Adding this as a public service announcement to help the many people that have this issue, I have gone through it and learned some "gotchas".
The biggest / simplest "gotcha" I learned is how to purge air from antifreeze:
Once you have very good water flow out of the exhaust you may still have overheating.
- A small air pocket in the antifreeze can drive you nuts. You can't see it but it will not allow the antifreeze to circulate properly.
- On the top of the manifold, across from the "radiator cap" is a vent. It takes a 7/16" wrench to remove.
- Top off your AF when cold. Remove this vent plug, pour AF into the cap until it comes out the vent.
- Plug the vent, add an ounce or two more, top off until the overflow cannister is at the low mark (when cold)
- I ran the generator for a few minutes with the cap open and witnessed a few more air bubbles make their way out
- Don't run for too long with the cap off, the system needs to be pressurized to ~12psi to properly cool
If you still have flow and are overheating, it may be the thermostat. Most places say the 73_E uses a 195 degree thermostat. Some say it uses 160 degrees. Currently, I don' have overheating with the 195 but if I do, the next move is to go to the 160 degree thermostat.
If you don't have good water flow:
- Of course check your strainers and impellor
- The impellor is easy to change and make sure you get all broken pieces out!
- For me, the water pump is a sherwood GP-8001.
- To remove the impellor, us a 7/16" socket to pull the 4 stainless bolts out. Impellor kit is "08000K-SHW"
- If the impellor is new and you still do not have a good flow, touch the starter, make sure the impellor moves
- If the impellor does not move, pull the pump off (you may have to remove the hoses, I did not)
- Remove the pump housing, this requires a hex wrench, there are two bolts, top and bottom
- There is a rubber coupling that goes from the pump to the drive shaft. Make sure yours is in good condition.
- For me, this coupling was broken, it was tough to get the pieces out but I replaced with part # 359448
Other things I have learned:
- This generator has alot of safety shut offs. They kill the fuel pump.
- The fuel pump is on the bottom right, if you can't start, crack open the fitting on the copper tubing that runs to the carb to make sure you have plenty of pressure / fuel.
- Apparently there's an "anti diesel" shut off as well. If the system does not detect gasoline (such as water or diesel) it will not energize the fuel pump. I have not seen this in action.
- One last thing, don't be afraid to do a compression test. My cylinders were ~195psi which is very good.
The biggest / simplest "gotcha" I learned is how to purge air from antifreeze:
Once you have very good water flow out of the exhaust you may still have overheating.
- A small air pocket in the antifreeze can drive you nuts. You can't see it but it will not allow the antifreeze to circulate properly.
- On the top of the manifold, across from the "radiator cap" is a vent. It takes a 7/16" wrench to remove.
- Top off your AF when cold. Remove this vent plug, pour AF into the cap until it comes out the vent.
- Plug the vent, add an ounce or two more, top off until the overflow cannister is at the low mark (when cold)
- I ran the generator for a few minutes with the cap open and witnessed a few more air bubbles make their way out
- Don't run for too long with the cap off, the system needs to be pressurized to ~12psi to properly cool
If you still have flow and are overheating, it may be the thermostat. Most places say the 73_E uses a 195 degree thermostat. Some say it uses 160 degrees. Currently, I don' have overheating with the 195 but if I do, the next move is to go to the 160 degree thermostat.
If you don't have good water flow:
- Of course check your strainers and impellor
- The impellor is easy to change and make sure you get all broken pieces out!
- For me, the water pump is a sherwood GP-8001.
- To remove the impellor, us a 7/16" socket to pull the 4 stainless bolts out. Impellor kit is "08000K-SHW"
- If the impellor is new and you still do not have a good flow, touch the starter, make sure the impellor moves
- If the impellor does not move, pull the pump off (you may have to remove the hoses, I did not)
- Remove the pump housing, this requires a hex wrench, there are two bolts, top and bottom
- There is a rubber coupling that goes from the pump to the drive shaft. Make sure yours is in good condition.
- For me, this coupling was broken, it was tough to get the pieces out but I replaced with part # 359448
Other things I have learned:
- This generator has alot of safety shut offs. They kill the fuel pump.
- The fuel pump is on the bottom right, if you can't start, crack open the fitting on the copper tubing that runs to the carb to make sure you have plenty of pressure / fuel.
- Apparently there's an "anti diesel" shut off as well. If the system does not detect gasoline (such as water or diesel) it will not energize the fuel pump. I have not seen this in action.
- One last thing, don't be afraid to do a compression test. My cylinders were ~195psi which is very good.