Squish Band Pistons

[Curt Henry]

After 9 months I finial pull the 92 R100GS out of the corner to start putting the bike back on the road after dropping a valve.
The Nikasil cylinder I purchased off of E-Bay, the piston that came with the cylinder maybe a Squish Band Piston. The pistons I received is a flat top, the piston I removed from the undamaged left cylinder is dome top.

For the good news I only found aluminum from the damaged piston in the oil pan, no steel. All the chunks of metal where large and I found no metal in the oil filter. I need to take the rods to Crank Shaft Supply here in MPLS and have them checked for straightness and cracks. I few more parts including a piston and the R100GS will be back in the dirt.

[bbelk]

Are you going to have that all done by May 12? If not, I guess you have to make the trip on an Airhead - but thats ok.

[John Falconer]

How many machined bands are there in the area of the piston between the top ring groove and the top surface at the outer edge of the piston?

[Curt Henry]

There are 6 groves between the top of the piston and the top ring.

[John Falconer]

Then those are (unless my recollection really slips here) the 9.5 squish band pistons from '77 and early '78. If you have almost any of the other pistons and hold them up to these, aligning by the top ring slot, you'll find the squish band pistons "taller" from the top land to the top of the piston's edge.

[John Falconer]

OK - talked to-be-ex-wife through the server resets last night and pictures are back up.

Here's a "squish band" 9.5 piston picture for you:



Additional related info is at
http://www.moragafalconers.org/photos/i ... /&page=all

Good luck, John

[Curt Henry]

Thanks John, I now know that the piston I receive is not a Squish Band but an early 80's low compression piston.