Solex carb - adjusting fuel mix

Singles, twins and fours.
User avatar
Akumar
Posts: 73
Joined: Fri Aug 23, 2013 10:10 pm
Location: Minneapolis, USA
Contact:

Solex carb - adjusting fuel mix

Postby Akumar » Mon May 08, 2017 5:14 am

Dear fellow enthusiasts,

This is regarding my 1948 framed Square with a 1937 engine. I was checking the spark plugs and noticed signs of a significantly lean fuel mix. How does one adjust fuel mix on a Solex?

Thank you.

Kumar
48' SQ4, 53' VB, 51' NH

stuart.wilby
Posts: 27
Joined: Mon Dec 30, 2013 5:21 pm
Location: Wakefield
Contact:

Re: Solex carb - adjusting fuel mix

Postby stuart.wilby » Sat May 13, 2017 7:46 am

More fuel,up one size of jet as described in operators manual.unless you have the following,
It could be the throttle butterfly bearings are leaking air if worn, try Viton o rings I sourced mine at simplybearings.co.uk they have these high temp seals in all sizes, you will need to groove the shaft on a lathe, be careful, do a test run on a piece of stock bar before the original is machined try it in the body, if it's correct it will try to suck your finger in the hole (piston like).
Check the butterfly blade sits nicely in the body, if you have had it apart, is it back the right way round ? there will be wear in the contact areas here, good to get it back as it was, bedded in from previous service.
David Jones supplies spares, refurbished and exchange I believe here in the UK, a good supplier and fount of knowledge on these great instrument.
1948 4G Square.

User avatar
Akumar
Posts: 73
Joined: Fri Aug 23, 2013 10:10 pm
Location: Minneapolis, USA
Contact:

Re: Solex carb - adjusting fuel mix

Postby Akumar » Fri May 19, 2017 4:01 am

Hi Stuart,

Thank you. I have ordered a no. 25 jet from David. I will update after it has been installed. I also wanted to point out that the rear left side spark plug definitely seems to be "darker". I am not sure if the valve guide is leaking oil or if the rings are suspect.

Kumar
48' SQ4, 53' VB, 51' NH

User avatar
chris.shearwood
Holder of a Nylon Anorak
Holder of a Nylon Anorak
Posts: 268
Joined: Mon Feb 28, 2011 5:28 pm
Location: Sutton, Quebec, Canada
Contact:

Re: Solex carb - adjusting fuel mix

Postby chris.shearwood » Fri May 19, 2017 11:55 am

Hi Kumar,
Don`t forget to make sure the carb/rocker box joint isn't leaking air into the inlet tract.
1946 4G, 1950 NG and 1951 VH


Return to “Four stroke”

Who is online

Users browsing this forum: No registered users and 3 guests