002a Runs Great then Dies

[Chainbreaker]

When I open up the louvers, I begin to think about air flow. So, the large fan on the main shaft blows into the area where my new "close when run" shroud. From there, is the air flow to go across the fins of the "head" (from right to left - from front) then out the louvers? If this is the case, I have no air flow and I can't "see" from left to right across the fins of the "heads". (I'm saying "heads", the items between the louvers and the close-to-run shroud.) See image when open the louvers.
View attachment 751376

Yes, air should pass from one side to the other and exit out through the louvered shutters. You should be able to feel significant air flowing out the shutters after they have opened up when running. You should also be able to see some daylight between the "Cylinders" in the middle where the two cylinders are connected as well as space between the cylinder fins on the outer most edges as well (left & right). I'm fairly sure there is also some limited airspace between the "Cylinder Heads" on top where they meet in the middle. Wherever there is a pronounced fin sticking out, it should have a way to dissipate that heat via some airflow.

If you are looking from the "Louvered Shutter" side You will need to have the "Close To Run" cover open to allow light through in order to see through. Easier to see though the cylinder fins from the "Close To Run" side with the cover up. If you were to inspect the cylinder fins at night you could put a flashlight on the opposite side to see if light is coming through in those finned cylinder airflow areas.

Your cylinder fins do appear quite rusted, can't tell from the photo's if they are rusted up solid. Though it is not unusual for the fins to be coated in some rust and will work Ok as long as they are not rusted solid (flaking thick rust). If you have a solid piece of wire or rod, you could probe all those areas to see if it will pass through and perhaps knock off some rust while you probe.

 

[n5yzv]

Yeah, I think they are pretty caked up. I had the close to run door open, and was looking through on a bright sunny day. I saw very little light. I also noticed there was little air passing through the other day when I was doing the test. Sounds like I need to get an elbow on the exhaust, then look into getting the fins clear up. I may look into removing whatever is covering them so I can make sure to get it cleaned up, then put some rust converter on them. I think some Phosphoric acid and a spay hose might work, but unsure. Thoughts?

 

[Chainbreaker]

I would start out by wire probing using something stiff say around 1/8" diameter through the fins and see how many are open, or can force out some rust and open up channels. Then you might consider using something like a pistol cleaning rod with wire brush tip or bore snake to work through the fins to see what you can scrub loose. On one pass you might try using some type of rust remover, sparingly, to see if that helps the process. Not sure about using a rust converter...that might make the rust more permanent but could potentially help to halt future rust as long as it doesn't turn into a tight coating that inhibits the transfer of heat to air. You might also try power washing through the fin openings. However, I would be very careful where you aim the tip as some power washers can do damage to wires, gaskets, etc. or force in water where it doesn't belong.

Then if all else fails... there is "the fix" which would be to take the heads and cylinders off and have them sandblasted/glass beaded and then paint them with a high temp header paint to inhibit any future rusting. Since you are in Boerne, TX (pronounced "Bernie" if memory serves me right) you are not having to deal with much humidity or coastal air so once the rust is off you should be good to go for a very long time!

 

[glcaines]

You might also try dry ice blasting in place since it leave no residue. However, I've never used it to blast rust, but it works great on some other stuff.

 

[justacitizen]

if the overtemp switch has been to hot several times it might be weak. get a new one and blow the fins out real good with compressed air and also check the flywheel to make sur the fan fins on it aren't broken off or something. make sure all of the duct work is in place. i have an old DJB onan that has the same basic engine as the 002a and it doesn't have the louvers.

 

[Guyfang]

if the overtemp switch has been to hot several times it might be weak. get a new one and blow the fins out real good with compressed air and also check the flywheel to make sur the fan fins on it aren't broken off or something. make sure all of the duct work is in place. i have an old DJB onan that has the same basic engine as the 002a and it doesn't have the louvers.

You still do not even know if the over temp is shutting the set down. First test, the you can decide what to do. Assuming will..................................
Do I really need to finish the sentence?

 

[Dock Rocker]

Assuming will..................................
Do I really need to finish the sentence?

Cause many hours of entertainment for the more seasoned among the group!



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[Farmitall]

Cause many hours of entertainment for the more seasoned among the group!



Sent from my iPhone using Tapatalk

Ya, but we all love it!!

 

[justacitizen]

You still do not even know if the over temp is shutting the set down. First test, the you can decide what to do. Assuming will..................................
Do I really need to finish the sentence?

sorry i thought the switch had been tested many pages ago.