MRC Forum- brought to you by www.morini-riders-club.com

Hi,
I recall Guzzi had some bikes with chrome cylinder bores; which at times cause issues or reported too if the age and flake.

Of the “older” wee-vees did they ever tread that path and use chrome bores. Guess not the original drum brake models but what about the others?

M

Newer air-cooled V twins use similar coatings. It's called Gilardoni which is very similar to Nikasil (I'll let others go into the details). So later models of Kanguros, New York's, Darts, etc. have them (of course there may be exceptions given the history of these bikes and the passage of time). Here's an example of a discussion of these on the forum viewtopic.php?t=5534

I think the surface is Nikasil, and Gilardoni the name of the producer, but not 100% sure. As far as I know the Gilardonicilinders are mounted in K2, (not sure if K1), Kanguro from X2 on (85 upwards), Dart,Coguaro Excalibur and New York 350 and all the 501 motors. These cilinders need other pistons and other rings with much less clearance than the the old ones. There are two great advantages with these cilinders: better compresion (better starter and probably less noise) and the best: there is no wear in the barrels! So if the bearings are ok and the piston pins won´t come out, the barrels and pistons are nearly eternal. Normaly you only have to change the piston rings after quite a lot of km without rectifying the barrels or the need of oversized pistons. These rings are expensive (but less than oversize pistons plus boring) I changed my rings after 70mil km in a 501, the barrels looked like new and the pistons still in quite good condition.

The barrels have Gilardoni cast into them on the outside. My X3 and Excalibur cylinders did, anyway. K1 of 1981 has standard liners. May have changed at K2 model, or maybe later K1s had the new fangled chrome bores?

Paradoxically my Kanguro X (the first model with drum brakes) has these later barrels, however they could well have been fitted in the many years after the bike left the Morini factory.

mhsilverw wrote: ↑31 May 2021 17:42 Hi,
I recall Guzzi had some bikes with chrome cylinder bores; which at times cause issues or reported too if the age and flake.

Of the “older” wee-vees did they ever tread that path and use chrome bores. Guess not the original drum brake models but what about the others?

M

Unlike Guzzi, Morini never used chrome-plated bores. Either iron liners or Nikasil/Nigusil.

Both Nikasil and Gilardoni are trade names.

It's Silicon Carbide disolved in Nickel. It's very durable, except where there is poor quality fuel with excess Sulphur.

My K2 barrels are stamped Gilardoni