| Diagram | Fig. 4 — Engine: Contact Breaker, Timing Cover, Oil Pump, Oil Pressure Relief Valve · ref 28 |
| Subsystem | engine bottom |
| Listed in parts books | 1975 |
Norton Piston
A small piston used in the oil pressure relief valve assembly on Norton engines.
This 06-7540 is listed simply as a piston, and the catalog figure it shows up under is the contact breaker, timing cover, oil pump, and oil pressure relief valve group. Read together, that points to this being the small piston inside the oil pressure relief valve assembly, not a main engine piston - the relief valve uses a spring-loaded piston to bleed off excess oil pressure and keep the lubrication system in check.
Read more
Our record on this one is thin, just the single catalog listing tied to that assembly. It's a Norton part per our records, and the one appearance we have places it in the 1975 model year.
Given how little detail we have, if you're chasing down an oil pressure relief valve piston for a rebuild, give us a call and we'll confirm fitment before you order.
Sorry if we got something wrong here. If you think this information isn't correct, .