honda generator engine not running very hot?

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So I have a Honda 6500 watt generator with the Honda gx390 engine on it. I Was surprised that if it doesn't have much load on it the engine really doesn't get warmed up much at all. I ran it for about 30 minutes when it was 50 degrees outside and I hit it with temp gauge and it was only about 105 degress on the cylinder head. I shut it off and it did take me about 5 minutes to find the infrared temp gauge. Not sure how much it would cool down in that period though.
 
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I was taught years ago (still true?) that diesels need to be loaded up for a minimal period each time they are run...not much different than a car engine.
 
Originally Posted By: 69GTX
I was taught years ago (still true?) that diesels need to be loaded up for a minimal period each time they are run...not much different than a car engine.


Yes it's still true. I don't believe it's as important on gas engines though. They don't carbon up and wet stack like diesels do. I was using mine to run power tools so it's only under load when I'm using a tool. I'll have to run it for 10 minutes or so next time under a good load to build up some heat.
 
Put a resistive load on your generator when you test run it, like a space heater.
 
Originally Posted By: motor_oil_madman
So I have a Honda 6500 watt generator with the Honda gx390 engine on it. I Was surprised that if it doesn't have much load on it the engine really doesn't get warmed up much at all. I ran it for about 30 minutes when it was 50 degrees outside and I hit it with temp gauge and it was only about 105 degress on the cylinder head. I shut it off and it did take me about 5 minutes to find the infrared temp gauge. Not sure how much it would cool down in that period though.


Keep in mind that the infrared, non contact, thermometer is only accurate on a black body. It's wildly inaccurate on reflective surfaces. Put your finger on the fins. I'd guess you can't keep it there.
 
^^^ I'm doubting the 105F too. I've owned two inverter generators. at no load they basically tut-tut at around 2,200 rpm, doing less than the 6500 mentioned. If it's 30F out they don't get very warm, but I'd guess they sit at 140F judging by hand.
 
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Originally Posted By: Cujet
Originally Posted By: motor_oil_madman
So I have a Honda 6500 watt generator with the Honda gx390 engine on it. I Was surprised that if it doesn't have much load on it the engine really doesn't get warmed up much at all. I ran it for about 30 minutes when it was 50 degrees outside and I hit it with temp gauge and it was only about 105 degress on the cylinder head. I shut it off and it did take me about 5 minutes to find the infrared temp gauge. Not sure how much it would cool down in that period though.


Keep in mind that the infrared, non contact, thermometer is only accurate on a black body. It's wildly inaccurate on reflective surfaces. Put your finger on the fins. I'd guess you can't keep it there.


I aimed it on the valve cover, the sump, and the cylinder head. They were all about 105-120 degrees if I remember right. Also I put my hand on these areas cause I didn't believe it either and they felt about like 105 degrees. Didn't burn my hand. The engine must have cooled off a bunch in the 5 minutes or so it took me to find the infrared thermometer. It's a fluke meter, not some cheap meter.

Then I've run it other times where it had more of a load and would have burned my hand big time. I think it's the continuous load that creates the heat. I was just surprised at how cool it runs without a continuous load.
 
Originally Posted By: eljefino
Put a resistive load on your generator when you test run it, like a space heater.


I use it to run power tools. I use to go night fishing with it frequently to run lights and two space heaters. lol The space heaters worked ok if you sat in between them.
 
I used a 4500 watt 240V heater to load my old 5kW Winco generator. A conventional 1500W home space heater on 1/2 power is the load for my 1200W Honda and it takes 30 minutes or more to get good and hot. I would run your under load until it got to 160°F or higher.
 
Originally Posted By: motor_oil_madman
Originally Posted By: Cujet
Originally Posted By: motor_oil_madman
So I have a Honda 6500 watt generator with the Honda gx390 engine on it. I Was surprised that if it doesn't have much load on it the engine really doesn't get warmed up much at all. I ran it for about 30 minutes when it was 50 degrees outside and I hit it with temp gauge and it was only about 105 degress on the cylinder head. I shut it off and it did take me about 5 minutes to find the infrared temp gauge. Not sure how much it would cool down in that period though.


Keep in mind that the infrared, non contact, thermometer is only accurate on a black body. It's wildly inaccurate on reflective surfaces. Put your finger on the fins. I'd guess you can't keep it there.


I aimed it on the valve cover, the sump, and the cylinder head. They were all about 105-120 degrees if I remember right. Also I put my hand on these areas cause I didn't believe it either and they felt about like 105 degrees. Didn't burn my hand. The engine must have cooled off a bunch in the 5 minutes or so it took me to find the infrared thermometer. It's a fluke meter, not some cheap meter.

Then I've run it other times where it had more of a load and would have burned my hand big time. I think it's the continuous load that creates the heat. I was just surprised at how cool it runs without a continuous load.


impressive... if you put your hand on it then I'm much more believing. still pretty head-shaking to think that's all it climbed to.
 
Originally Posted By: meep
impressive... if you put your hand on it then I'm much more believing. still pretty head-shaking to think that's all it climbed to.


Well the cooling fins have to allow for full load at the highest ambient temperature anticipated for operation, so at low or no-load it's not going to have much of a problem rejecting the heat, right?
 
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