what carburetor for 1959 super rocket

[chaterlea25]

Hi Peter,

Amal 1 1/8" bore Looks like a 290 or 250 jet as per spec 389/31 or a 48 which run 3.5 slide with a 30 pilot it take your pick time

Those are the sizes with air filter
400 or 420 without

Modern fuel has a different specific gravity to what was recommended back then so some experimentation is mostly required

HTH
John

[peter small]

Im using a Pan cake filter and its jetted 240 as a matter of interest

[peter small]

Have the Amal 389 1 1/8 fitted started up no problem ticks over like a good one had to lower the needle as it was far to rich.
Used a colortune to check the mixture burn and it seems ok although it does hesitate when you blip the throttle.
I would have to adjust the settings when i fit a filter.

if you accelerate smoothly it is fine and it feels like more power is being developed, haven't road tested as the weather at the moment is rubbish.
The old pancake filter doesn't fit anymore so do i buy a new Pancake or go for the original anyone have a view on it

Thanks for your input great site

Pete

[peter small]

Been out for a 50 mile run at a constant 50 mph and the plug colour is spot on.
starts OK when hot so the  Tufnol spacer has done the trick.
Much more responsive with the bigger carb
Cant really check main jet as the motor has a few more miles before it run in



 

[Viking]

If you have a late SR head, get the 389.

If everything is set correct, you will get a crisp throttle responce with the correct carb:

http://amalcarb.co.uk/cf/vehicle/list/?manufacturer=B.S.A&vehicle=A10+Super+Rocket+%28Export%29

[a101960]

Just for the record my bike is fitted with a large valve head. Carb is a 389 bore 1 and 5/32" and the settings are: Slide 3, main jet 420, pilot 25, and 106 needle set on second position from the top. It goes very well!
John

[peter small]

Bike  was going very well with the new carb running in progressing been up to a staggering 60 mph without a hitch.
Now its the turn of the 6 spring clutch to get binned.
But that`s another story.

Amazing what you have to do to keep them on the road.

Pete

[Topdad]

yes indeedy , surprised you'd kept it so long , best of luck.

[Rocket Racer]

Bike  was going very well with the new carb running in progressing been up to a staggering 60 mph without a hitch.

Pete

According to the literature of the day (Eddie Dow), safe continous rpm is 6800 and through the gears to 7200.
So 60mph shouldn't be too hard even with the sidecar and caravan attached   

[peter small]

Hi
The engine is still being run in that`s why i haven't gone over 60 mph.
 if i blow it up,Will Eddie Dow be round to fix it NOT.


Pete

[Rocket Racer]

It sounds like your new carb is giving it some performance potential  but if you're still running in a bit of restraint initially won't hurt.