BSA Owners' Club Workshop Discussions

The BSA Workshop => Bantam - pre 1973 => Topic started by: A10 JWO on 01 Apr, 2018, 15:10

Title: D7 Restoration
Post by: A10 JWO on 01 Apr, 2018, 15:10
I have been offered a D7 in running order for £750. Not bad. It will need restoring but I am worried about the cost. I have spent a fortune on a 650 I have nearly finished. I will get some money back if I sold it. However if I were to fit new rims, tyres and a respray the Bantam will it be worth the effort. I only buy these bikes to rescue them but don't want to bang my head on a brick wall. You lads must have some good advice on the section, thanks.
Title: Re: D7 Restoration
Post by: AWJDThumper on 02 Apr, 2018, 08:19
I have just started the restoration of a D14 and know exactly what it will cost to finish the project - this will basically be more or less the same as that of any of the other single cylinder BSA's I've restored. Since the D14 will be a full restoration, it will almost certainly cost me more to restore in this way than it will be worth when finished if you also take into account the initial purchase price. However, I need to add a Bantam to my collection of BSA's and so I'm happy to bear the cost.
Title: Re: D7 Restoration
Post by: A10 JWO on 04 Apr, 2018, 14:43
Hi Thumper, will test ride the D7 tomorrow if its not peeing down. Found a lock up at my mates mums where my wife can't see it till 2019.  ::)
Title: Re: D7 Restoration
Post by: AWJDThumper on 04 Apr, 2018, 15:43
Fortunately, my wife gave up trying to stop me buying motor bikes a long time ago providing I don't encroach on her garden. :)
Title: Re: D7 Restoration
Post by: A10 JWO on 04 Apr, 2018, 15:49
Do the little later four speed engines interchange with these smaller models ? Thanks. I seem to remember some of those were highly tuned years ago.
Title: Re: D7 Restoration
Post by: JulianS on 04 Apr, 2018, 16:10
Yes you can replace a 3 speed engine with a 4 speed engine.

Wiring different between flywheel magneto models and D10 and later models.

The best engines were the last, the B175 units. The D14/4 did have a weakness in the rivitted on crankshaft compression plates with could let go and wreck your engine. The factory recommend replace them with latest type.
Title: Re: D7 Restoration
Post by: A10 JWO on 04 Apr, 2018, 17:34
Thanks Julian.
Title: Re: D7 Restoration
Post by: A10 JWO on 05 Apr, 2018, 16:31
The Bantam has joined my family, more questions at a later date. thanks.
Title: Re: D7 Restoration
Post by: AWJDThumper on 07 Apr, 2018, 11:07
Hope you enjoy restoring your Bantam. Having fun restoring my D14 engine at the moment - I was brought up working on these two strokes but am having to re-learn the art. The main thing I notice is how fragile the die cast engine casings are compared with the normal sand cast 4-strokes ones found in other BSA's.
Title: Re: D7 Restoration
Post by: A10 JWO on 08 Apr, 2018, 17:19
I too will have to re-learn the 2 stroke art. I used to tune Lambrettas to 21 BHP years ago, 30 mm carb and expansion boxes. Still have an SX 200 in the back of the garage. Wish I was young again.  ???