Matchless G3LS 1953 questions

Information relating to the Matchless G3 or AJS Model 16 350cc Heavyweight
Posts: 19
Joined: Sat Oct 07, 2017 3:13 pm

Re: Matchless G3LS 1953 questions

Postby Jonny Astro » Mon Aug 20, 2018 2:28 pm

Me again!

My 1953 G3LS is running really nicely, especially since fitting the monobloc carb. Just approaching 500 miles since it's rebuild by the previous owner, so I thought I'd give it the once over - change the oil, check the timing, etc. Questions:

1/ Do I need to drain the sump or would it be OK to just change the oil in the tank?

2/ Will I need to use a new primary case seal after checking the chain or are they re-useable?

3/ I gather that ignition timing is 7/16" or 1/2" BTDC, but given that the spark plug hole, through which I will poke my depth gauge, is at about 45 degrees to the stroke axis, do I need to do some trigonometry or is that measurement taking the angle into account?


Posts: 1050
Joined: Mon Mar 24, 2014 5:44 pm
Location: Aberdeenshire

Re: Matchless G3LS 1953 questions

Postby Mick D » Mon Aug 20, 2018 3:47 pm


1/ I'd drain the sump too - it will allow you to ascertain there are no horrors lurking - if you see any metallic debris in the sump oil it would be cause for further investigation.

2/ I'd only check / adjust the chain tension - doesn't your chain case have an inspection port to facilitate this? If this is the gasket to which you refer, I'd have one standing by but have a go at re-using the original.

3/ The dimensions are 'vertical' as I understand - just rest your depth gauge on the inboard side of the plug hole and keep it vertical-ish and you'll be OK.

Regards Mick

User avatar
Posts: 443
Joined: Mon May 01, 2017 6:32 pm
Location: Lancashire

Re: Matchless G3LS 1953 questions

Postby spookefoote1956 » Fri Sep 07, 2018 6:51 pm

Try cleaning the carb with some wynns carb cleaner. Sorted mine out a treat.
हरे कृष्ण हरे कृष्ण
Hail Joe Lucas ............ Prince of Darkness!


Return to G3 / Model 16

Who is online

Users browsing this forum: No registered users and 6 guests