Hi you all, today I helped a friend dismantle his Tower 75 (Used to be mine) for cleaning and inspecting the bearings and crank after a lawn dart manouver he pulled on frozen soil. In the exitement I forgot to mark the conrod or notice which side is facing front or rear, before removing the setup from the case[sm=red_smile.gif] Usually there is a oilhole at the big end that is facing forward, but the Tower 75 doesn`t have this, but rather two oilholes underneat the big end. The only reference now is the wristpin and the little clip that stops it from coming out of the piston. The big question is if the end with the clip is facing front or rear when the engine is assembled correctly????? I would be grateful if someone knows this.

Asmund,


Please look at the con-rod bottom end...

The bronze bushing should have a chamfer, or a bevel on its inner lip, on one side.

The side with the chamfer faces forward - toward the crank-web.
The flatter side faces the back-plate.

The side that faces the backplate will probably also have wipe-marks from contacting the back-plate.


If you still have the piston on the wrist-pin assembled, the somewhat blackened side of the piston faces the exhaust.

Yes of course, that makes sense. I will take a closer look at it tomorrow, thanks alot Dar[8D]

Hi Asmund,
Al so look at the top of piston for flow pattern.
You should see some sign of the port lay out.
Just my $.02 .