Hi guys, so I’m in a pickle with this mower and I’ve hit the top end of my expertise. Hoping you can shed some light.
I got an old buntin 36 walk behind for my very steep hilly property and it’s been running fine all summer. Usually starts second pull. During a recent mow it conked out on me. I narrowed it down to a fuel issue and because the carbs for these are cheap and have decent reviews I bought a new one for simplicity sake. After I mounted it it started up fine. Issue is the new carb had an engine breather input, but there was already one between the carb and air filter so i figured it wasn’t necessary and decided to just plug it since the old carb seemed to have a brass plug in that spot from the factory anyway. For some reason this created a vacuum or something and stopped the needle from seating. The carb flooded to the point the engine hydro locked when I went to start it. I gave it a couple of hard pulls as it was filling before it completely locked since I didn’t know what was going on and I think I messed up the timing or something. After fiddling with it a few times while sorting out the carb issue the engine will not kick over at all anymore.
Now that the background is covered here’s where I’m at. I have spark, air, and fuel. Starter fluid directly in the chamber does nothing. I’ve let it dry out for a few days with the spark plug out and still gotten nothing. For compression I’ve got 50 psi. I saw another post here where someone said 75 is the minimum for these. When I open the little window behind the carb the valves seem to be actuating ok. Should I pull the head? What should I look for with the valves and how would I adjust them? How can I check the timing and what do I do if it’s off? This is all very frustrating as this was the last now of the season and I’ve got a little strip of grass in the front of my lawn taunting me. Pretty close to just buying a new (used since I can’t find them new) motor, but I only paid 200 for the whole mower and that’s less than these motors go for haha.
I got an old buntin 36 walk behind for my very steep hilly property and it’s been running fine all summer. Usually starts second pull. During a recent mow it conked out on me. I narrowed it down to a fuel issue and because the carbs for these are cheap and have decent reviews I bought a new one for simplicity sake. After I mounted it it started up fine. Issue is the new carb had an engine breather input, but there was already one between the carb and air filter so i figured it wasn’t necessary and decided to just plug it since the old carb seemed to have a brass plug in that spot from the factory anyway. For some reason this created a vacuum or something and stopped the needle from seating. The carb flooded to the point the engine hydro locked when I went to start it. I gave it a couple of hard pulls as it was filling before it completely locked since I didn’t know what was going on and I think I messed up the timing or something. After fiddling with it a few times while sorting out the carb issue the engine will not kick over at all anymore.
Now that the background is covered here’s where I’m at. I have spark, air, and fuel. Starter fluid directly in the chamber does nothing. I’ve let it dry out for a few days with the spark plug out and still gotten nothing. For compression I’ve got 50 psi. I saw another post here where someone said 75 is the minimum for these. When I open the little window behind the carb the valves seem to be actuating ok. Should I pull the head? What should I look for with the valves and how would I adjust them? How can I check the timing and what do I do if it’s off? This is all very frustrating as this was the last now of the season and I’ve got a little strip of grass in the front of my lawn taunting me. Pretty close to just buying a new (used since I can’t find them new) motor, but I only paid 200 for the whole mower and that’s less than these motors go for haha.