Bearing removal and
assembly using the
JETT removal and assembly tools
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Warning: Heating the case above 325 deg. F. Will affect the heat treat of the crankcase material.
Bearing Removal:
- Disassemble the engine by removing the head, piston and liner, crank and carburetor.
- Drive out the front bearing using a 1/2" diameter wooden or plastic dowel. (the engine does not have to be hot)
- Place the case in a preheated 325 deg. F. Oven for 12-15 min.
- Quickly, but carefully remove the case from the oven using a pot holder, or insulated glove and drop the bearing removal tool (large ground end first) into the front of the engine. The bearing should fall out the back, along with the tool. If not, tap on the bearing removal tool to remove the bearing.
- 4a. If you do not have a bearing removal tool rap the bottom of the case on a piece of wood to remove the rear bearing. If it does not come out, then reheat the case, reseat and align the bearing with the crank and try again.
- After the bearing has cooled it may be removed from the tool by taping it around its edges, or by pressing it out with your drill press.
Bearing Assembly:
- Make sure the case is clean.
- Place the case in a preheated oven at 325 deg. F. For 12-15 min.
- Place the rear bearing on the bearing assembly tool. Lay the front bearing in a convenient place.
- 3a If you do not have a bearing assembly tool then use the crankshaft as an assembly tool.
- Quickly, but carefully remove the case from the oven using a pot holder, or insulated glove and place the case over the assembly tool and rear bearing. The rear bearing will slide in place.
- Quickly place the front bearing over the assembly tool and slide it into the front housing. Place the brass knocker over the front bearing and tap the bearing into its seat.
Caution!! If the front bearing does not easily slide into the front housing, only tap gently. It is best to remove the front and rear bearing and start over. Check the front housing for burrs and foreign matter before repeating the process. The technique is easy and foolproof. If the parts do not go in easily, there is a problem. Clean the case, inspect for burrs, and increase the time in the oven (not the temperature).
