Pressure washer engine backfiring

[dawgn86]

Hi All

I bought a new pressure last year from Northern Tool...3000psi with a Honda engine GX160 or 190 engine.

It cranks and runs well, but when I let off the pressure trigger, it backfires many times. I use a quality fuel ( the non ethanol )...

Any ideas of how to cure this?

Thanks

 

[demarpaint]

Check the spark plug, but odds are it probably is in need of a carburetor adjustment. I've had it happen over the years and a carburetor adjustment did the trick. Sometimes the vibration knocks them out of adjustment.

 

[Rand]

does it sound like its under a high load when its doing this?
might be the unloader.

If its not working right its trying to compress water that isnt flowing.

Some of these pumps have a very tiny hole and they get clogged with debris from your hose or water.
(I always flush my hose for a min before hooking up)

If it sounds like it is under no load when its backfiring.. its probably some kind of carb issue.

 

[Donald]

Check for clean cooling fins, mouse nest.

 

[dawgn86]

I got it last summer and used it some...used it a few weeks ago and noticed the backfire...does when when you let off the pressure...hate to think the unloader or carb is out of whack with it being less than a year old. I have a new plug to try and see if that helps.

 

[Kira]

'Twas just going to say that. A mouse nest made my friend's B&S 22HP (lawn tractor) backfire

 

[dawgn86]

So, I fired up the pressure today and used it about a half hour..no backfire at all....maybe the new plug did the trick. I also put in some Start Tron as well.

 

[meep]

running lean will backfire. overheated valves will promote backfire (too tight). sometimes I've seen very efficient engines, when under zero load, spit and pop, as they spin free. you can also try a different fuel. if it's not burning completely, it will ignite when it passes through the muffler

 

[dawgn86]

Thanks...that will be the next thing I try if it returns