I have a honda gx390 motor with a 4200PSI AAA(?) 4gpm pump. Both pump and motor are still under warranty but I wanted to see if this was something I could simply fix or not. When the machine is on and the trigger on the gun is pulled it sounds like it is running fine. However when I let go of the trigger it runs nice but with a big spike in RPMs (?) about every 5 to 7 seconds. It just happens for one second and then it does it again every 5 to 7 seconds. I changed the carburetor and air filter thinking that might be it but no luck. Today I hooked up a PSI gauge between my pump and DS injector and noticed that when the engine spikes its going up to around 4000PSI and then it slowly drops to around 1500PSI before it spikes again 7 seconds later, getting back around 4000PSI for only a second. When I pull the trigger i am only getting around 1000PSI. I messed with the unloader a little bit to see if it would snap out of it but it didn’t work. It still works fine for soft washing and it seems as though I am still getting around 4GPM but just with no high pressure option. Is this cheap pump on its way out? The only thing that confuses me is that I’m still getting around 4GPM. I feel like if the pump was shot I wouldnt get that? I am not that mechanically inclined but I try to be a do-it-yourselfer as much as I can. help?
. If u put the white or yellow tip on do you get pressure?
My first thought is abad unloader.
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Video or it didn’t happen.
