Only experience was of a JP piston in a Matchless on a friends bike, it siezed in 20 yds due to machining being not finished properly. The relief area around the rings was not cut at all and the rings also had no give to them, first bit of heat and the piston siezed, piston was also a lot heavier than the original, seems one of their blanks can be used for lots of different pistons and in some lots of meat is left on. I would go for hepolites eg AE pistons or Cycle Craft, if using Cycle Craft pistons do not use their rings but use Hepolites.
Joined: 01 Oct 2007 Posts: 34 Location: Mandurah, Western Australia
Posted: Mon Jun 30, 2008 4:03 pm Post subject:
Hi, Kommando.
Thanks for that information. It seems that these pistons are not up to scratch!!!! judging from the lack of respone that I have recieved.
I please, would also like to hear any opinions of anybody, who has installed these Pistons in 850 commandos,
Perhaps they are just crap and are a waste of money?????
Posted: Wed Jul 02, 2008 4:32 am Post subject: jp pistons
I installed jp pistons on my 750 commando. I have not started the motor up yet, but I noticed that when I went to fit the barrels I had to take the barrel off and pistons, install the pistons then reconnect them to the rods. Usually rings have a taper on the top, these did not. Am I in for a nightmare?
Joined: 01 Oct 2007 Posts: 34 Location: Mandurah, Western Australia
Posted: Wed Jul 02, 2008 7:23 pm Post subject:
Hi mcns,
I have not installed this brand of pistons in my bike.
However, I need to buy new pistons kits for my 850, and have been trying to do some research or get first hand opinions about these JP Pistons.
I have not had a lot of luck in doing so!
It would be great if there are other Commando riders out there who could share their experience with us about these pistons and rings.
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At the end of 1967 the Norton Commando was announced.
The Norton Commando was greeted with a certain amount of scepticism because on first sight the commando appeared to comprise of the old Norton Dominator twin cylinder engine mounted at an inclined angle in a set of new cylinder parts.
It was not realized that the new Norton Commando Isolastic method of engine suspension damped out all engine vibration and produced a machine which had uncanny smoothness for a vertical twin. In due course the critics were silenced and the Norton Commando had the distinction of being regarded as the first of todays so called superbikes. There can be little doubt that the original design concept of the Norton Commando has proved correct, since comparatively few modifications of any real consequence have been made since production commenced during 1968.
Now nearly 40 years later Norton Commando riders like us are a breed of our own, and as far as we are concerned its still more fun to go for a blat on the old Norton Commando, and fast. As a Norton Commando owner and enthusiast, my goal here is to promote and give credit to those who keep the Norton name going.
It is more deserving to give credit to the Commando itself, for after all these years it continues to be respected. The original Commando designers like John Favill are those who deserve the credit for developing this incredible motorcycle.
The Norton Commando Roadster and Interstate of the late seventies, never died. Although the Norton Villiers factory dispersed the tradition lived on. Today Kenny Dreer in the USA is developing the new 952 CC Norton. What a great looking bike this is, and its engineering is still based on the original layout. It will be interesting to see how the new 952CC Norton does in todays tough motorcycle market. One thing is for sure, I would own one if I could afford it.
