ENGINE DISASSEMBLY 
14. Remove the sprocket nut, washer and the sprocket.
15. Tap the end of the fifth driven gear in the right case with a soft mallet until it is free of the bearing.
16. Remove the sprocket distance spacer from inside the transmission oil seal.
17. Pry the small oil seal from the center of the fifth driven gear with one of the clutch push rods.

CRANKSHAFT AND BEARINGS

Removal

1. All of the bearings and bushings in the Ossa engine must be removed and installed by heating the engine cases.  This allows the removal and installation without any force being applied to them.
 

NOTE: Do not drive or press the bearings in or out.  This will damage the bearings and perhaps the cases also.  If the bearing or bushing cannot be removed easily, it means the cases have not been warmed enough.  If the case temperature is correct, no force should be required to remove them.


2. Heat the primary side engine case with oven or electric stove or torch until the case temperature reaches 250-300 degrees F. If use a torch, be sure to keep the torch moving to heat the whole case evenly.  Do not overlie the cases, since they may distort after reaching an excessive temperature.  Always heat the whole case to prevent warping.
3. Don't let the flame of the torch touch the crankshaft seals if you plan to use them again Too much heat will damage them.
 

NOTE: You should replace the seals every time the crankshaft is removed or the cases separated.


4. After heating the left case, wrap a cloth around the magneto side drive shaft and p the crankshaft assembly out of the case.  The primary side main bearing will remain on the crankshaft.
5. If the crankshaft is difficult to remove, sup port the case on a wooden box so the crank i hanging freely (see Figure 21).  Tap the end o the primary side drive shaft with a soft mallet to remove it.

6. Remove the transmission main shaft bearing and the lay shaft bushing for replacement while the cases are still heated.  Ta ,p the bearing with a soft mallet and the bushing with a drift to tap it out.
[previous page] [index] [next page]