1948 cylinder spacer

[Douglas Campbell]

Has anyone experience of running the G80 with and without the spacer under the cylinder?
I am undecided wether to fit it or not and would appreciate any feedback on the difference it made.

[Samuel]

My '49 G80 has been without the 'spacer' under the cylinder for last 16 years or so.
It has a good feeling to the engine, cracking on well and feeling peppy - when it is running.
My problem is with the Pre-Monoblock (new 289B from Amal Carbs a few years ago)
https://amalcarb.co.uk/carburettor-for- ... 80-g9.html
It just does not behave vey well for me and I end up kicking over for minutes at a time with no joy

[SPRIDDLER]

Welcome to the club and forums!

I don't know how familiar you are with old bikes but the spacer was supplied to reduce the compression ratio, making the engine happier with the the low octane post-war 'Pool' petrol.
I've no personal experience of an engine with the spacer but I guess that by lowering the comp ratio it would be a bit easier to kickstart at the expense of a bit of engine output power.

An indication of the fittings for the pushrod tubes with and without the spacer depends upon the engine number. See page 10 in the factory Spares List for your bike here:

http://archives.jampot.dk/book/Spares_l ... st_CL8.pdf

Have you found the Owners Manual and the Workshop Manual for your bike? If not, they are in the archives here under 'books'......

http://archives.jampot.dk/

[clive]

Has anyone experience of running the G80 with and without the spacer under the cylinder?
I am undecided wether to fit it or not and would appreciate any feedback on the difference it made.

A small point but if you are intending to replace a worn barrel you will need to hone out the ridge that is at the top. Personally I took them out on the bike Sam now has many years before the 16 years he quotes. Leaving it in just means less compression/performance.

[Douglas Campbell]

Thanks for the replies. I have got all the info from the archives and very useful it is.
Mine currently is set up without the spacer. I will probably leave it as is.
Cheers
Doug