Ring gap please

Anything related to Lambrettas... ask tech questions, post helpful info, or just read and learn.
sydduckett
registered user
Posts: 1900
Joined: Wed Jan 14, 2009 12:21 am
Contact:

Can someone let me know te ring gap for an rb20, i think it might be .5 but im not sure.

Thanks
sef
User avatar
jonashford
registered user
Posts: 445
Joined: Wed Oct 20, 2010 4:47 pm
Main scooter: Lambretta SX RB235
Location: GRIMSBY
Contact:

I think it's on afs site
sydduckett
registered user
Posts: 1900
Joined: Wed Jan 14, 2009 12:21 am
Contact:

jonashford wrote:I think it's on afs site

had a look on AF site but couldnt find this info. anyone know or point me in the right direction

ta
rosscla
registered user
Posts: 4823
Joined: Tue Oct 25, 2011 9:50 pm
Main scooter: Lambretta
Location: Lanarkshire
Contact:

According to the fitting instructions 0.6mm (0.0025") is the gap at which the rings should be replaced

http://www.afrayspeed.co.uk/index.php?page=Per_rb22
"Our dilemma is that we hate change and love it at the same time; what we really want is for things to remain the same but get better."
sydduckett
registered user
Posts: 1900
Joined: Wed Jan 14, 2009 12:21 am
Contact:

rosscla wrote:According to the fitting instructions 0.6mm (0.0025") is the gap at which the rings should be replaced

http://www.afrayspeed.co.uk/index.php?page=Per_rb22

Thanks for that, looked at that page but couldnt see it for the life of me. New Rings are giving me .5. I guess thats near enough.... :D
rosscla
registered user
Posts: 4823
Joined: Tue Oct 25, 2011 9:50 pm
Main scooter: Lambretta
Location: Lanarkshire
Contact:

Just so it's clear that is the gap they recommend REPLACING the rings at.
"Our dilemma is that we hate change and love it at the same time; what we really want is for things to remain the same but get better."
Muppet
registered user
Posts: 1279
Joined: Thu Sep 16, 2010 9:54 pm
Main scooter: SX 150 running in

0.3 is good but never less than 0.2,

muppet,
C’est la vie
User avatar
chris2470
registered user
Posts: 135
Joined: Tue Apr 07, 2009 8:52 pm
Location: Cambridge
Contact:

An easy way to remember is approx 0.1mm per Inch/25mm of bore.
Best Regards

Chris
sydduckett
registered user
Posts: 1900
Joined: Wed Jan 14, 2009 12:21 am
Contact:

Muppet wrote:0.3 is good but never less than 0.2,

muppet,
I replaced the AF piston that came with the kit with a DT175/blaster piston. Bloke was shutting down his motorbike shop and had a box full of nos pistons that he had knocking about since the 80,s he pulled 2 of these out and said these should fit which they did. Both me and my mate stuck in our rbs to see what they were like and both bikes went better than before so we kept them in. Only cost a £10 as well.... :D

Anyways when we went to replace the rings the gap was just under 2.0, with the new rings the gap is back down to 0.5
Im guessing that as its no longer an AF barrel this would explain it not being 0.3 with new rings. Thought it was a tad low on compresion.... :D
Post Reply Previous topicNext topic
  • Information
  • Who is online

    Users browsing this forum: Ahrefs [Bot], Google [Bot] and 37 guests