Carburetor Assembly for Husqvarna T540XP Mark II

This T540XP Mark II carburetor assembly is a replacement for the carb on Husqvarna's professional top-handle saw. It is the fix when a saw will not idle, hesitates, or runs poorly and the cheaper causes have been ruled out.

Check the simple things first

Most running problems on a top-handle saw are not the carburetor. Before replacing it, check for stale or wrongly mixed fuel, a clogged fuel filter, a dirty air filter, a fouled spark plug, a blocked spark arrestor screen, and cracked fuel lines. Old ethanol fuel left in a saw over the off-season is a common cause of varnished carbs.

If the saw still will not hold an idle, bogs, or floods after those checks, a new carburetor assembly is often faster and more reliable than rebuilding a varnished one, especially on a climbing saw you depend on.

Prevention is cheaper than a new carb. Use fresh, correctly mixed fuel, consider an ethanol-free or pre-mixed fuel for saws that sit, and run the tank dry before long storage.

Installing it

The T540XP Mark II uses AutoTune, so follow Husqvarna's procedure for fitting the carb and letting the system relearn; a dealer can also check it with Husqvarna's service tools. Reconnect the fuel line and throttle linkage carefully, and confirm the chain does not turn at idle before using the saw.

Shut the saw off and let it cool before servicing. A saw that runs badly aloft is a safety problem, so test it on the ground first. More parts are in chainsaw parts.