BritBike Forum logo
BritBike Sponsor BritBike Sponsor BritBike Sponsor
BritBike Sponsor

BritBike Sponsor

BritBike Sponsor
BritBike Sponsor BritBike Sponsor BritBike Sponsor
JWood Auctions JRC Engineering dealers JWood Auctions
Home | Sponsors, Newsletter | Regalia | Calendar | Bike Project | BritBike Museum | Spiders Cartoons, "OLD" BritBike Forum | DVD- Manuals & Parts books | BritBike Stickers & Decals
Upgrade to: Premium Membership | Premium Life Membership | Vendor Membership | Site Sponsor Membership
Member Spotlight
dyna92
dyna92
Pennsylvania
Posts: 22
Joined: June 2011
Show All Member Profiles 
Shout Box
Search eBay for motorcycle parts in following countries
Australia, Canada, France, Holland, Italy, United Kingdom, USA
Random Gallery photo
Who's Online Now
33 registered members (Al Eckstadt), 182 guests, and 359 spiders.
Key: Admin, Global Mod, Mod
Newest Members
Dan1818, Konaflyer, Begbie, Andrew Fallo, Zack Banks
10419 Registered Users
Top Posters(30 Days)
btour 87
Rohan 78
reverb 75
Triless 73
Popular Topics(Views)
713,220 mail-order LSR
Forum Statistics
Forums34
Topics68,313
Posts665,105
Members10,419
Most Online3,995
Feb 13th, 2017
Like BritBike.com on Facebook

Previous Thread
Next Thread
Print Thread
Rate Thread
Page 8 of 8 1 2 3 4 5 6 7 8
Re: Tuning Your AMAL Carburetor [Re: ] #626955
11/23/15 2:42 pm
11/23/15 2:42 pm
Joined: May 2013
Posts: 5,004
Rotherham - S. Yorkshire
Allan Gill Offline

BritBike Forum member
Allan Gill  Offline

BritBike Forum member

Joined: May 2013
Posts: 5,004
Rotherham - S. Yorkshire
Originally Posted By needing
Hi John.
MM seems to be quite an astute person from his posts.
The fools I refer to are galoots that reference unseen AMAL documents yet never quite have an original thought.

I find your work very thorough and often refer to it. I also find it astounding that Mk1 AMALs have not been reverse engineered to improve the original design. The only improvements in 40+ years are to materials except for the adjustable pilot jet. While still 'good enough', I think they can be even better.
Ta.
Owen.


As all AMAL documentation is in the public domain I struggle to understand how it can be referred to as "unseen" documentation.

Not sure who your name calling here, but I'd be quite happy to be called a galoot, I've been called much vulgar things and this at least has a 19th century upper class ring to it.

There is a reason why the mk1 is what it is, it was designed to a brief - like any engineered item, it has to meet a criteria, some of those things was it had to be Concentric in design and it had to meet a certain cost. There is no reason to cry over a 100 carburettor when it wears out when it's alternative from Kehin or Mikuni ( which is a copy of the AMAL mk2) are more expensive to buy. There is a good reason why GP carbs are about 5x more to buy than a Concentric, there's also a good reason why many switch from earlier models to the mk1, the main reason is cost.

Without doing unnecessary mods to a mk1, they can be tuned to run on pretty much any vehicle, whether it be a jetting change or increasing the air bleed holes (or blanking them off) on the needle jet. This modification is one recognised by AMAL.

The graph above made me chuckle, it all means sweet FA until it is put into practice, there are also other areas of the induction, ignition, combustion and exhaust system which would have a far greater impact before this carb modification you have made starts to take effect.

But I admire your enthusiasm, you seem to have read a book or watched a video on this, bought some fancy equipment and feel like you've invented the wheel.
Yet you fail to understand that rpms is not relative to throttle position, any load or increased load will have a bearing on this, riding up a hill in top gear will mean a greater throttle position than if your in a different gear doing the same rpms or even the same gear but going down hill. The load has changed and so has throttle position to maintain the same rpms.

The biggest thing I've learned when being on these forums is you never know as much as you think you do (there are some exceptions to the rule) and even when you do, you need to listen to others opinions of the matter, there is always someone more knowledgable and when on here you don't have the first clue who your talking too.

There is a good reason why I haven't tried to redesign the Mk1 Concentric, if I want something better then I would buy a better instrument, however with a lot of road testing I am able to tune the mk1 to pull cleanly throughout the range and give good power and throttle response. On the occasions when I have not been able to tune out a flat spot or other issue, I've found adjusting the exhaust characteristics or cam timing has solved this problem. If you feel the urge to start hacking away at an instrument then you really don't have the first clue on how it works or how to tune it.

Reading this topic has given me and others a great sense of amusement but it's starting to get boring now.


beerchug
Support Your #1 BritBike Forum!

Check out British motorcycles for sale:
British Motorcycles on e-Bay UK, British motorcycles on e-Bay North America
Check out British motorcycles for sale:
British Motorcycles on e-Bay UK, British motorcycles on e-Bay North America
Re: Tuning Your AMAL Carburetor [Re: Morgan aka Admin] #626959
11/23/15 3:06 pm
11/23/15 3:06 pm
Joined: Mar 2005
Posts: 10,221
Boston, Massachusetts
J
John Healy Offline
BritBike Forum member
John Healy  Offline
BritBike Forum member
J

Joined: Mar 2005
Posts: 10,221
Boston, Massachusetts
Listen guys... this guy is talking trash. His last post convinces me he has no understanding of these carburetors.

May I quote, "The result: yep, at 3500 rpm my bike is just coming onto needle parallel and needle jet fuel flow." May I be so rude to suggest to Owen that the parallel portion of the needle (2.5 mm or 0.0984 inches) is in play from just off idle to approx. 1/3rd throttle (actual start position of the taper varies with position of needle clip) where the taper starts to influence the mixture.

In his picture he has the NP (Needle Parallel) starting to influencing the mixture at the point where it is starting to loose influence on the mixture. He has NT (Needle Taper) starting to influence the mixture at half throttle while it has already influenced the mixture near the point he has NP starting.

Any one who has had any experience with a throttle understands that throttle position at a given rpm varies with load. Load will vary with a lot of factors. The load riding into, or out of the wind, will give you different throttle openings for a given RPM. Throttle openings vs RPM will never be a constant as the factors that effect this change constantly. RPM is never used when tuning a carburetor. Throttle position is!
(Seems Allen and I were writing at the same time - sorry for the redundancy but this point is important)

Now he is now responding to people who haven't posted and thanking them for support.

Before you decide to contribute to this thread please go and look at the link above to Access Norton. All 30 pages of it that contains nearly 300 posts. You will know as much about his theories at the last post as you did at the first. In not one of them does he divulge anything that is not already common knowledge, references charts linked to AMAL that they never provided (one being a reference to Mikuni literature, not AMAL) or he makes claims with no factual data to substantiate his ramblings. It got so bizarre that the moderator locked the thread.

I am sure Owen is a wonderful chap. I would love to have a beer with him, but... and it is a big but keeping responding to this thread only increases the chances we will have another 30 page thread. And know nothing more than we already know.

Last edited by John Healy; 11/23/15 3:12 pm. Reason: noted writing at same time as Allen

Re: Tuning Your AMAL Carburetor [Re: Morgan aka Admin] #626961
11/23/15 3:23 pm
11/23/15 3:23 pm
Joined: May 2013
Posts: 5,004
Rotherham - S. Yorkshire
Allan Gill Offline

BritBike Forum member
Allan Gill  Offline

BritBike Forum member

Joined: May 2013
Posts: 5,004
Rotherham - S. Yorkshire
Well written John, it's about time this thread got back on track, may I even request a deletion of some of these posts so we can preserve the good information that was previously posted.


beerchug
Re: Tuning Your AMAL Carburetor [Re: ] #626985
11/23/15 6:30 pm
11/23/15 6:30 pm
Joined: Sep 2013
Posts: 1,733
Pacific northwest
Q
quinten Online confused
BritBike Forum member
quinten  Online Confused
BritBike Forum member
Q

Joined: Sep 2013
Posts: 1,733
Pacific northwest
Originally Posted By needing
Hi guys.
I hear "'same-same' is how we like it" so I will leave it at that for this thread.
Ta.
Owen.


Congratulations , you found a black cat , in a dark room , that is not there

.
.

Last edited by quinten; 11/23/15 6:31 pm.
Re: Tuning Your AMAL Carburetor [Re: John Healy] #626996
11/23/15 7:13 pm
11/23/15 7:13 pm
Joined: Aug 2001
Posts: 2,309
Oztralia
R
Rohan Offline
BritBike Forum member
Rohan  Offline
BritBike Forum member
R

Joined: Aug 2001
Posts: 2,309
Oztralia
Originally Posted By John Healy
Listen guys... this guy is talking trash. His last post convinces me he has no understanding of these carburetors.


There were some bizarre posts on Access Norton BEFORE he even got onto Amals, some folks had figured that out already.

If only he'd had a good supervisor....

Re: Tuning Your AMAL Carburetor [Re: Morgan aka Admin] #627004
11/23/15 8:36 pm
11/23/15 8:36 pm
Joined: Aug 2001
Posts: 2,309
Oztralia
R
Rohan Offline
BritBike Forum member
Rohan  Offline
BritBike Forum member
R

Joined: Aug 2001
Posts: 2,309
Oztralia
Obnoxious as ever....

A downpayment.



I think think think this is the only parts list these occur in ?

Re: Tuning Your AMAL Carburetor [Re: Morgan aka Admin] #627006
11/23/15 8:42 pm
11/23/15 8:42 pm
Joined: Aug 2001
Posts: 2,309
Oztralia
R
Rohan Offline
BritBike Forum member
Rohan  Offline
BritBike Forum member
R

Joined: Aug 2001
Posts: 2,309
Oztralia
Nortons put out an advisory on this, and the 'new' carbs on the 850 ?

Re: Tuning Your AMAL Carburetor [Re: Morgan aka Admin] #627204
11/25/15 4:13 am
11/25/15 4:13 am
Joined: Nov 2009
Posts: 2,220
Netherlands
Peter R Online content

BritBike Forum member
Peter R  Online Content

BritBike Forum member

Joined: Nov 2009
Posts: 2,220
Netherlands
May I suggest the deletion of a number of recently added posts in this thread.
I hate to see this otherwise excellent and well written thread morph into irrelevant squabble which is of no use for any of us.


Peter.
1974 Commando 850
1972 Trident T150T
1961 Goldie DBD34
1969 Benelli 250 sport special
Re: Tuning Your AMAL Carburetor [Re: ] #631985
12/27/15 1:08 pm
12/27/15 1:08 pm
Joined: Aug 2015
Posts: 1,268
Bolton Lancs UK
A
Andy Higham Offline
BritBike Forum member
Andy Higham  Offline
BritBike Forum member
A

Joined: Aug 2015
Posts: 1,268
Bolton Lancs UK
I fail to see how eliminating the throttle stops will improve a carburettor, the only way of adjusting the idle speed now is by cable adjustment. (one of the main weaknesses of the GP carb)
If I was embarking on a programme of improvements to the Mk1, the first would be to sleeve the slide bore with a more suitable metal and fit a chromed brass slide
Next I would machine off the flange fitting and use a modern style rubber mount to isolate the carb from heat and vibration
Further work would be to fit a replaceable pilot jet instead of the pressed in bush and helicoiling the top cap and float bowl fixings BEFORE the threads wear out.
Even then you will still have gloves that are permanently smelling of petrol from the tickler


BSA B31 500cc "Stargazer"
Greeves 200cc "Blue Meanie"
Greeves 350
Greeves 360 Challenger
Suzuki GSX1100 EFE "Sorcerers Apprentice"
GM500cc sprint/LSR bike "Deofol"
Jawa 500cc "Llareggub"
2003 Aprilia RSV Mille "Lo Stregone"
'35 OK Supreme
'36 OK Supreme
Re: Tuning Your AMAL Carburetor [Re: Morgan aka Admin] #631998
12/27/15 2:13 pm
12/27/15 2:13 pm
Joined: Aug 2001
Posts: 1,893
Elko, Nevada USA
dave - NV Offline

BritBike Forum member
dave - NV  Offline

BritBike Forum member

Joined: Aug 2001
Posts: 1,893
Elko, Nevada USA
Andy ... Your ideas for MKI improvements were taken care of in the AMAL MKII Smooth Bore carb, but not the 'conventional' MKII. I have "smoothies" on 3 Gold Stars (GPs in the cabinet!) and haven't looked back. We do keep a conventional 40mm MKII for use on the dirt tracker for AHRMA events.

The only problem I've found is corrected with the easy fix from the fertile mind of GStarRon (RIP).
The "smoothie" doesn't have a idle stop just like a GP carb.
Ron's easy fix is to tap one of the breather holes in the top of the Brass slide for a very short #6 screw. You then adjust this screw, that will touch against the Alu boss beneath the slide, for a nice 800 rpm idle. BTW, hands off the throttle starts are a 'piece of cake' with this idle stop.

I'm told that the nice chrome plated brass throttle slide will back fit into the conventional MKII that has the OEM POS pot metal (Ye Gads) slide that can/will hang up giving you a very fast idle (gulp) when least expected. aargh.


Dave - NV
Page 8 of 8 1 2 3 4 5 6 7 8

Moderated by  Alan_nc 


Home | Sponsors | Newsletter | Regalia | Calendar | Bike Project | BritBike Museum | Spiders Cartoons | "OLD" BritBike Forum | DVD- Manuals & Parts books | BritBike Stickers & Decals
Upgrade to: Premium Membership | Premium Life Membership | Vendor Membership | Site Sponsor Membership
Powered by UBB.threads™ PHP Forum Software 7.6.2