LCGB Forums

Hi could someone give me some ball park jetting figures for a mk2 Amal please, st5/6 tuned 225 with fresco, and also how do people usually block off the power jet? I heard you just don't fit the rubber around the bellmouth? Is that right?!

Cheers....

Jetting off the old AF site, may get you in the ballpark

Picture from a few years ago when I run a MK2 concentric - pretty sure I only put the rubber band around ran OK,also the best induction noise of any carb.Like I say a few years ago so can't be 100% sure.

Hi

I can’t give you ballpark figures, but from what I can recall, power-jets were kind of in their infancy when I used that set up. I think you are right in that removal of the bell-mouth feed moulding did disable them. I can’t recall having to do anything else.

However, power-jets were de-rigueur on piston ported engines & not reed valve.

Looking @ the AF chart (posted above) those main jet sizes seem huge from what I have in my Amal jets stock, which would have been used on a barrel with a similar state of tune to your set-up.

Sorry I can’t help more….

Cheers davetomo and warkton, nice info

Someone else gave me this-

3 or 31/2 slide 40 /45 pilot 2d1 needle 300 to 350 main ,,,as a start point ,,,ans 307/308/309 attomizer ,if i remember correctly


So Iv got some idea now , Anyone else got any figures... The more opinions the better, will get this dynod when it's run in but till then....
Cheers......

Those AF figures are for non PJ.

PJ + MJ should roughly equal those figures.

Mj?

Main Jet

Deh! Taxi for Nobby....Cheers!!

Asked Paul yet? He put a lot of time and effort into testing and adjusting his on his iron 238.

Word of warning... you'll get a lot of different answers from a lot of different people, even with this old carb, e.g. when I was asking about jetting for a standard TS1 225, with a range of common pipes, I had combinations of 107 with 410 MJ up to 109 with 320 MJ and a range of 4, 3.5 and 3.0 slides. Even after decades of people trying to find a common set-up, advice varied wildly. One of the UK's top tuners stating, "I've never set a TS1 up with a 107! You'll want a 108 or 109."

Paul can give you his details and I've got mine from my iron 240 if you want them.

Adam

Could someone tell me if number 15 is the power jet blanking screw??, or any tips on blanking the power jet... Or how I find out what size jet the power jet is?...

Cheers....

Adam_Winstone wrote:Asked Paul yet? He put a lot of time and effort into testing and adjusting his on his iron 238.

Word of warning... you'll get a lot of different answers from a lot of different people, even with this old carb, e.g. when I was asking about jetting for a standard TS1 225, with a range of common pipes, I had combinations of 107 with 410 MJ up to 109 with 320 MJ and a range of 4, 3.5 and 3.0 slides. Even after decades of people trying to find a common set-up, advice varied wildly. One of the UK's top tuners stating, "I've never set a TS1 up with a 107! You'll want a 108 or 109."

Paul can give you his details and I've got mine from my iron 240 if you want them.

Adam

Forgot he was using a mk2 Amal!.... Will find out.... Ta!

Nobby wrote:Could someone tell me if number 15 is the power jet blanking screw??, or any tips on blanking the power jet... Or how I find out what size jet the power jet is?...

Cheers....

I think that part 2622/142 originally was for blanking the pilot jet,but it can probably do the job that you want (convert a PJ carb to non-PJ).
If you run without filter start with 108 needle jet minimum.

Two pics,they might help,might not,you need to do the opposite task.

Thanks dimitrios!, Iv ordered that jet blanker- £2 so it's not going to break the bank,