Retrofit Amal Premier pilot jets? (2016)

Joined
May 20, 2013
Messages
12
I've removed the pilot circuit blanking plugs on my Amal 930s and pressed out the .016" pilot bushings, tapping the blanking plug passages 2BA.
Is it possible to fit the Amal Premier pilot jets through these former blanking plug orifices?
Would one choose an .015, a .017, or a .019" for today's fuel?
If not possible, something else that could improve on the gol' darn .016 bushing?
App is a '67 RE Interceptor.
Thanks, and apologies for possibly dumbly lobbing a "oil thread" question out!
Cheers,
gl
 

Jerry Doe

Admin
Joined
May 21, 2003
Messages
1,487
Country flag
The Amal premiers come with a #17 pilot jet. I find these too lean with peashooters and use a #19.
I am not sure about the first part of the question. Sounds a bit sketchy.

Cheers
 
Joined
Feb 10, 2009
Messages
1,929
Country flag
grayluders said:
App is a '67 RE Interceptor.
That makes it unlikely anyone knows an ideal size for an alternative pilot jet.

But as you are not happy with the standard size, is that because you think it is too big or too small? Is it passing too much fuel or not enough?
 
Joined
May 20, 2013
Messages
12
Triton Thrasher said:
grayluders said:
App is a '67 RE Interceptor.
That makes it unlikely anyone knows an ideal size for an alternative pilot jet.

But as you are not happy with the standard size, is that because you think it is too big or too small? Is it passing too much fuel or not enough?
Thanks - real issue is viability of using Premier external pilot jets in lieu of the pressed-in bushing.
Just hypothesizing that, given that original pressed-in bushing is a wimpy .016", and the premier jets range considerably larger, that there is an opportunity to compensate for today's "different" fuel.
gl
(who has a Combat fitted with a 34mm Mikuni, thank you)
 
Joined
Apr 29, 2009
Messages
1,164
Country flag
Instead of switching to the #19 couldn't you just turn the air screw in a little bit?
 
Joined
Dec 2, 2012
Messages
881
Country flag
My air screws (with premieres) are three quarters of a turn out. I wondered why as the bike will not idle or start on the more normal one an half turn (starting point) now I can see why.
 

RoadScholar

VIP MEMBER
Joined
Dec 28, 2008
Messages
1,461
Country flag
I have a '67 RE Mk1a that came with a new set of still-in-the-box 930s that were jetted according to the work shop manual; I have the air screws out about 2 turns and it runs fine with 93 R+M/2 E10 (sign on pump says MAY CONTAIN up to 10%).

The Premier pilot jets won't fit, but, probably, could be made to, the architecture is essentially the same. New Amal concentrics are relative cheap and function very well if you add a chrome sides, or just purchase the Premiers and go worry about something else...

If you pursue the implementation of the Premier pilot jets into your 930s, please add some pictures, and best wishes.
 
Joined
Sep 23, 2013
Messages
73
htown16 said:
Instead of switching to the #19 couldn't you just turn the air screw in a little bit?
I have the same question. I'm running peashooters with new Amal Premiers + K&N on my MkIII and getting midrange popping. 1.5 turns out on the air screws.
 
Joined
Oct 31, 2009
Messages
5,191
Country flag
ag12680 said:
htown16 said:
Instead of switching to the #19 couldn't you just turn the air screw in a little bit?
I have the same question. I'm running peashooters with new Amal Premiers + K&N on my MkIII and getting midrange popping. 1.5 turns out on the air screws.
Yes you can but you can only go so far to where air screw position doesn't make a difference and the jet will need to be sized. If you are just too darn lean you could screw it in all the way and it won't respond of if too rich and/or blocked you could unscrew it completely without change.
 

Nater_Potater

VIP MEMBER
Joined
Apr 7, 2013
Messages
1,327
Country flag
htown16 said:
Instead of switching to the #19 couldn't you just turn the air screw in a little bit?
Okay for idle, but the pilot jet affects operation into slide cutaway/needle realm, so you're primarily running on the pilot jet during a steady-throttle cruise. This has a direct bearing on fuel mileage, also.

Nathan
 
Joined
Feb 10, 2009
Messages
1,929
Country flag
ag12680 said:
htown16 said:
Instead of switching to the #19 couldn't you just turn the air screw in a little bit?
I have the same question. I'm running peashooters with new Amal Premiers + K&N on my MkIII and getting midrange popping. 1.5 turns out on the air screws.

How far open is the throttle in your "midrange?"
 

Jerry Doe

Admin
Joined
May 21, 2003
Messages
1,487
Country flag
I have Toga peashooters on a Standard MK3. I had to put #19 pilots in and raise needle 1 notch. I cannot remember what size mains I ended up with...
 
Joined
Apr 29, 2009
Messages
1,164
Country flag
I've put on two sets of Premiers and all four had fuel levels more than .27 below the float bowl top, Amal's recommended minimum. This is measured with a u-tube at the middle of the carb. If you suspect leaness this is another variable to check.
 
Joined
May 20, 2013
Messages
12
RoadScholar said:
I have a '67 RE Mk1a that came with a new set of still-in-the-box 930s that were jetted according to the work shop manual; I have the air screws out about 2 turns and it runs fine with 93 R+M/2 E10 (sign on pump says MAY CONTAIN up to 10%).

The Premier pilot jets won't fit, but, probably, could be made to, the architecture is essentially the same. New Amal concentrics are relative cheap and function very well if you add a chrome sides, or just purchase the Premiers and go worry about something else...

If you pursue the implementation of the Premier pilot jets into your 930s, please add some pictures, and best wishes.
After no response from Burlen or several other chat groups I'd posted to, until your message, I ordered a pair of .019 Premier jets, and a pair of earlier Concentric .025 jets, the ones that thread in to the front flange transfer port from the float bowl.
So we'll see what, if anything, can be made to work.
Did find on an archived Triumph chat group discussion that the earlier front idle jets may not work if the carb bodies were originally for two versus four-stroke applications - why we don't know, presumably something in the transfer passages.
At the very least, the idiot pressed-in bushings can always be reinserted, and I'll have cut-off air screws threaded in to the former plugged passages for cleaning.
Will report back later.
Cheers,
gl
 
Joined
May 7, 2005
Messages
4,054
Country flag
The earlier 25 marked pilot jets are 17 thou, and cleaned out using a 16 thou drill.
 
Joined
Feb 13, 2013
Messages
505
Country flag
I see Old Britt's sell the elusive Amal Premier pilot jets in various sizes. $25 each!
A little precision drill bit is pretty cheap. I think I'd try drilling my removable jets slightly larger before I'd pay 50 bucks for 2 new ones, but then I'm pretty cheap.
What could possibly go wrong?
go wrong?
o wrong?
wrong?
wrong?
rong?

I have 2 new (untested) 930 Premiers on my Atlas so I may put this to the test.

https://www.oldbritts.com/ob_1830.htm
 
Joined
May 20, 2013
Messages
12
mschmitz57 said:
I see Old Britt's sell the elusive Amal Premier pilot jets in various sizes. $25 each!
A little precision drill bit is pretty cheap. I think I'd try drilling lean my jets before I'd pay 50 bucks for 2 new ones, but then I'm pretty cheap.
What could possibly go wrong?
go wrong?
o wrong?
wrong?
wrong?
rong?

I have 2 new (untested) 930 Premiers on my Atlas so I may put this to the test.

https://www.oldbritts.com/ob_1830.htm
Here's a link to a Triumphrat discussion, in which Phil Beresford of Burlen explains quite a bit, and includes a cutaway photo
http://www.triumphrat.net/classic-vinta ... ost2957057

I separately just heard from Mr. Beresford, who wrote: "The Premier carburetter bodies are machined differently to provide a seat for the taper of the Premier Pilot Jet."
This taper shows in the photo mentioned above.

Unless I can establish a good taper for a Premier jet (lapping with an old pilot bushing brazed to a spindle?), looking more like trying a jet threaded at the front flange transfer port makes more practical sense.
gl
 
Joined
Sep 23, 2013
Messages
73
By midrange I mean 2-3K RPM. I have 260 mains and moved the needle all the way up (clip in bottom notch). Still not sure why the pilot jet can't be addressed with the air screw.

Almost have the brakes done so I can actually ride and see what the motor does under load.

Thanks guys,

Andy --
 
Top