Done a top end freshen up on my berg at 550 hours, it really did not need it appart from the buggered counter shaft. It was running great, no oil burning, So done a few bits and pieces including a Prox piston. Have just pulled it down at 650 hours because it is burning oil, not heaps but 200 mls in 450k light adventure riding. This is what I found, make your own conclusion from it. I have made mine.
The Prox piston rings are no where near as substantial as the OEM not only in the ring tension but size. The compression ring has very little tension there is none on the 3 piece oil controll rings. Not that they have much any way, but I mean None.
The bike has not been hot, nor had any dirt etc... Through it. The barrel is great condition.
The OEM piston has 550 hours, on the same piston rings. I removed them and Slid them into the barrel this afternoon and measured the end gap, to give me a rough idea of wear.
Compression ring .35 mm, 14thou
Oil controll ring .38mm, 15 thou
The Prox rings had after around 90 hours
Compression rings .38 mm 15 thou
One of the 3 piece oil controll rings .457 mm 18 thou
So they have worn around the same give or take a bit.
I won't be buying another Prox piston for my berg. The rings look like they cheap. May be I am expecting too much out of a non OEM piston and rings???
The Prox piston rings are no where near as substantial as the OEM not only in the ring tension but size. The compression ring has very little tension there is none on the 3 piece oil controll rings. Not that they have much any way, but I mean None.
The bike has not been hot, nor had any dirt etc... Through it. The barrel is great condition.
The OEM piston has 550 hours, on the same piston rings. I removed them and Slid them into the barrel this afternoon and measured the end gap, to give me a rough idea of wear.
Compression ring .35 mm, 14thou
Oil controll ring .38mm, 15 thou
The Prox rings had after around 90 hours
Compression rings .38 mm 15 thou
One of the 3 piece oil controll rings .457 mm 18 thou
So they have worn around the same give or take a bit.
I won't be buying another Prox piston for my berg. The rings look like they cheap. May be I am expecting too much out of a non OEM piston and rings???
Last edited:
