Kingartiv

[]When I removed the piston & conrod, I forgot to mark it's orientation. Now I'm trying to determine which way the piston gets installed on my OS 61fx. The sleeve has a "V" that aligns with a pin on the block to ensure it is aligned correctly. The only sign I can find for alignment on the piston is a "bump" on the underside of the piston next to the journal for one of the wrist pins. Can anybody help me out? If not, I'll take my 50/50 chance since I didn't remove the conrod from the piston.

Cheers!

Art

Flypaper 2

There usually is a chamfer on one side of the bottom of the rod where it fits on the crank. the chamfer goes toward the crank side.

w8ye

My Feedback: (16)

Often there are "ARC" scratches on the back side of the rod where it has rubbed the back plate.

The piston is usually darker on the top edge near the exhaust.

Enjoy,

Jim

Kingartiv

First, thanks for your replies! I think I need to clarify a little though... I pulled the piston and conrod out as an assembly by removing the sleeve first, then sliding the conrod off the crank and removing the piston/conrod assembly out the top of the block. Then, I cleaned all the parts, so the piston is too clean to see the exhaust port side- but that's a great idea! The only distinguishing mark I can find is on the piston. When I look up past the wrist pin, one wrist-pin journal has extra material molded into it that could be a counter weight or indication. I'll stop by the local hobby shop today as well to see if they can take a look- if you have other ideas, I'm sure open!

Cheers and thanks again!

Art

TimC

Art, Flypaper 2's tip is what I'd look for. One end of the hole for the crank pin at the big end of the connecting rod will be beveled to match the slight radius at the base of the pin.

w8ye

My Feedback: (16)

Tim C's and Flypaper's deal about the chamfer at the end of the big end bearing is what I generally use. I was just trying to present some of the other alternatives.

Enjoy,

Jim