Author Topic: Mk5 carb replacement (Read 1102 times)

dalgrae · « **on:** 05 Jul 2023 at 16:24 »

Hi the right hand carb on my Mk5 is running rich,with the slide bore quite badly worn,I have tried various things,but no change,does anyone have any experience with the Australian remake of the 274 body,as I know of one that is available.

Regards. Colin

EW-Ron · « **Reply #1 on:** 05 Jul 2023 at 23:03 »

Quote from: dalgrae on 05 Jul 2023 at 16:24

does anyone have any experience with the Australian remake of the 274 body

Dimensionally they were identical copies.
But cast in brass - from scrap WW2 shell casings !
(the makers were sued by Amal for patent infringement )
(and copped a minor penalty - Amal not knowing the scale of the manufacture)

They are like all carbs - if in good condition, they work as advertised.
If they are worn, maybe not so good.

Have you looked at the jets/needle etc in your carb. ?
If they are like new, the richness likely would be much reduced ?
If you can hear the slide click clacking away, maybe it is time for action ...
As always, float height is critical.

EW-Ron · « **Reply #2 on:** 06 Jul 2023 at 00:28 »

Its perhaps worth adding that Burlen these days are remaking a whole range of Amal carbs,
so may be making something suitable that would be BRAND NEW ?

It cannot be overstated how marvellous it is to not have to fight with worn out carbs.
Although a tad pricey when it comes to 2 or more of them ...

There also used to be folks who could sleeve worn out carbs, and bring them back to like new.
With less of the wallet lightening experience.
This also keeps bikes more original - if the carbs are still original.

dalgrae · « **Reply #3 on:** 06 Jul 2023 at 07:18 »

Hi thanks for these replies,the carb that is available to me is aluminium not brass,Burlen have said to me no plans to remake the 274

Colin

EW-Ron · « **Reply #4 on:** 06 Jul 2023 at 08:56 »

Quote from: dalgrae on 06 Jul 2023 at 07:18

aluminium not brass

That adds an interesting twist to the tale....

graeme · « **Reply #5 on:** 07 Jul 2023 at 05:42 »

If the bodies/slides are flogged out, they can always be resleeved

dalgrae · « **Reply #6 on:** 07 Jul 2023 at 15:44 »

Hi I have tried to attach a couple of photos of the new carb body I have now obtained

Image converted from attachment to linked file to correct aspect ratio. Please see Taking photos with mobile/cell phones. - Dave, 08July2023

dalgrae · « **Reply #7 on:** 07 Jul 2023 at 15:46 »

Hi sorry second photo as attached

Image converted from attachment to linked file to correct aspect ratio. Please see Taking photos with mobile/cell phones. - Dave, 08July2023

cardan · « **Reply #8 on:** 08 Jul 2023 at 00:42 »

Pretty sure you'll find it's bronze, cadmium (?) plated. As the attached advert says, Allparts made and sold parts Australia-wide, often using the trademark "Diecut" even for parts that weren't diecut.

Leon

EW-Ron · « **Reply #9 on:** 08 Jul 2023 at 02:18 »

The weight would be a dead giveaway ...

A chap turned up at a swap meet here (car boot sale) with about a ton of those brass bodies.
He had been tasked with taking them to the scrap man, but came by the sale first.
He said it worked out about $5 per body. (in various stages of completeness)
Talk about a free-for-all ! (not literally).
Many were unidentifiable though, since they weren't stamped with any numbers.
Std Amal parts all fit .
I was doing an Enfield at the time, so went for some long necks (to clear the magdyno)

dalgrae · « **Reply #10 on:** 08 Jul 2023 at 07:36 »

Hi thanks for this ,so were they any good

Colin

dalgrae · « **Reply #11 on:** 08 Jul 2023 at 07:49 »

Just weighed the bare body of one carb and it is 85 grams.

Colin

Jonathan Hewitt · « **Reply #12 on:** 08 Jul 2023 at 08:33 »

Morning Colin, out of interest I have weighed an LDMCC copy in aluminium and that comes in at 85 grms also.
Have a nice day
Jonathan

dalgrae · « **Reply #13 on:** 08 Jul 2023 at 08:37 »

Mine also were obtained via LDMC spares

Colin

EW-Ron · « **Reply #14 on:** 08 Jul 2023 at 08:43 »

Perhaps they can advise more on the source of these ?

Bronze ones are HEAVY !
Unworn and complete and to the right spec, they are as good as any Amal.
All the bits are fully interchangeable.

dalgrae · « **Reply #15 on:** 08 Jul 2023 at 08:53 »

Hi thanks for this ,mine are unused ,I have ordered a new slide and when available will fit to my bike

Colin

eddie · « **Reply #16 on:** 13 Jul 2023 at 15:55 »

From the photos of the repro bodies, they look like the ones that were cast in Australia some 20 years or so ago (and we were supplying through LDMCC spares). They were definately cast in Aluminium (as were the originals).

Colin, if you have access to a lathe, it is quite easy to bore the original carb body out until it cleans up. Then skim down the slide until that cleans up, then turn up a brass sleeve, solder it to the slide and carefully cut the 2 slots down the sides.

Regards,
Eddie.

dalgrae · « **Reply #17 on:** 14 Jul 2023 at 08:33 »

Hi thanks for this

Colin

dalgrae · « **Reply #18 on:** 17 Jul 2023 at 16:58 »

Hi again,so I have now fitted the new carb body along with a new slide,and the rest of the existing parts,my question now is ,how to synchronise the carb slides when I open the throttle,the only way I can come up with is to have a second person looking at one carb whilst I operate the twist grip and look at the other carb slide.Please advise if there is another method

Regards. Colin

Red · « **Reply #19 on:** 17 Jul 2023 at 21:13 »

It might be a crude way of doing it but I use a cocktail stick under each throttle slide and then open the twist grip slightly and check and adjust each throttle cable so both cocktail sticks can be just pulled out with the same amount of resistance. Has always worked for me. Obviously without the engine running. You may then need to finally adjust each throttle cable by the same amount along with the throttle idle screws and air screws to achieve an even tick over

Roy

dalgrae · « **Reply #20 on:** 18 Jul 2023 at 07:06 »

Hi thanks for this