BSA Owners' Club Forum

The BSA Workshop => Singles => Topic started by: Barrieh on 07 September, 2021, 18:41:30

Title: Amal concentric carb - BSA M33 + Aspen
Post by: Barrieh on 07 September, 2021, 18:41:30
Hi,

Just a quick note that I took the plunge and fitted a MK1 Premier Amal concentric carb 28MM with a 19cc idle jet, 260 main jet, with the needle value middle slot. Seems to work really well and idles really well. Overall runs very nice and kind of fits in.

I am running this on ASPEN 4 stroke petrol and I have to say its so much less smelly and seems to go very well.

Keen to hear other peoples thoughts and experiences.

Hamish
Title: Re: Amal concentric carb - BSA M33 + Aspen
Post by: Mike40M on 07 September, 2021, 20:49:34
On Aspen 4. Ethanol free. 95 octane. Can be in tank and carburettor for long periods. Started a Norton WD16H second kick. Forgot to retard ignition on first kick. Had stood in barn for 5 years unused with Aspen in it.
Seems to have same jetting on Aspen as on E0 or E5.
Title: Re: Amal concentric carb - BSA M33 + Aspen
Post by: DAVE BRADY on 07 September, 2021, 22:34:59
Hi,

About 20 for 5 litres.  Is it feasible to use this other than for very small annual mileages? 

Dave.
Title: Re: Amal concentric carb - BSA M33 + Aspen
Post by: Barrieh on 08 September, 2021, 16:31:24
Dave, I bought a 25 litre drum for about 80. It is expensive and if you are doing a fair mileage every few weeks Super Unleaded E5 will be fine, but I do more sporadic runs which means the bike can sit for a month before another big run.

To be perfectly honest it was the smell of E5 / 10 that really put me off using it. Its paint stripper smell is just too much and it quickly goes yellow after a couple of weeks. I am sure technically it will be fine but the smell in the garage was making me feel ill.

What I can say is that Aspen runs the engine nice and cool, it doesnt smell, its a very clean fuel e.g. far less nasty stuff in it... but it comes at a cost.

I have no other vices in life, dont smoke, gamble.... occasional beer etc... so why not. As my late father reminded me, there are no pockets in a shroud!
Title: Re: Amal concentric carb - BSA M33 + Aspen
Post by: DAVE BRADY on 08 September, 2021, 18:41:34
Hi,

I still have bit of E5 in our bikes but next week we will probably run some E10 through.  It will be interesting to see if there is a noticeable difference.  A couple of times in Europe we had to use E10 as the filling stations only had E10 and Derv.  The bikes ran OK but I suspect that a couple of degrees less advance would have been beneficial.  We will run our bikes with no changes for a tank full and then see if a slight change to the timing helps or not.

Dave.