Greeting, I recently acquired a McLane 3.5 HP edger that was not running. I removed the Pulsa-Jet carburetor and tank. I cleaner the carb and replaced the diaphragm and noticed the cup was missing on the spring, so I found a new cup and installed on end of spring. I cleaned the tank and installed new plug. Drained oil and refilled. Motor starts with full choke and throttle. If the choke is opened too much the engine begins to rev and then slow and then repeats over and over. It has the Air Vane type governor and I am thinking it may have something to do with that. Any suggestions would be appreciated. Thank you
McLane 3.5 HP edger- Revs and then slows and repeats, surging
- Thread starter dgsj
- Start date
ILENGINE
Lawn Royalty
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Carb not clean enough. Surging is almost related to a dirty carb, unusually in the idle circuit. Since carb engines run on the idle circuit even at full rpm with no load.
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McClane is just the brand of the edger. The engine is a Briggs and Stratton.
Is the carburetor bolted tightly to the engine?
I think you are describing a surging up and down problem.
Did you adjust the mixture needle on the side of the carburetor?
I suggest you remove the needle and spray some carb cleaner in the hole to clean the passage. Then install the needle until it lightly seats. Back it out about 1-1/2 turns for a good basic starting position, then see if it fires up. It may take a little minor needle adjustment to get your best RPM.
The air vane governor is only responding the airflow from the flywheel air fins (Make sure it does swing freely on the shaft bolt.)
The carburetor straining for a proper fuel mixture is the root cause of the problem.
You may have to inspect the tube and screen in the tank that picks up the fuel. The fine screen could still be clogged partially, or the tube has a lengthways crack in it (rare). Old fuel resin can be difficult to soften and remove. I recommend Berryman Chemtool B-12 carburetor spray, it works.
Is the carburetor bolted tightly to the engine?
I think you are describing a surging up and down problem.
Did you adjust the mixture needle on the side of the carburetor?
I suggest you remove the needle and spray some carb cleaner in the hole to clean the passage. Then install the needle until it lightly seats. Back it out about 1-1/2 turns for a good basic starting position, then see if it fires up. It may take a little minor needle adjustment to get your best RPM.
The air vane governor is only responding the airflow from the flywheel air fins (Make sure it does swing freely on the shaft bolt.)
The carburetor straining for a proper fuel mixture is the root cause of the problem.
You may have to inspect the tube and screen in the tank that picks up the fuel. The fine screen could still be clogged partially, or the tube has a lengthways crack in it (rare). Old fuel resin can be difficult to soften and remove. I recommend Berryman Chemtool B-12 carburetor spray, it works.