ERP air compressor model AS40P - running issue

[Jon Powell]

I have an AS40P from ERP with a Honda GX390 engine and Chinook K30 air pump. When running the engine will stall after a few minutes. When going to restart it I noticed it pulled the choke closed. This seems to happen everytime it stalls. Ran it again but holding the choke lever in the open position so it wouldn't pull shut. This time a backfire was noticeable just before the engine stopped. Not a fuel issue. Not a loss of ignition. Removed the belt and the engine runs fine. Replaced the belt and left valves open on compressor and tank, so not charging tank engine continues to run fine. Any suggestions what it causing the engine to stall as the pressure builds in the tank?

 

[carbon]

What pressure does it get to? Does the unloader valve open and start to dump air? Also welcome to the forum

 

[Jon Powell]

Hi. Thanks for the welcome. No the onloader doesn't sound like it's doing anything. The first time it stalls it reaches 5.5 bar. On 3 attempts i can get it to reach 7 bar. Have just noticed also that after it stalls air is venting from the filler/crankcase breather on the air pump. Broken ring on one of the pistons???

 

[Jon Powell]

Tried a 4th time. Got to to 8 bar and now unloader working. Engine continuing to run. Faltered abit but continued.

 

[Jon Powell]

Wondering if it's just suffering from insufficent use. Managed to continuously run and repeatedly unload for 5 minutes.

 

[carbon]

Drain all the air from the tank and check the non return valve, it should screwed into the tank on the end of the pipe from the pump. Not that familiar with engine driven but there should be something to stop compressed air returning to the pump. Air that's returning to the pump would probably escape past piston rings without there necessarily being any damage

 

[Jon Powell]

Thanks. Will do so and have a look.