Steve r off the forum kindly bought on my behalf a set of GT550 pistons for nikasil cylinders from Cruisinimage. For some reason, my order was not accepted. I had asked him a few months back where the ring-retaining pins were, so may be his site put me down as a trouble-maker
Anyway, cost was £55 delivered and came in 4 days. Steve and I had a close look at them yesterday.
Set of three Pistons, rings, pins and circlips. Appearance excellent. Arrows on crowns. Ring retaining pins correctly located for nikasil cylinders. Weights very close at 173 +/_ 1g, identical to expensive Suzuki NOS. Sizes very close at 60.99, 60.995, 60.995mm. Ring side clearance in grooves are >3 but <4 thou, same as Suzuki Pistons. Because all aspects look the same and the weights also match Suzuki, the density of the alloy must be the same. Piston sides have a fine milled finish, which Suzuki Pistons do not. Pins are very close to weight of Suzuki thick wall at around 41-42g (accession from earlier, thin wall types weighing 30g). Only possible concern is that pin fit to piston is full sliding fit, falling through piston under gravity alone, dry. This doesn't happen with Suzuki Pistons, where usually, gentle warming is needed to get the pins home. Does this matter? Lower edges of Pistons are a bit sharper than Suzuki, but dressing with 600 paper cleans it up easily.
Based on others' experience in their bikes I wouldn't have any reservations about using these.
Cheers,
Mike
