How to Troubleshoot a Husqvarna 359 Carb

The Husqvarna 359 chainsaw uses a filtered compensated carburetor, like a lot of two-cycle engines. This carburetor can often be the cause of most engine problems for these saws. After a few years, old gas deposits build up a sticky residue in and around the carburetor, which if not cleaned properly will eventually wear out your carburetor. Still, the carburetor is one of the more complex components, with a lot of parts that can break down. You shouldn't attempt breaking the carburetor down and rebuilding it without some prior small-engine knowledge.

Screwdrivers

Toothbrush

Rag

New fuel line and filter

Carburetor cleaner

Wire brush

Carburetor Kit

Start the saw, if you can, and adjust the idle with low- and high-speed carburetor adjustment screws. These screws regulate the gas-air mixture in the carburetor and may give you a quick fix to your issue.

Drain the gas tank. Run the saw, if you can, until it burns out all of the fuel in the line and carburetor.

Wrap a rag around the toothbrush, spray a little carburetor cleaner into the tank and clean the entire tank with the brush. Remove any debris or dirt in the tank. Check the air vent on the gas cap and the seal around the fuel line for any cracks or damage. Replace if necessary.

Remove the old fuel line and filter. Replace both of these inexpensive parts with new ones. This can also solve a lot of carburetor issues.

Remove the entire carburetor from the engine. Break down all of the parts, including the seals, diaphragm and gaskets. Soak these in a carburetor bath for at least one day. Scrub them clean with a wire brush.

Check the diaphragm for any warps or cracks. Install the carburetor kit upgrade according to the manufacturer's guidelines. Replace the seals and gaskets. Rebuild the carburetor, and don't forget to check the metering arm lever's height for proper distance.

Check the needle valve to make sure it still opens and closes. Check the crankcase for any worn seals or damage. Make sure the crankshaft still works.

Work your way through to the piston, checking all of the seals and rings. Make sure the piston hasn't cracked the cylinder head or bore. Check the exhaust port for any clogs. Replace the spark arrestor screen inside the muffler.

Reinstall the upgraded carburetor and see if the saw will run properly. If you still can't get the carburetor working right, make sure you installed the seals and gaskets properly. Otherwise, replace the entire carburetor with an aftermarket one.

Do not remove or disassemble the carburetor if you're unsure about how it goes back into the saw.

The 359s are known to have carburetor issues. Contact a Husqvarna mechanic or retailer for further troubleshooting.

Whenever you find a fix that works, remember to adjust the carburetor when you first run the saw again.