Air compressor motor cutting out at high pressure

[38racing]

With it still at low pressure can you manually move throttle to idle and see if it dies.

[ericconn]

Thanks, everyone. This was happening in warmer weather in the summer, so when things are spoken of being "frozen", is that a temperature thing or a mechanically stuck kind of thing? Either way, I will probably try to take it to a shop if I can't figure it out, but it's helpful to give them some info about what it might be, so thanks for the info so far.

[ericconn]

With it still at low pressure can you manually move throttle to idle and see if it dies.

In general, it's really hard to keep this thing running once it's started. I have to get the throttle and choke into a sweet spot. Again, I rebuilt the carb, and will get a new spark plug this weekend.

[madmantrapper]

Sounds like you still have carb trouble to me. I'd try cleaning once more.

[KE4AVB]

Thanks, everyone. This was happening in warmer weather in the summer, so when things are spoken of being "frozen", is that a temperature thing or a mechanically stuck kind of thing? Either way, I will probably try to take it to a shop if I can't figure it out, but it's helpful to give them some info about what it might be, so thanks for the info so far.

If it is Summer where you are and we are thinking of the colder weather here in the USA where it is Winter then it was water vapor freezing in the control air solenoid we were thinking of here. We have been going though a rather cold spell around here at last few weeks.

[ericconn]

I got a new spark plug and ordered a whole new carburetor today that I hope will arrive before this weekend when the temperature is supposed to be in the 50's (I'm in Virginia).

The motor is actually a GX140, the tank is an Emglo, and the pump is a Emglo KU, I believe my unit is one of these: http://www.mastertoolrepair.com/emglo-parts-k5hga-17p-k5ga-17p-k5wga-17p-k5cga-17p-p-1999.html. It seems there are several companies that sell parts for these compressors, which is nice.

Is this the bypass valve: http://www.mastertoolrepair.com/airline-throttle-control-honda-04-65-hp-tcsp-5565-p-545.html? I'm sure I'll be able to figure out what it is on the actual pump, I just haven't looked for it yet. I'm going to try to take a look at it tomorrow, so if anyone knows what I should look for to diagnosis a frozen bypass valve, and where to get a new one if it isn't in that parts diagram, I would appreciate any advice.

Thanks again.

[KE4AVB]

I got a new spark plug and ordered a whole new carburetor today that I hope will arrive before this weekend when the temperature is supposed to be in the 50's (I'm in Virginia).

The motor is actually a GX140, the tank is an Emglo, and the pump is a Emglo KU, I believe my unit is one of these: http://www.mastertoolrepair.com/emglo-parts-k5hga-17p-k5ga-17p-k5wga-17p-k5cga-17p-p-1999.html. It seems there are several companies that sell parts for these compressors, which is nice.

Is this the bypass valve: http://www.mastertoolrepair.com/airline-throttle-control-honda-04-65-hp-tcsp-5565-p-545.html? I'm sure I'll be able to figure out what it is on the actual pump, I just haven't looked for it yet. I'm going to try to take a look at it tomorrow, so if anyone knows what I should look for to diagnosis a frozen bypass valve, and where to get a new one if it isn't in that parts diagram, I would appreciate any advice.

Thanks again.

Providing this is your setup then:

That would be the throttle control. The valve that controls its is the Pilot Valve RCB-M-HU-125. This is an air version of an electric pressure switch that would be use on an electric motor driven compressor. As the tank reaches the desired max pressure it sends air pressure to operate the throttle control valve by applying pressure to throttle down (idle) the engine.

The pilot valve is probably the one that maybe sticking; although, the throttle control could be. You can check for pressure in between them when the tank is full and the engine should be to idling. No pressure at this time would indicate that pilot valve is bad. If the pressure it is good then check the throttle valve for movement if little or no movement then it is bad but check for binding linkages to rule them out.

[ericconn]

Providing this is your setup then:

That would be the throttle control. The valve that controls its is the Pilot Valve RCB-M-HU-125. This is an air version of an electric pressure switch that would be use on an electric motor driven compressor. As the tank reaches the desired max pressure it sends air pressure to operate the throttle control valve by applying pressure to throttle down (idle) the engine.

The pilot valve is probably the one that maybe sticking; although, the throttle control could be. You can check for pressure in between them when the tank is full and the engine should be to idling. No pressure at this time would indicate that pilot valve is bad. If the pressure it is good then check the throttle valve for movement if little or no movement then it is bad but check for binding linkages to rule them out.

Thanks. I will install the new carb and make sure it wasn't just that, but at least I'll know what to replace if it's something else. If I get it up and running, I'll probably also replace the valves in the pump. I'll update when I know, might not be til consistently warm weather. Many thanks, again.

[ericconn]

I was able to get outside and work on the compressor this weekend. The new carb didn't end up working; the fuel line intake came out at the wrong angle, so the hose couldn't be hooked up to it. I replaced the parts on the old one with the new one's, and cleaned out the body of the old one as best I could. Got it to fire up but couldn't get it to stay running.

I got the engine to start enough times that it put some air in the tank. One odd thing I noticed was that if I used the pilot valve to manually release air, the throttle control thing, first photo seen below (which I can't find on a parts diagram), shoots out. Is this normal? Also, what is the name of that part? Thanks. Also, my model is definitely a K5HGA-17P.

Can't get photos to load as images, here are the links.
http://wecphoto.smugmug.com/photos/i-ndcjbDT/0/L/i-ndcjbDT-L.jpg

Pilot valve:
http://wecphoto.smugmug.com/photos/i-nvKzMpR/0/L/i-nvKzMpR-L.jpg

[StarTech]

The reason your pictures would not load here is that they are 800 x 600 and the site limits 600 x 600. They would need to be resized to be within these limits.