Surging motor on NEW carb!?

l008com said:
Engine doesn't smooth out per say. It does get smoother at higher RPMs but it still surges a bit.
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Reason why I mentioned to try it WITH the air filter on and at 3600rpm. Filter will richen it up a touch.
l008com said:
OP didn't ignore the suggesting to set the revs to 3600, OP asked how you do that on a carb with no adjustment, and OP was ignored.
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LOVE the reply, just love it. (y) (y) Should be a spring on the throttle/governor linkage that connects AT the throttle end AND the other end a stationary metal tab. More you tighten the spring or remove slack, faster she will run.
l008com said:
I have inadvertantly drained the tank when I took the carb off while the tank was full, the fuel flowed very freely.
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How much fuel ran out? Palm full? Quart? Makes a difference. You can fill the tank with Diesel and do the drain test. Drain a FULL tank into a jar. At ALL times, nice fat flow of gas, tank cap ON too. Diesel is not as flammable so much safer. Should have a Diesel can to clean carbs and various other greasy, oily and dirty parts with. Use an old paint brush and paint tray. Clean away all kinds of stuff. Diesel vs brake cleaner, Diesel is way cheaper and a ton less caustic on the lungs. Stop buying brake cleaner. Gallon of Diesel will last you and me a year plus easy.
l008com said:
I did test the spark with a spark plug tester. I don't know the difference between different kinds of testers so I don't know what kind I have? But it was flashing, showing spark. I think I have video of it.
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You need to test at low, mid and high revs. Also need to open the tester gap up to properly test the coil under simulated cylinder compression. What I call stress the coil out. At a distance point the coil will stop sparking.
 
Here is Taryl in action. The meat and taters starts at 5:00 - 7:00. Watch the entire video where he explains gap jumping and proper spark testers. This will answer a lot of your questions.

Notice he had spark at low revs only. At mid and high revs he had nothing. Bad coil alert........

 
So I may have the 'wrong' type of spark tester, but thats all I have so I figured all this talk of spark, let me run the machine for a few minutes off the spark tester and take a close look at it. THEN i ran my perfectly running honda mower off the spark tester too, to compare. The orange bulb was flashing much brighter and more consistently on the honda, vs the yardman (the mower this post is about). I'm going to do more testing but its really starting to look like a bad coil. I had a spare too last year and I ended up tossing it, bummer.
 
QUESTION:

I've removed the flywheels on many snowblowers but never a lawnmower. Does the same trick work? Unbolt it, wedge a flathead screwdriver under it, and give it a decent tap with a hammer to pop it free? Is it there a different/better way to do it with lawnmowers?

I haven't actually checked to see if the flywheel key is sheered. I doubt it is but I might as well check before I throw a new coil on there. I haven't checked the coil flywheel spacing either, but if that gets loose, the magnet pulls them together, not pushing them apart, so I really doubt thats the problem. Someone could have installed it wrong but when I had the flywheel cover off, it didn't look like anyone had been in there recently. Recently meaning within the last 10 years.
 
l008com said:
I'm going to do more testing but its really starting to look like a bad coil
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IF you had an open gap style tester, you would of found your answer long ago. You would see a tiny orange zip when you needed a blue SNAP.

Here is a good cheap one off Fleabay. I have one, it works for what I need. Also have the PET-4000 Cadillac top of the line tester. This one is 8 bucks to your door.

 
Can also use a simple 12 volt test light grounded to bare metal. Can move the pointer end out away from the plug boot to stress the coil out.
 
Well, the current coil looks perfectly lined up. And the flywheel key looks perfectly aligned too. So I've got a new coil on the way. Fingers crossed. I know many think its a fuel issue, I guess we'll see.
 
New doesn't mean new these days. Put your credit card away and TEST what you have. 6 pages now with no resolution. You are not listening to anyone on here.

I gave you simple and cheap ways to test for spark. Spark is pretty important for starting and running. Take a piece of wire. Solder on a clamp or crimp on a ring terminal. Put the ring terminal behind a good clean block bolt. Use the other end to place inside the plug boot. You can move the wire away to stress the coil out.
 
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