I hate small engines. Help diagnostic?

212cc northern tool pressure washer. 

Was running great. Then would do the rpm hunt and cut off like it was running out of fuel after about 10 minutes. 

Fought and fought woth it, added seafoam and fresher gas. Time down to 2-3 minutes. 

Cleaned carb and reinstalled. Now, just hard cut out, not fuel starve hunt. 

Replaced carb, fuel lines, air filter. 

10 minutes, down to 3 just like before. 

Wait a few seconds, fires right up. More you fight it or rush it, you have to add choke. Like it's running out of fuel. 

What the everloving berkeley am I missing? 

Small engines, in my experience, are sensitive to the plugs being fouled.  Maybe try there?

Check the fuel cap vent isn't blocked. It happens on lawn equipment, but a pressure washer, meh.

Make sure the fuel is flowing. Its a gravity feed and the fuel line runs basically horizontal, it  takes very little to inhibit the flow.  There is usually a screen filter in the tank. 

If you look at the top of the carb, there's probably a black plastic screw that sets the low rpm.

Underneath that screw is a black plastic plug.

That plug is actually an air bleed.

Pull the screw out, pop the plug out with a small screwdriver and make sure the passages in the plug and the hole it goes into are clean.

If that doesn't fix it, replace the carburetor. They're usually under $50 on Amazon.

In reply to Dusterbd13 :

I'll second Fasted58's recommendation to check and see if the vent on the fuel cap is clear, cracking the cap slightly open can help diagnose that.

I'll also second Shawns suggestion of getting a new carb off the river site.   My Ariens snow blower got gunked up and even after a good cleaning it didn't run great.  I was able to get an exact replacement for less than $30 bucks and it runs better now than it ever did.  

On a less likely tangent, does the engine have a low oil level cutoff on the side of the crank case?  If so, check the oil level (obviously). If it's good search for some videos on how to diagnose the switch.  If I'm recalling correctly they will short the ignition to ground on low level and stall the engine much in the way you're describing. One of my Briggs generator engines had one go bad, pulling the wire off the switch and taping it got me going until I could order a new one.

Plugged vent makes a LOT of sense. Ill crack the cap and see how long it'll run. Hopefully i replaced a perfectly good carb with a perfectly good carb 

I revived my 212cc pressure washer a few months ago after it sat for a couple of years. I cleaned the carb but it kept dying. It was sucking up all kinds of crap that was in the tank. So I flushed the tank like a dozen times, replaced the filter/hose barb thing and fuel line.

That fixed it.

Check the oil. A lot of these little motors have low oil sensors that cut ignition. 
 

Pull the plug and clean it up with a small file or a pocket knife then set the gap. Check that you are getting spark by grounding it out on the case.
 

Pull the hose off the carb and check for flow. If it's not flowing or just dribbling, pull the hose off the tank and clean the little filter in the hose. If that doesn't work, use an air nozzle and carb spray to back flush the fitting into the tank. 
 

If the carb has two lines to the tank, make sure the vent and fuel lines aren't swapped. I did that on a string trimmer. It would run perfectly for a few minutes and then choke out starving for fuel. That was frustrating for about 20 minutes. LOL
 

My 2 stroke leaf blower did this.  The pickup tube in the tank had a split and it would suck in air and gas.  Same symptoms.

Not sure if that's possible with this engine, but maybe that will spark something for you.

I bought a lawn mower from a guy that sold it because of this problem.  I have a much smaller yard.  Worked fine for me.  Sorry no help.

My similar experiences have resulted in a deep hatred of small engines.  Everything but the mower and snowblower are battery powered. When those go they will be replaced with electric as well. 
I have nothing helpful to add. 

I agree with the hatred of small engines. I had a lawnmower that was fluctuating up and down in rpms almost to the point of stalling,but never actually stalled. I tried adjusting the governor. It was so touchy trying to adjust that it was either actually stalling or over revving. The over revving part made me think I was on the right track,but I never could get it right. Good luck. 

I usually buy a carburetor and a spark plug. Then change them both. 

At $10, the carbs are almost cheap enough to make it not worthwhile to clean. 

The first thing I check on my small engines when they start losing fuel is to check the vent in the cap.  I frequently have dried mud in mine from bees starting a nest only to realize it's not the best place to raise children.

There is often a screen in the bottom of the tank.  Even if it looks clean, it can have a scummy film on it that prevents flow.

Cheap rubber hoses can swell and restrict flow

They are also pretty sensitive to oil levels.  The governor inside the crankcase is basically a plastic paddle that moves more or less based on how much oil the crank throws on it.  I could always tell when my snowblower was low on oil because it would default to WOT.

My pressure washer is very sensitive to fouled plugs, usually i just take it out and hit it with some brake cleaner and a brush.  Pop it back in and it runs fine again. 

Hey! I actually worked in a small engine shop a few years back. But I have nothing new to add, so I'll double down on:

fuel! Flow, cleanliness, NO CORN!

oil. Full and fresh

just throw a new spark plug in. 

In reply to barefootcyborg5000 :

I actually disagree with the no corn part.  All of my small engines (2- and 4-stroke) get plain 87 with up to 15% ethanol.  When I'm done with them in the fall, I shove them in the corner and forget about it.  I just pulled my lawnmower out on Easter to mow for the first time.  Started on the second pull.  My 2-stroke string trimmer - 3rd pull.  My 2-stroke leaf blower - fired on the first pull, ran on the second pull.  The only one that sometimes gives me fits is my pressure washer because it sometimes goes a couple years without being used.  Even then, I just pull the bowl, run a wire up through the jet, blast it out with brake cleaner, and it starts first pull.

Ethanol isn't the evil that everyone claims it is.  Sure, it can make some white crusties on aluminum and brass, but it also mostly solves one of the biggest problems:  Condensation.  15% ethanol in one gallon of gasoline can dissolve about a tablespoon of water.

I also tilt my head like a confused dog when people go buy the rare-as-gold ethanol-free gas, and then put a stabilizer additive in it.... some of which contain ethanol.   And in the winter, we've all probably had to add gas line antifreeze.... which is alcohol.

I've just never had issues with small engines.  They're so dirt simple.  They're the ultimate in air/fuel/spark.  if you have them, it will run.

I hear that new small engines are jetted on the lean side for emissions, and therefore are very sensitive to any impediments in fuel flow.

Robbie (Forum Supporter) said:

I hear that new small engines are jetted on the lean side for emissions, and therefore are very sensitive to any impediments in fuel flow.

I can verify that you hear correctly.  Seems most of my older engines run best on full choke, full time.

So, it seems that oil level was the culprit. 

New cab and plug and fel line and filter didn't change anything before post. 

Running with fuel tank cap open didn't change anything. 

Oil was middle of the stick, so I figured that was ok. HOWEVER. That was with the stick being lowest point once I thought about it due to slope. Rolled it to the concrete, drained what oil was left and refilled. Proceeded to run it since about 5:15 tonight. 

That new 18 foot wand for the eaves and upper part of the house kicked me ass.