Motorturns over hard with pullstarter on my gx340 pressurewasher

should be an internal govenor on a plant unit like that

...
there is a thicker than normal metal rod running off the carby to the motor and that is where you adjust the govenor

cant find good instruction how that governor is adjusted ..if adjusted the wrong way it will rev out may even throw a piston

then check carby idle adjustment
should hunt (rev up and down only slightly )as load changes
you tube
11hp Honda GX340 cold start
https://www.youtube.com/watch?v=i3_v68__X5o




Honda GX340 HGI Parts

-Take the handle off the rope. You want to only have one knot in one end of the rope. (Of course, if the rope's already broken, you can skip this step ....)
-Get the reel and lay it facedown.
-Get the coil, and begin carefully winding it up so that it fits inside the grooved edge on the reel. BE PATIENT - this will take time.
-On the inside of the coil, there should be a little hook on the end of the coil. That hook matches one inside the pullstart cover when you put the two pieces together. The trick is to get the hook on the reel to catch the hook on the pullstart cover. CAREFULLY put the reel and coil inside the cover, and ***** the bolt in for a moment to hold it in place.
-Turn the pullstart reel clockwise until you feel the hooks catch each other. Feel some resistance? Good, that's what you want.
-Take the bolt back out, and reassemble the starter pawl assembly inside the pullstart, then put the bolt back in and tighten it.

You should now have a complete assembly, minus the pull rope. -Now, looking down into the pullstart, notice there is a hole in the reel off to one side. This is where your rope threads through. Grab the reel, and crank it around about .... four or five times, and try to get the hole in the reel lined up as close as possible with the outer hole in the pullstart cover. -Take your rope (you DID take the handle off first, right? Oh yeah, it broke off ...), and thread it through the reel, then through the outer hole in the cover. This will be a little tricky, as you need to be holding the reel so it doesn't unwind ...
-SLOWLY let the reel start to retract, but don't let it go all the way. Does it look like it's drawing the rope all the way back in? If so, great! If not, pull the rope back out, crank the reel around another turn, and try again.
-Once you have the reel set to where it will retract the rope all the way, thread on your handle and tie it off. You're done!

Excessive fuel entering the inlet manifold, carby needle and seat not shutting of fuel flow , remove and clean fit new gaskets and needle and seat if worn.

sounds like the gears on the pullstart mechanism is starting to get stripped there generally not expensive a small engine parts store can get it for you

Align crankshaft and balancer gear first. Rotate crankshaft and align timing gear. Alignment mark may be hard to see on crankshaft for timinig gear.

You must first remove the shaft assembly by removing the Torx/Flathead screws that hold on the trigger. Then you remove 3 screws that hold the engine to the shaft. Next you can remove the shaft assembly and you will see 4 or so screws holding the black surround around the clutch. You need to remove this to get to the pullstarter. Once you get to the pullstarter make sure not to release the coiled spring or you'll have a hell of a time putting it back in. Typically that are behind the pullstarter assembly.

If after removing the starter the starter pulls easily but you can not turn the flywheel the engine is probably seized. Could be a piston failure or a bearing failure. check to be sure nothing is caught under the flywheel binding it up.

You can remove the cover and you will then be able to view the pulley and crank as well. You can pry up tabs on pullstart, rewind and replace.

it mus be over heated.