This engine should have a low oil shut-down system, You will see a clump of wire's/connectors near the stop switch. Separate them then unplug the yellow wire, This should disable the system to see if the engine now continues to run. If it does, Then the low oil system can be tested to find the faulty part.

 

RestroRob,

I know if anyone knows the answer it'll be you.. so i'll give that a shot and let you know what happens.


thanks

 

I have been having a lot of problems just like this. What I have been having problems with is AR RMV pumps. You hook up the water hose and turn on the water and it flows just fine. Almost as soon as you start the engine the water flow will stop and the back pressure stalls out the engine. AR knows there is a problem as we have now replaced over 2 dozen pumps under warranty. Not saying this is your problem but it could be a pump problem.

 

Hey Fixer67,

Can you tell me any troubleshooting steps in checking the AR pump on this unit..?

That could potentially be the issue, and I would pretty much be screwed; if the pump's bad.. its worth scrap minus the engine!

Should i change the oil in the pump, it was a little over the recommended 1/2" on the stick!

Also, when i check the oil on the pump.. Do i unscrew it, wipe off.. and re-insert it all the way and tighten it back to check, or do i just let it set even without tightening it??

 

Does this problem exist when water is off? I had a trash pump doing same thing but you could loosen or remove gas cap it would run replaced cap problem solved.Also if the pressure unloader valve is not working properly it possibly could stall engine.

 

Does this problem exist when water is off? I had a trash pump doing same thing but you could loosen or remove gas cap it would run replaced cap problem solved.Also if the pressure unloader valve is not working properly it possibly could stall engine.

Its only when the unit is connected to the water supply and turned on.

She cranks up like a champ, then dies pretty much within 10-15 secs.

 

This engine should have a low oil shut-down system, You will see a clump of wire's/connectors near the stop switch. Separate them then unplug the yellow wire, This should disable the system to see if the engine now continues to run. If it does, Then the low oil system can be tested to find the faulty part.

Hey RESTROROB,

It's starting right up every single time, BUT it has to be on choke to start up..
ANY THOUGHTS??

It's the ghost in the machine !!! haha

 

Is the engine dying while washing or trigger released while pressure regulator should be unloading?
Posted via Mobile Device

 

it has to be on choke to start up..

Most all engines have to be on choke to start up !?!?

Screw the dipstick in to check oil level, Change the oil with non detergent 30 weight engine oil......

The AR pumps fixer is talking about is the cheap homeowner crap, They don't make this RMV model to fit your GX390 so you have the better pump that likely isn't causing your issue.....

 

I went and got some SAE30 non-detergent oil, i'm gonna drain the old stuff..
put in the new (18.45oz) and i'll see if it makes a difference.

 

I changed the pump's oil, removed the low oil wire from the engine and still nothing...

any other suggestions ???

a friend of mine said to troubleshoot it by removing the pump and try starting the engine alone to isolate whether its the pump or the engine causing the issue(s)..

im sure its a stupid question but i'll ask anyway: Do i have to drain the pumps oil before removing it from the engine or is it sealed ? I just don't want a bigger mess all over the floor than i've got already.

 

If regulator/unloader is not working properly it will kill the engine. I have the same pump/motor set up.
Posted via Mobile Device

 

My brush mower acts crazy Ill chech theoil shut off and look for othe suggestions

 

You can slide the pump off without draining the oil, Some have a hole or slot in the pump where the crankshaft meets the pump. There could be a allen set screw holding the pump shaft to the crankshaft.

I've replaced many bad unloaders and have five pressure washers in my rental fleet, I've never seen a bad unloader shut down a 13hp Honda at full throttle 3600 rpm (that's where they should be ran at) in 5-10 seconds run time.

This is the steps I give customers that rent;

Hook up both hoses and turn water on wide open.

Pull trigger on wand until all air is purged from the pump and a steady stream of water sprays out.

Turn switch on and give full choke.

Continue to pull trigger to release pressure on pump for easier starting then start the engine, Let the engine warm up a half minute before releasing the trigger.

Do not leave the trigger out more than a minute or two at a time, Doing so will only prematurely wear the unloader out and cause the pump to run warmer than normal.

Now,

Are you getting garden hose water pressure through the pump and out the end of the wand ?

Are you getting full pump pressure while holding the wand trigger open soon as you start the engine ?

Does the engine die while the wand trigger is pulled and putting out high pressure water ?

Just for giggles you can bypass the whole ignition kill system switch and all by disconnecting the black wire that goes from the wire bundle up under the gas tank.....

 

NEVER START UP A PRESSURE WASHER WITHOUT WATER GOING THOUGH IT. YOU WILL DESTROY THE PUMP IN LESS THAN 30 SECONDS. Water cools and lubs the pump. The inside of a pump can reach 700*F in less than a minute with no water in it. To test the unit first hook up the garden hose and turn the water on but leave the high pressure hose off. Just point the out put in a safe direction. Start the pump up. The AR pumps that are giving me some many problems will stop pumping any water at all even with the out put hose removed and the back pressure stills the pump. The AR pumps in question have a check valve problem.The jam under pressure and will not let any water past. A simple thing to do is just remove the pump and just get the engine running as a stand alone unit. If the engine runs without the pump then that should tell you something.

 

You can slide the pump off without draining the oil, Some have a hole or slot in the pump where the crankshaft meets the pump. There could be a allen set screw holding the pump shaft to the crankshaft.

I've replaced many bad unloaders and have five pressure washers in my rental fleet, I've never seen a bad unloader shut down a 13hp Honda at full throttle 3600 rpm (that's where they should be ran at) in 5-10 seconds run time.

This is the steps I give customers that rent;

Hook up both hoses and turn water on wide open.

Pull trigger on wand until all air is purged from the pump and a steady stream of water sprays out.

Turn switch on and give full choke.

Continue to pull trigger to release pressure on pump for easier starting then start the engine, Let the engine warm up a half minute before releasing the trigger.

Do not leave the trigger out more than a minute or two at a time, Doing so will only prematurely wear the unloader out and cause the pump to run warmer than normal.

Now,

Are you getting garden hose water pressure through the pump and out the end of the wand ?

Are you getting full pump pressure while holding the wand trigger open soon as you start the engine ?

Does the engine die while the wand trigger is pulled and putting out high pressure water ?

Just for giggles you can bypass the whole ignition kill system switch and all by disconnecting the black wire that goes from the wire bundle up under the gas tank.....

RESTROROB,

I just went out and tried your start-up method you mentioned above..
- water hose supply fully turned on attached to unit
- held down spray gun while trying to start
- full choke & full throttle
- it started up on 1st pull as usual and ran a little longer with pressure coming through gun as it should
it did run with full pressure for about 1 minute, engine stopped and i choked it again to start: it ran about 15-30 secs and died again.. and engine backfired after it died out..

then i tried to start it again and the recoil rope broke so i'll fix it... and by the time i check back on here, maybe you can give some insight ..

Thanks
~J

 

J,

Your fired !!! 1:11 till now to replace a rope..... . :laugh:

Have you replaced the spark plug ?

IMO, I believe you have a engine problem over a pump problem.....

Can you feather the choke on/off and keep it running ?

A in-line spark tester sure would be handy to find out if it's either ignition or carb related.....

Was this a brand new out of the box carb you installed ?

 

When you cleaned the fuel tank, did you unscrew the fuel filter from the tank and clean it?
Was there alot of rust in the tank ?
If you remove the fuelline from the carb, does the fuel flow or trickle?
While checking the fuel flow, loosen the fuel cap and see if the flow increases.

4 hours and 50 minutes is a long time to replace a rope.

 

J,

Your fired !!! 1:11 till now to replace a rope..... . :laugh:

Have you replaced the spark plug ?

IMO, I believe you have a engine problem over a pump problem.....

Can you feather the choke on/off and keep it running ?

A in-line spark tester sure would be handy to find out if it's either ignition or carb related.....

Was this a brand new out of the box carb you installed ?

__________________________________

HAHAHAH.. LoL

Sorry it took me so long to reply, wifey's High School reunion last night kept me up later than expected so my apologies.

Good news !!! -- Got the recoil rope changed.

______

Its got a brand new spark plug.
The carburetor is a new one (not OEM) but aftermarket replacement for the GX390 series.

I've got an inline spark tester, i'll check it later today.. and i'll also try to
"feather the choke" .. and see if we can isolate the problem after that.

Thanks again RESTROROB.

 

when you cleaned the fuel tank, did you unscrew the fuel filter from the tank and clean it?
Was there alot of rust in the tank ?
If you remove the fuelline from the carb, does the fuel flow or trickle?
While checking the fuel flow, loosen the fuel cap and see if the flow increases.

4 hours and 50 minutes is a long time to replace a rope.

________

sorry man.

My bad!

 

death in family .. hold'n off w/ posting for now.
thanks for all yalls help.

Very appreciative!!!


-J

 

will it stay running if you pull the trigger on the wand
maby the previous owner cranked up the unloader valve to the pump
and the motor cant handle the higher pressure

 

I know this is a very old thread but google keeps using it to answer this question so I will post my info for when somebody else has this problem. My GX390 electric start pump would start fine and run about 2 minutes before starting to sputter and then die. We replaced carb, gas cap, spark plug, disconnected low oil shutoff all with no improvement. This is a newer model engine that has 3 wires coming from the coil, a yellow (low oil shutoff), and a red and black which are + and - from the coil and form a loop for the coil primary circuit. When we connected the red and black wires into each other it ran fine. Forever. Our problem was an intermittent short in the ignition switch that was interrupting the coil primary circuit. For whatever reason the short only developed after the engine ran 2-3 minutes. Every small engine I've ever worked on had a grounding wire to kill the coil, but this one interrupts continuity on the coil circuit.

 

Did you replace the ignition switch?

 

Hi captain Crabgrass,

I have a Honda GX390 it’s about 10 years old it’s well maintained and just this year it cuts out when hot then starts up again and runs for 20 / 25 minutes but each time I did it the run time gets shorter. Now it won’t even start I have installed a brand new genuine Honda carburetor with all me gaskets and insulator new fuel filter new spark plug cleaned up the flywheel and ignition coil and reset it. It now will only fire with easy start sprayed into air intake housing. I disconnect the wiring today to check the ignition coil as a process of lamination plugged the red and black together and turned the engine and had a strong spark did the same with the yellow. Checked the ignition for resistance and got some different readings! Going to plug the black and red tomorrow as a by pass and see if it will start. I believe the switch is the problem as there are two wires the older switch had one wire with a grounding wire this is a new type of switch it has some electronics inside that are intermittent. Have new switch coming tomorrow will report back on success.