1981 parallel port T140...E-start

seattle##gs · Apr 12, 2025

I am trying to fit MK1 carbs to this head. It would make things easier if I could fit an earlier screw in stub with a flange and bolt the carb on. Is it possible to remove the current stub? It looks like it had a special tool to install it.
Doing it the hard way, I could cut a slot on either side, insert a flat "tommy bar" and give it the heave-ho. It's possible that the head should come off and be heated in the bar-b-que. But first, is it possible to remove the stub at all?

Amal has not made the rubber flange adaptors in a long time and probably never will again. Any ideas?

marshg246 · Apr 12, 2025

seattle##gs said:
I am trying to fit MK1 carbs to this head. It would make things easier if I could fit an earlier screw in stub with a flange and bolt the carb on. Is it possible to remove the current stub? It looks like it had a special tool to install it.
Doing it the hard way, I could cut a slot on either side, insert a flat "tommy bar" and give it the heave-ho. It's possible that the head should come off and be heated in the bar-b-que. But first, is it possible to remove the stub at all?

Amal has not made the rubber flange adaptors in a long time and probably never will again. Any ideas?

I'm pretty sure those are molded in, not screwed in. Why not just use a different head?

Fast Eddie · Apr 13, 2025

They are screwed in, but I’ve no idea what thread type or size was used.

Fast Eddie · Apr 13, 2025

Scroll down to the ‘plate manifolds’ section in the link below.

I don’t have access to measure my T140 currently, but I’m guessing that PM02’s is what you want…

Carburettor Mounting Rubber Manifold Dimension Information Page - Allens Performance Ltd.

Manifolds - Carb Rubbers NITRILE SLEEVE RUBBERS (All dimensions in MM) Part #ABCDEFAppComments Part # A B C D E F App Comments SR01 35.00 35.00 10 (R) 8 (R) 29.00 47.50 VM26/28 SR02 40.00 40.00 8 (R) 8 (R) 31.00 55.00 VM30 Straight SR03 40.00 40.00 8 (R) 8 (R) 31.00 49.00 VM30 (T120)… Read More »

www.allensperformance.co.uk

Fast Eddie · Apr 13, 2025

Of course, I should also say that I really do not believe you need to do this. I know many folk hate the mk2 carbs but as I discovered, the hate is misplaced and they work super well on T140s when set up accordingly.

IMO the hate is due to the complexities caused by none EPA vs EPA spec and issues caused by accidentally having some miss matched parts. Especially that pesky air jet bush… another common fault is perished cold start plunger rubbers.

marshg246 · Apr 13, 2025

seattle##gs said:
I am trying to fit MK1 carbs to this head. It would make things easier if I could fit an earlier screw in stub with a flange and bolt the carb on. Is it possible to remove the current stub? It looks like it had a special tool to install it.
Doing it the hard way, I could cut a slot on either side, insert a flat "tommy bar" and give it the heave-ho. It's possible that the head should come off and be heated in the bar-b-que. But first, is it possible to remove the stub at all?

Amal has not made the rubber flange adaptors in a long time and probably never will again. Any ideas?

Post a picture. Triumph lists no separate inlet stubs but they show the 2 into 1 a d flange mounted so I'm confused. I seem to rememebr differences in the late 70s and early 80s and that the "E" was different. But then I focus on right-shift bikes.

Personally, I would keep the MKIIs.

seattle##gs · Apr 13, 2025

The bike came with no carbs and I'm certain he does not want to replace the head.
I fought with a pair of MK2 carbs on a 1979 Triumph for months. I tried all the suggestions. Even new choke plungers. Always way to rich and a very high idle. I finally tracked it down to a massive leak through the choke circuit after plugging any passage to the chokes. I had a similar problm with a Bultaco and a MK2 carb. The cure was to ditch the carbs and use a concentric. Problem immediately solved. I will never deal with MK2 carbs again.

Fast Eddie · Apr 14, 2025

seattle##gs said:
The bike came with no carbs and I'm certain he does not want to replace the head.
I fought with a pair of MK2 carbs on a 1979 Triumph for months. I tried all the suggestions. Even new choke plungers. Always way to rich and a very high idle. I finally tracked it down to a massive leak through the choke circuit after plugging any passage to the chokes. I had a similar problm with a Bultaco and a MK2 carb. The cure was to ditch the carbs and use a concentric. Problem immediately solved. I will never deal with MK2 carbs again.

Why should he replace the head ? The ‘E’ head is good. It creates swirl. And with bit of measuring and use of a thinner head gasket you get a functioning squish band area.

The idea behind the manifolds I linked is for them to bolt to the concentrics and then slip on to the stock inlet stubs nicely giving you rubber mounted carbs with less components and less space used.

baz · Apr 14, 2025

Fast Eddie said:
Scroll down to the ‘plate manifolds’ section in the link below.

I don’t have access to measure my T140 currently, but I’m guessing that PM02’s is what you want…

Carburettor Mounting Rubber Manifold Dimension Information Page - Allens Performance Ltd.

Manifolds - Carb Rubbers NITRILE SLEEVE RUBBERS (All dimensions in MM) Part #ABCDEFAppComments Part # A B C D E F App Comments SR01 35.00 35.00 10 (R) 8 (R) 29.00 47.50 VM26/28 SR02 40.00 40.00 8 (R) 8 (R) 31.00 55.00 VM30 Straight SR03 40.00 40.00 8 (R) 8 (R) 31.00 49.00 VM30 (T120)… Read More »

www.allensperformance.co.uk

This is really helpful list
I hadn't seen this before

seattle##gs · Apr 14, 2025

Fast Eddie said:
Scroll down to the ‘plate manifolds’ section in the link below.

I don’t have access to measure my T140 currently, but I’m guessing that PM02’s is what you want…

Carburettor Mounting Rubber Manifold Dimension Information Page - Allens Performance Ltd.

Manifolds - Carb Rubbers NITRILE SLEEVE RUBBERS (All dimensions in MM) Part #ABCDEFAppComments Part # A B C D E F App Comments SR01 35.00 35.00 10 (R) 8 (R) 29.00 47.50 VM26/28 SR02 40.00 40.00 8 (R) 8 (R) 31.00 55.00 VM30 Straight SR03 40.00 40.00 8 (R) 8 (R) 31.00 49.00 VM30 (T120)… Read More »

www.allensperformance.co.uk

This is an excellent source. Thanks

Matchless · Apr 15, 2025

seattle##gs said:
This is an excellent source. Thanks

Just don't expect fast delivery if my experience is anything to go by. I ordered a set of connector sleeves, & after almost three weeks gave up & contacted Paypal for a refund. I tried to contact Allens by phone & email, but received no reply.

seattle##gs · Saturday at 11:48 AM

Well, the Triumph fired up with the first kick, thank you new premiers. I couldn't get a sniffle or a pop out of the MK2 carbs. Burlen owes the world an apology for those mk2 carbs.

1981 parallel port T140...E-start

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