G5200H hard start, some coolant overflow, odd smell exhaust on start up.

JackKo · Mar 23, 2021

G5200H help request!
1. Hard to start replaced battery, alternator charging.
2. slight coolant overflow,
3. slight odd smell exhaust on start up.
4. Water pump had slight leak.
5. Replaced water pump, thermostat,
6. Replaced radiator cap.
7. Wondered if starter was having problems but I think I better rethink this.

I have used this mower for 20 years.
Last year hard to start) thought battery was bad, new battery, still hard to start.
I had noticed previous years a little coolant from overflow tube,replaced cap, still a little coolant leak from tube, i blamed it on mowing angle hill.
After I get it started “with a car battery” it seems to run OK.
**Do I have a combustion to coolant leak?**
Im guessing when I shut up the mower I have coolant leaking into the combustion chamber adding compression and causing hard to start?
How do I diagnose it?
Can I fix it?
I have average mechanical skills, torque wrenches, compression tester,

There is No longer a Kubota dealer here in Cedar Rapids, Iowa and it taints my enjoyment of owning a my orange tractor.

Roadworthy · Mar 23, 2021

The hard starting could be simply a glow plug failure after all these years. Check the voltage at the glow plugs when energized. There could be a dropping resistor in line not allowing them to get voltage, too. I wouldn't worry about coolant from the overflow though coolant into the engine is another story. What color is the exhaust when you first start the engine? How long does it stay that color? A small amount of white or gray smoke is normal. It should stop within a couple minutes as the engine warms. Black smoke indicates too rich mixture frequently caused by blockage in air intake or dirty air filter.

denchen · Mar 23, 2021

Start the motor and let it settle. Make sure the coolant is filled to the top and is overflowing then watch the filler neck. If bubbles come out and keep coming, its a good chance the head gasket is leaking.