bore, just a new set of rings I ordered from the internet. Yes I used a regular piston ring compressor from O'Reillys, nothing fancy, it is a must though. Clean everything really well with brake cleaner so you don't have any grit, make sure you get the rings aligned per Toro and lube up the ring compressor and piston really well. I would also recommend checking the valve clearance on the valves, pretty simple but will make a huge difference in performance if they are out of alignment (they probably are). Also make sure you pull the carb apart and clean it out really well with some carb cleaner. Toss a little in line fuel filter on the fuel line as well to keep crap out of the carb.
@@GX470PracticalMaintenance So I finally got everything back together and started up the mower for the first time yesterday. It started fine but it seems to run a little rough. In particular, it almost sounds like a go-kart. I tried adjusting the idle screw on the carburetor but that didn’t help. Some other symptoms include a number of kickbacks when starting the engine and backfires when I stop the mower. My thinking is the timing is off because maybe when I reinstalled the camshaft I didn’t align the teeth exactly to the crankshaft (even though I marked it before removing). Does this sound like a timing issue to you or something else? I’m not sure how to exactly know the position of the camshaft when installing it back in the housing. How did you handle this step? BTW, I replaced rings, hone cylinder, adjusted valves, removed and cleaned carburetor. The good news is the engine is not smoking like it used to.
@@SteveSmith-nh6ms It could be that the timing is off. Here is a link to the manual, check out page 46. www.kohlerengines.com/engines/onlinecatalog/pdf/14_690_01_EN.pdf Its been a while, but I believe the marks are little triangles. Line up the Large yellow cam gear with the camshaft. If that is all set then I would check your valve lash to make sure they are tight and at the correct gapping.
great Vid.; Q: where does the large tube go from the back of the air box to engine? Is it a crank case vent or ??
Yes, if you look just behind the throttle arm that comes out of the crankcase you will see a nipple for the other end of the big tube coming out of the crankcase, kind of up high under the black plastic top cord real assembly. You are correct, its the crankcase vent designed to reburn the positive crankcase fumes by routing them back into the airbox - reducing emissions. What actually prompted this rebuild was excessive oil coming out of the crankcase through this tube, basically it is blow by from the cylinder rings not sealing properly. I routed the hose into a beer can (catch can) until I got around to fixing it (this video).
@@GX470PracticalMaintenance Much Gratitude !+
does any one know the torque that the bolts are supposed to be tightened at?
Guttentight
Hi, I have the same exact engine I picked up at the landfill. It runs but blows a lot of white smoke. I was thinking on trying to replace the piston rings (never done before) in the hopes of salvaging the engine. Did you need to use a piston ring compressor to reinsert the piston? Did you have to hone the piston bore (never done before)? Any tips before I proceed? Thanks.
I just replaced the rings, I didn't bother honing the bore, just a new set of rings I ordered from the internet. Yes I used a regular piston ring compressor from O'Reillys, nothing fancy, it is a must though. Clean everything really well with brake cleaner so you don't have any grit, make sure you get the rings aligned per Toro and lube up the ring compressor and piston really well. I would also recommend checking the valve clearance on the valves, pretty simple but will make a huge difference in performance if they are out of alignment (they probably are). Also make sure you pull the carb apart and clean it out really well with some carb cleaner. Toss a little in line fuel filter on the fuel line as well to keep crap out of the carb.
@@GX470PracticalMaintenance
So I finally got everything back together and started up the mower for the first time yesterday. It started fine but it seems to run a little rough. In particular, it almost sounds like a go-kart. I tried adjusting the idle screw on the carburetor but that didn’t help. Some other symptoms include a number of kickbacks when starting the engine and backfires when I stop the mower. My thinking is the timing is off because maybe when I reinstalled the camshaft I didn’t align the teeth exactly to the crankshaft (even though I marked it before removing). Does this sound like a timing issue to you or something else? I’m not sure how to exactly know the position of the camshaft when installing it back in the housing. How did you handle this step? BTW, I replaced rings, hone cylinder, adjusted valves, removed and cleaned carburetor. The good news is the engine is not smoking like it used to.
@@SteveSmith-nh6ms It could be that the timing is off. Here is a link to the manual, check out page 46. www.kohlerengines.com/engines/onlinecatalog/pdf/14_690_01_EN.pdf
Its been a while, but I believe the marks are little triangles. Line up the Large yellow cam gear with the camshaft. If that is all set then I would check your valve lash to make sure they are tight and at the correct gapping.