Hello
I have just started stripping down my 1961 G12 CSR to try and cure some oil leaks. The bike came with receipts for work that had been done in the past but there and two list pistons with different compression ratios. With the heads off I can see the part numbers on the pistons and these are JP0633 + 0.020 HJ. I'm hoping that these are the 8.5:1 type. Can anyone confirm this?
Thanks
CAB
- New Users
- Board index Help G12 / AJS Model 31
-
- It is currently Fri Apr 26, 2024 4:20 am
- All times are UTC+01:00
Compression ratio of JP0633 + 0.020 Pistons
Information relating to the Matchless G12 or AJS Model 31 650cc twin
-
- Member
- Posts: 116
- Joined: Thu Jul 09, 2009 9:10 pm
- Location: CORNWALL UK
Return to “G12 / AJS Model 31”
Jump to
- Public Forums
- ↳ General Topics
- ↳ Modern AJS
- ↳ Help
- ↳ Frequent Questions
- ↳ Recommendations
- ↳ Where are they now?
- ↳ News Items
- Help
- ↳ G2 / Model 14
- ↳ G3 / Model 16
- ↳ G5 / Model 8
- ↳ G80 / Model 18
- ↳ G80 Harris
- ↳ G9 / AJS Model 20
- ↳ G11 / AJS Model 30
- ↳ G12 / AJS Model 31
- ↳ G15 / AJS Model 33
- ↳ Competition / Racers
- ↳ Prewar
- ↳ Two Strokes
- ↳ Pre-War
- ↳ Post-War Classic
- ↳ G2 / Model 14
- ↳ G3 / Model 16
- ↳ G5 / Model 8
- ↳ G80 / Model 18 / Harris
- ↳ G9 / Model 20
- ↳ G11 / Model 30
- ↳ G12 / Model 31
- ↳ G15 / Model 33
- ↳ Modern AJS
- Sections
- ↳ Bristol
- ↳ Cheshire and North Wales
- ↳ Chiltern
- ↳ East Berkshire
- ↳ East London and Essex
- ↳ East Midlands
- ↳ East Suffolk
- ↳ East Yorkshire
- ↳ Fenrunners
- ↳ Hampshire
- ↳ Heart of England
- ↳ Kent
- ↳ North East
- ↳ Notts and Derby
- ↳ Oxford
- ↳ Poachers
- ↳ Surrey
- ↳ Sussex
- ↳ Wey Valley
- ↳ Worcester
- ↳ France