English French German Italian Spanish

J S Motorsport - lightweight pistons

Submitted by paul_carcary on Fri, 20/05/2022
Forums
Commando

Hi

I've been doing too much reading and not enough actual work (i like to call it research) prior to embarking on 2 x commando projects (my current matching numbers 750 S is just about finished, picture attached)

I came across JS Motorsport in the USA and Jim Schmidt (the JS) who has a bunch of what appear very well engineered and thought out mods and parts, particularly the lightweight short pistons and long conrods, with a fair amount of good feedback and success.

with a rebuild of a "project bike" inevitably going to require engine overhaul, and old rods being a critical part, it seems a sensible mod anyway.

does anyone here have any experience with any of Jim's parts, or know of an equally well engineered UK sourced or supplied alternative ?

I'm all for original things, but 50 years of time and experimenting cant help but offer improved reliability and performance

thanks for reading

Attachments
left side 1.jpg

Submitted by mark_savage on Sat, 21/05/2022

Permalink

I've got the lightweight Carillo rods and JE pistons from Jim Shmidt in my 750.  Not for racing or anything like that but for longevity. I chose the medium compression pistons over the higher compression version.  The combination of the pair were lighter than the originals or at least lighter than the rods and GPM pistons that I took out and the items weighed exactly the same as each other, again, unlike the items I took out which differed quite a bit to each other which must be better for less vibration.

I must admit to being seduced by Jim's blurb but I've not regretted buying them. 

 

Submitted by peter_shand on Sat, 21/05/2022

Permalink

I bought some of Jim's JE pistons (81mm versions) to go in the Merlin DOHC engine along with his Carrillo rods (that i already had) Had to get them from Jim as he got the top of the pistons machined for the four valve per cylinder layout. He had problems with delays in delivery from JE (i was waiting months) Best email him with your requirements and ask about delays etc.    

Hi Peter

thanks for the reply, yes, I have had an email conversation already

the vagrancies of international deliveries are a well trodden path for me with other bike projects relying heavily on USA imports (ouch those import duties too!)

looks like I'm sold for internals

Submitted by jan_nelder on Tue, 24/05/2022

Permalink

I fitted the pistons ( standard compression)and rods, road cam and his lightweight followers and valves and springs to a mk 3 Motor. No complaints, and delivery in 2015 was fine, although import duty had to be paid of course. Since then, piston skirts are now coated.

 



© 2024 Norton Owners Club Website by 2Toucans