Piston Ring 545154001

Removed the engine from the blower housing. Unbolted cylinder/head from the crankcase. Installed the new piston ring. Reassembled the blower. The only problem was getting the new piston ring compressed enough that the piston could slide back into the cylinder. I used a worm type automotive hose clamp as a piston ring compressor.

Unit will have to be completely disassembled so remember (i.e. take pictures) as you go. Remove carb. and fuel tank at the same time and leave hose hooked to carb. Got to the other side and remove plastic cover over exhaust muffler and remove muffler, gasket and metal deflector. Remove carrying handle (2 screws) and the top plastic cover. At this time you can remove spark plug if you desire...........or you can wait until later.
Bottom side of unit............remove 3 screws covering and protecting fan and set cover and screw aside. Hold fan and remove nut, lock washer and large flat washer. Set this aside also. Remove fan duct and nozzle (4 screws) and set it aside. Now all that is left is the lower housing (4 screws) Remove screws and housing and set aside.
Flywheel is exposed at this point and (in this order) you will find a space and washer (washer is next to flywheel. Remove them and set aside. Gently work flywheel back and forth.......a little lubricant between shaft and flywheel will help. Shaft is tapered so it will come off with a little effort.
Next I took the two allen head bolts holding the cylinder head on. Set them aside and remove head. I removed the piston and rod assembly due to over-heating and or lack of proper lubricant in fuel. To remove the assembly the "black" cover (2 screws) on rear if engine block will have to be removed.
To reassemble everything is reverse from disassembly. I used RED Loctite on the cylinder bolts and BLUE Loctite on the Fan Nut and shaft.
Main culprit I found was the piston ring was frozen to the piston and the cylinder was scored. Compression was dismal and what I suspected was proven once the unit was disassemble.
Make sure you have a good supply or Torx screwdrivers and bits (various sizes) along with a good Allen Wrench set
Don't forget to watch for the gasket behind carb. It will come lose and may wind up on the floor when you remove the carb. Same goes for the exhaust.

1. Took the assembly apart
2. Tested compression
3. With the poor compression, went to look at piston closer and broke piston ring in the process which must have been weak to begin with.
4. Ordered new piston rings and gasket kit to replace all the gaskets since engine assembly was taken apart.
5. Put together remaining assembly
6. Applied high temperature adhesive and let cure over a few days
7. Tried starting the blower and it ran great!

1 Removed engine
2 Removed cylinder head
3 Removed old piston ring
4 Installed new piston ring
5 Reassembled and reinstalled engine

Disassembled blower motor, installed new piston and ring.

replaced piston ring

I disassembled the outer plastic housing to gain access to the motor. Once I had access to the motor I performed the disassembly in the following order:

Removed the carburetor and spacer, held in with two screws. Removed and replaced paper gaskets.

Removed the exhaust and heat shield, held in with two screws. Replaced exhaust gasket

Removed the cylinder, held in with two machined screws. Replaced rubber base gasket

Removed piston assembly and ring.

Cleaned and checked the piston and cylinder bore for gouges. Removed and replaced cylinder ring.

Reassembled in reverse order.

disassembled blower
removed old piston ring
cleaned piston ring groove
installed new piston ring
reassembled blower

Stuck ring in craftsman 358-797342 vac/blower with low compression. Ordered and replaced ring, and brought compression up to 90psi. Starts on one to two pulls now. With a new carb, runs like new. All I did was replace the single ring. Did not hone out the cylinder and did not replace piston.

time to complete, well I wasn't in a hurry but took a few hours.
Steps:
clean parts swap the new o-rings/gaskets and the new piston ring,, lock tight bolts and hope they hold over time.
Note: piston ring breaks during disassemply so just pick it out and take a broken piece to use to scrap and clean the ring groove.