Yanmar B3-6 overheating

[jimg]

I'm embarrassed to say I cannot find the radiator cap on my gray market mini. The "overflow" tank is fine, but I need to check the coolant level in the radiator. I have a VIO-30 manual that describes there being one, but not where it might be. My radiator is under the right side skin, but I see no filler (or drain for that matter). The fins look clean. The radiator is "tiered" to fit in the confined space. Or maybe there is n oiler cooler sandwiched onto the water that makes it look weird. The VIO-30 claims to not have a oil radiator.

 

[Vetech63]

Some applications of equipment I have seen don't have a cap on the radiator itself, the recovery tank cap IS the radiator/pressure cap. Is your cap a rated pressurized cap?

 

[jimg]

Found the radiator cap cleverly hidden under a rubber flap at the fuel filler. Tank is full, so maybe the thermostat is stuck closed. No leaks visible, fan belt is good. I'll check radiator for dust a little harder. I ran the engine for about 30 minutes at idle and it did fine. Maybe all the rocks are stressing it.

 

[Vetech63]

Sounds like you may have an airflow problem. You should see about a 30-35 degree drop in temperature from the top of the radiator to the bottom. I have seen many engines overheat to lack of a thermostat too (pushes the coolant through the radiator too fast.)

 

[rondig]

Im not sure about b3.. but on my 430 i had to bleed the air out of the system with a little air screw at the top rad hose area. Make sure belt is not slipping. And rad is clear.

 

[jimg]

It appears it's not actually overheating. I was running it today glancing at the gauge every minute or so, and the gauge suddenly shot up, and the fuel gauge did too. I waited about four hours, and it was still showing max.
Maybe a bad ground to the dashboard or something?