A 44mm cylinder and piston kit for the pre-2021 engine in the Husqvarna 150BT, 150BF, 350BT and 350BF backpack blowers and the Jonsered BB2250, all built on the same 44mm, 50cc two-stroke engine. The kit contains the cylinder, the piston with rings, wrist pin and circlips, and the intake and exhaust gaskets, with installation instructions. It replaces cylinder 502848701, piston 502849601 (also written 502 84 96-01) and gaskets 502848801 and 511496901. The 150BT and 350BT were redesigned in 2021 with a different cylinder and piston, so look up your blower's model and serial number on its parts list before ordering: cylinder 502848701 or piston 502849601 means this kit fits, while the 531147153 piston kit means you have the newer engine. Choose the cylinder kit when the bore shows deep vertical scoring, flaking plating or aluminum smeared on it after a seizure; a new piston in a damaged cylinder fails again. Most of these failures come from a lean condition, so pressure and vacuum test the crankcase and fix the air leak or fuel fault before assembly, and use a ring compressor.
- CYLINDER, PISTON AND GASKETS - A 44mm cylinder, piston with rings, wrist pin, circlips, and the intake and exhaust gaskets, with installation instructions. For an engine whose cylinder is scored, where a piston alone will not restore compression.
- PRE-2021 ENGINE ONLY - The 150BT and 350BT were redesigned in 2021 with a different cylinder and piston. Look up your blower's model and serial number on its parts list: cylinder 502848701 or piston 502849601 means this kit fits; the 531147153 piston kit means you have the newer engine.
- FITS HUSQVARNA 150BT, 150BF, 350BT AND 350BF - and the Jonsered BB2250, which is built on the same 44mm, 50cc two-stroke engine.
- REPLACES 502848701, 502849601, 502848801 AND 511496901 - The cylinder, the piston (also written 502 84 96-01) and the two gaskets. If your parts list shows these numbers, this kit covers them.
- WHEN THE CYLINDER HAS TO GO - Deep vertical scoring, flaking plating, or aluminum smeared on the bore after a seizure. Before assembly, pressure and vacuum test the crankcase and fix the air leak or fuel fault that caused the failure.