CubCadet_Chris
Member
- Joined
- Jul 2, 2019
- Threads
- 6
- Messages
- 37
I have a Cub Cadet model 1515 lawn tractor my neighbor gave me that he got tired of messing with after it wouldn't start anymore. When he gave it to me all it needed was a new starter and battery and it fired right up! This tractor has a 15hp Kohler Command CV436 single piston engine. Once I knew it would run I changed the oil and filter, spark plug (gapped to spec), fuel filter, air filter.
After I've been using it to mow my yard, I've been noticing after about 15-20mins of runtime the engine would bog down under load where it almost stalls out, but never actually dies (yet...). It only does this when the PTO is engaged. When it starts to bog down I do 1 of 2 things:
A. let off the throttle and let it catch itself
B. disengage the PTO and let it catch itself
I cut the grass at least once a week so its not like the grass is getting too tall for the mower.
I was leaning towards a fueling problem. So I pulled the carburetor apart and cleaned it. It didn't look dirty at all when I cleaned it. That did not fix the issue. I adjusted the idle speed knob to give it a little more fueling but the only impact that had was adjusting the low idle speed. The other adjustment on the carb had a lock cap on it from the factory so I left it a lone and I don't think its truly a carb issue after seeing a nice full bowl of fuel and how clean it was. I also noticed the fuel line was dry rotted so I pulled the gas tank out and replaced the line. That had no impact either. I have not touched the fuel pump or ignition coil yet. But I doubt its a fuel pump because the carb seems to be getting fuel. My neighbor said he has replaced the ignition coil in the last year or two. I haven't ruled these out yet, but seems unlikely to me.
Then I noticed it seems like the engine is running hot. I say this because if I pull off the 2 side panels on each side of the engine it runs fine under load. So it seems like its not getting enough air flow. I have check the intake screen and shroud and all is clear. I even hosed down the engine to clean it up and make sure there is no debris anywhere. I have made sure the oil level is correct and its at the full mark. I put 2 quarts of 10W-30 in when I changed it.
The only other thought I have is that the muffler seems to have a leak and maybe its letting too much hot air into the engine compartment heating the engine even more. Even if it wasn't leaking its kindof a bad design in my opinion because the outlet faces the front of the tractor and there are air inlets up front under the headlights so its basically just blowing hot air in its own path.
When searching online it seems in general all various types of Kohler engines run into this problem (mostly twin cylinder) and I never see a solution. I'm trying to logically trace the problem without throwing all the parts at it. Does anybody know common problems with this engine related from this symptom and what to try next?
I can post some pics later if that helps so you can see the condition its in.
After I've been using it to mow my yard, I've been noticing after about 15-20mins of runtime the engine would bog down under load where it almost stalls out, but never actually dies (yet...). It only does this when the PTO is engaged. When it starts to bog down I do 1 of 2 things:
A. let off the throttle and let it catch itself
B. disengage the PTO and let it catch itself
I cut the grass at least once a week so its not like the grass is getting too tall for the mower.
I was leaning towards a fueling problem. So I pulled the carburetor apart and cleaned it. It didn't look dirty at all when I cleaned it. That did not fix the issue. I adjusted the idle speed knob to give it a little more fueling but the only impact that had was adjusting the low idle speed. The other adjustment on the carb had a lock cap on it from the factory so I left it a lone and I don't think its truly a carb issue after seeing a nice full bowl of fuel and how clean it was. I also noticed the fuel line was dry rotted so I pulled the gas tank out and replaced the line. That had no impact either. I have not touched the fuel pump or ignition coil yet. But I doubt its a fuel pump because the carb seems to be getting fuel. My neighbor said he has replaced the ignition coil in the last year or two. I haven't ruled these out yet, but seems unlikely to me.
Then I noticed it seems like the engine is running hot. I say this because if I pull off the 2 side panels on each side of the engine it runs fine under load. So it seems like its not getting enough air flow. I have check the intake screen and shroud and all is clear. I even hosed down the engine to clean it up and make sure there is no debris anywhere. I have made sure the oil level is correct and its at the full mark. I put 2 quarts of 10W-30 in when I changed it.
The only other thought I have is that the muffler seems to have a leak and maybe its letting too much hot air into the engine compartment heating the engine even more. Even if it wasn't leaking its kindof a bad design in my opinion because the outlet faces the front of the tractor and there are air inlets up front under the headlights so its basically just blowing hot air in its own path.
When searching online it seems in general all various types of Kohler engines run into this problem (mostly twin cylinder) and I never see a solution. I'm trying to logically trace the problem without throwing all the parts at it. Does anybody know common problems with this engine related from this symptom and what to try next?
I can post some pics later if that helps so you can see the condition its in.