2 Stroke Engine Help

i went all in and got Toro electric everything. There are more powerful units out there, but the electric push mower was enough for about 8k sq ft of yard off a 7AH battery. TBF, i borrowed my friends Toro gas mower to compare and it did do a better job. Just not enough so that I'd want to use it more than my electric version.

 

I got the Toro snowblower and would do Toro for the mower to have like battery set up. All my other stuff is Craftsman, but for the frequency of mowing, I'd get something a little better than the Craftsman.

 

Correct

 

its a Walbro A021000122 carb. there are versions on **Ama-zon*. $30-40
Some carbs have the adjustment screw capped.
you just pry off the plastic to expose - done for emissions. not sure if yours has that.
these engines (2 stroke carbs) have become real problems with Ethanol gas.
If you let it sit for a couple months thats all it takes for the gas to start going bad and gum up the carb. Its important to use Stabil 360 or like with it, Keeps it good for one year.
Its important if it will sit for a while to burn off the gas and dump the gas out of the tank.
People will bring these engines in for repair - they charge 1 hr to diagnose and repair time on top.
Thats more than they are worth so they become disposable.
The other thing is that 2 stroke oil mixed with gas does does not adhere to ethanol which makes up 10% of the gas volume.

 

If it's 4 stroking (firing every other revolution) the mixture is too rich. Can you pull the plug and post a close up picture of the business end? Did you oil the airfilter?

 

It's a 2 stroke but it sounds like a 4 stroke when full throttle. LOL. I'll have to get to it tomorrow.

 

I don't fully understand why 2 stokes do this. I set the main jet so it starts to 4 stoke at redline with no load. Of course my definition of redline is subjective. On a chain saw I adjust the mixture so it starts to 4 stroke slightly past the speed the saw cuts soft wood with just the weight of the saw. On string trimmers, the RPM that it runs no load with a small amount of string. On my blowers I set them to just slightly lean of the 4 stroke rich setting.

A black or wet plug is a sure sign of running rich.

 

Sounding subdued and quieter.
there is something glorious about a 2 stroke starting up - rum pah pah pah....
and at full throttle. lol
I have many of both 4 stroke and 2 stroke including outboards.
The Hondas run nice and quiet but I love the 2 stroke Yamahas.
My Milwaukee tools have pretty much replaced the corded tools.

 

Replace the fuel lines, same issue. Replace the carb, no change. New spark plug, same. Old spark plug was “wet” a bit. I tried adjusting the carb but don’t know what I’m doing.
Maybe the engine is just done?

 

Take a plastic syringe put some gas from tank in it. Squirt gas directly into cylinder. Insert plug try again. Choke off. Dry off spark plug. If it fires up and burns off the gas and dies it's a fuel problem. Make sure the lines are set up correctly in and out of carb. In to the carb and out to the gas tank. Sometimes they get reversed. Is there a purge bulb? If they are correct it should fill with gas and purge the air out.

https://youtu.be/3hYoo775X8U?t=253

 

The spark plug was wet? There could be a few different reasons for that.
Sometimes, chasing the problem that far just isn’t worth it for a small tool. It’s kind of liberating to throw it away and just buy a new one. With that said, my lawnmower was almost 40 years old when I finally ditched it a couple years ago. I kind of loved the fact that I could rebuild it and keep it going.
Since you found it wet, that means combustion isn’t happening or not happening enough.
Is the spark plug the right type? Some machines use radio frequency for ignition timing (found that out the hard way).
Is the carb blowing too much fuel into the cylinder? Look up a video on how a carburetor works.
Is there compression? You can feel for this if you cover the hole where the spark plug goes with your finger. Cover it and pull the starting rope. Do you feel pressure pushing your finger away?
I apologize if these points are things you already know- I hate when people assume I don’t know something. It’s easy to get mixed up when diagnosing a problem with a lot of variables. Hopefully something here helps you.

 

I look at that plug and see one that had been running the majority of it's life at the proper mixture but recently started running rich. Go back to your old recipe for gas/oil, buy a new plug of proper quality and go back through your past attempts to repair and make sure you didn't add to the original problem which was most likely canned fuel.

 

There is a purge bulb, but it's on the bottom of the carb. I'll check the way the flow is going and try the spark plug thing as well.

 

I appreciate the help. I have a decent mechanical knowledge but this one is a stumper. It ran good when I used hand mixed fuel/oil, then ran really well when I did the pre-mix, but something fell off after using it a few times to where I am now. I'll check compression and look at adjusting the carb. Maybe I needed to adjust it while at WOT instead of idle.

I'm probably holding on to it too hard since it was my dad's that I inherited. Yes, it's just a machine, but there is a tie there. I also have just felt very wasteful with some of this stuff over the past few years.

 

Yes... you must tune while holding WOT ... Is there 2 adjustment screws ? If so... One will be for WOT and the other for throttle acceleration.. Meaning adjust so there is no bog when you go from idle to WOT .. And then there should be another one to adjust idle itself up and down ...

 

There are 2. One is like an idle stop, then I'm guessing the WOT adjustment. I'll mess with that and see what happens.

 

Update cause I know you all have been on the edge of your seats. I gave up on this after a while. I'm emotionally involved with this since it was my dad's. Not that having emotions for a piece of lawn equipment is healthy, but it is what it is.

Anyway, I started thinking and playing around with it. I felt like there was an exhaust leak as you can see the burnt spot on the OG picture to the right, but had resealed the muffler and heat shield. I also thought that had been there for some time. So I came to the conclusion the head gasket might have failed. Broke it down, and couldn't see any smoking gun. But while in that process of ordering new gaskets and after looking at part diagrams more carefully, I think I had installed the exhaust gasket in the wrong spot. Then, diving deeper, I wanted to see what the spark gap should be. I though I saw it was supposed to be .30mm when it's supposed to be .65mm.

Needless to say, I hope that it was just a dumb error on my part with spark gap, but now I have to wait until gaskets come in to see. At the very least, I got to clean everything up really good and this was a first in tearing an engine down myself. There was some carbon build up on the exhaust outlet that I got cleaned up.

I wish I would have torn my dads tools down as a kid more now. LOL

 

Even if you never get it going again, the time spent with it is a bit like some time spent with the old man. It’s serving its purpose. Hope you get it going again though.

 

IDK why but that made me well up. Thank you.