GT185 pistons

[Flywheel]

My GT185 got a case of piston slap. Checked the timing, compression (130 for both) and cleaned carbon build up on the piston and head. All okay. Now have to tear down the rest of the top end and measure. Biggest GT185 piston available from Suzuki is 49.50 mm (+.5mm OD). Just curious what brand of pistons other GT185 owners run just in case I have to go over .5mm overbore. Are there other model's pistons that may fit with machine work?

[Zunspec4]

Hi flywheel,

Robinsons Foundry (major UK Suzuki dist.) has listings for +0.5mm and +1.00mm genuine pistons so they should also be available from your local Suzuki dealer too.

Cheers Geoff

[Flywheel]

Thanks for the reply but unfortunately the +1mm is currently unavailable at least here in the States.

[jabcb]

There are some 1.0 OS pistons on eBay for very reasonable money. You could order them now & keep them for your parts inventory if you don’t need them.

[Flywheel]

Well upon disassembly the right cylinder's piston pin showed signs of brinelling (flat spots) with the piston pin needle bearing falling apart upon removal. I would assume this was the non-rythmatic noise I was hearing not piston slap. Ring end was measured and was within spec (both cylinders) but before re-assembly with new piston pins and bearings I am going to have the cylinders measured.

Would anyone have any ideas what would have caused this and no other internal damage? Lean situation?, just faulty bearing and pin? age? Some previous owner's riding style?

[Flywheel]

Update: Replaced piston pins, bearings, circlips, gaskets and rings (since the top end was disassembled). Noise is gone.