[Doug Musick]

I have a 20kw Kohler generator head on a Yanmar engine.  It has glow plugs.

It cranks fine in warmer weather but below 40 it takes several hits on the starter switch to turn over.  It fires up right away once the starter cranks even down to 25 degrees so far.  It seems like a weak starter.

However, it got me to thinking has anyone installed an engine block heater on their Yanmar?  Even though I have glow plugs and they seem to be working I think being able to preheat the engine should reduce wear and tear.  What are your thought

We plan to regularly use the Newell in cold weather, even with temps in single digits.

[bestgenman]

I think you will find your Yanmar has an intake manifold heating element rather than glow plugs.  Yanmars, except for a few smaller models, are direct injection rather than indirect injection such as Kubota engines.

There are coolant heaters available that utilize the 1” npt plug on the exhaust manifold side of the engine .  Most are 400w 120v and do an excellent job keeping the coolant warm.

I can’t address your starter issue, not enough information posted.

[Richard]

Hmmmmm. You might want to check the voltage at the starter while cranking. 25 yr old coach could have bad connections, including the ground.

[Doug Musick]

Got the Fluke out. Voltage on the starter post was 13.6 V static. When the starter switch engaged it would drop. Hard to read as it was fluctuating alot, but mostly in the 12 and 11 volt range and one instance of 10 something. It dropped more when starter was spinning than when it was just hitting but not turning.


It was about 20 last night. The gen started on the first try. I let it run for about 20 minutes to warm completely. Then shut off and tried starting several times to get the V readings. On a couple of those tries the starter would hit but not spin.

[Richard]

could be that the starter is due for rebuild. Brush or armature problems would explain hit or miss spinning and your voltagwe observations. Sounds like the solenoid is pulling in, but the starter motor is not spinning. Is that right? Then occasionally the starter motor will spin.

On the occasions where the motor doesn't spin, does a love tap with a hammer cause it to turn over? Showing my age here, too many years of living with raggedy automobiles.