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Title: Bsa b31 dynamo
Post by: 750rideruk on 26 Oct, 2021, 15:13

Please can any of you fine people tell me the diameter of a B31 dynamo. I am building a bike but want to leave off the lights. Currently have an alloy tube in place of the dynamo but is too big to allow me to fit the float bowl behind the carb. Many thanks in anticipation of your replies

Title: Re: Bsa b31 dynamo
Post by: Derek996 on 26 Oct, 2021, 16:00

Title: Re: Bsa b31 dynamo
Post by: kenif on 27 Nov, 2021, 09:12

Hi,
Lucas E3L are 76mm diameter.. Hope this helps..

Title: Re: Bsa b31 dynamo
Post by: leon bee on 28 Nov, 2021, 18:58

I have a 650 Triumph piston holding my magneto down.

Title: Re: Bsa b31 dynamo
Post by: JulianS on 29 Nov, 2021, 09:54

The 3 in E3L is for 3 inch diameter body.

The E for eccentrically mounted armature.

L for long body.

If there is an M it indicates it was magdyno mounted.

Title: Re: Bsa b31 dynamo
Post by: 750rideruk on 30 Nov, 2021, 14:08

Thanks Leon Bee. Good idea. which i shall steal.

Title: Re: Bsa b31 dynamo
Post by: leon bee on 01 Dec, 2021, 19:25

I even shined the old, used piston up a bit before installation.

BSA Owners' Club Workshop Discussions

The BSA Workshop => Singles => Topic started by: 750rideruk on 26 Oct, 2021, 15:13