Back to my old Amal carbs

ashman

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6 months ago I decided to go back to my old Amal carbies, been running Jim's PWK carbies for the last well can't remember for how long as long as I been running the Joe Hunt Maggie anyway, over 12 years maybe, Jim had set up the PWKs for my motor (cam, ports and open exhaust pipes), the PWKs were good but one big problem they had was sticking floats not all the time but enough to give me a royal pain in the arse, Jim was very helpful trying to fix this problem but it was the left carb I had most problems with and now I have given up trying to fix so out came the old Amals from sitting under my work bench.

Well a major pull down of the Amals and both carbs soaking in a big container of vinegar let them soak for a few days, these Amals were replacements from my original Amal which were flogged out back in the late 70s with about 30k miles on them, the replacement Amals were on the bike for ever after without any problems at all except for replacing needles and jets every 3 or 4 years of running, when they were on my Norton it was a everyday rider work and weekends till right up to 2013 when I brought my new Triumph Thruxton 900 but the Amals where replaced about 2 years before that with the PWKs from bad running so thought it was a good time to replace the Amals.

After all the time sitting under my work bench and pulling them all apart soaking in the vinegar for 4 days they came up like new, I know the needles and jets were replaced before I pulled them out of service because of bad running at the time,but the vinegar did its job of cleaning the inside of the carbs and clean any gunk that had built up over the year, blowing them all out with compress air making sure all gallies were free and clear so put back together, the Norton fired up first kick but was running on one cylinder so another pull down and soaking in the vinegar for 2 days then putting them back on the Norton,but after doing that life got in the way and all work on the bikes stopped with house Reno's that needed to he done and house paint job, cars and a wife breaking with a few health issues just got in the way even the 1200 Thruxton was not ridden much at the time till a week ago.

So 6 months ago when I started to put the Amals back together the left carby the pilot passage was blocked so the small gautar string was used to clear the passage and another few hours in the vinegar I had the pilot screws out and a finger over the holes and when I hit it with the air pressure something blew out the pilot passage and hit my finger so hard was like a sharp needle hitting my finger it hurt, so after that carb cleaner down all passages and everything was clear and spray coming out where it should so carbs went back together and put back on the Norton and before getting fresh fuel everything came to a halt till this week.

Fresh fuel in the tank and first kick she fired up but wouldn't run for long and when I tried to open the throttle it kept dying at the time I put the carbs back on the bike I normally have the oil line to the head in-between the manifolds but was outside the right carb so had to pull the right carb off to reposition the oil line and when off the carb was full off fuel so I pulled the bowl off with easy to check the float height and all looked good so I decided to pull the left carb off and do the same with its bowl, the bowl was only 1/2 filled and to my surprise the float needle was off it mount/position, then back together it must have moved when putting the bowl back on 6 months ago, easy fix, all cable were set and slides adjusted 6 month ago it fired up first kick again and running on both cylinders but rough as gut till adjusting the air screws, running just right now and firing up on every kick so close just got to take it out for a run with my small screw drive and do a final tune when it warmed up, but shopping day yesterday so didn't get a chance to go out on it, still firing up first kick so this afternoon or in the morning will take it out for a good run and tune as I go.

After all the years and mileage on my old Amals the slides are still good with no sign of wear on then, bit of a freak me thinks compared to the original Amals they wore out with only 20k miles on them and they were flogged out, so whether the replacement Amals were not made out of pot metal who know as I brought them new back in 1980 before the conversion to the Featherbed frame and before the internet.

Will let you know how the ride goes and final run tune.

Ashley
 
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I like my old Amals. The slides were sleeved with stainless (30?) years ago and they have been mostly fine ever since. Don't drop them. They come up cleanly from idle and run great for as fast as the Sheriff around here is willing to overlook. If you are far from home on a long dusty road, Do Not use RTV to seal up a split air filter hose...
 
Ash,
You State you have 160ooo miles clocked, repeatably to us all...throu the years here on this forum.

That's alot. I'm thinking out loud now.... and trying to compute throu my grey matter.
No sleeves in the two pairs of Amals that you own? +10 years on the PWK's from JS



When you lift up the slides on yer old Amals to about 1/4 throttle.... how much play do you have??? Do they sound like Maracas front and back? Or do you replace them when pieces of your slide break off and rattled around the cylinder before being spit out of the exhaust valve. Kinda Hard on the piston and head.???
Just wondering?
think of this as "Between two old Thick skinned Mates at a pub so no one else gets their Hair on fire"
I've been known to do that to some here.
Kind regards.
 
As I say I think I have a freak Norton, since I owned it since new and most of its life was a everyday rider, yes it's had its time off the road from the conversion build to the Featherbed and when I had fractures in the crank cases and chasing up replacements but I always average between 6k to 10k miles a year and it was semi retired in 2013 when I brought a new Thruxton but still riding the Norton monthly.
As for these Amals they bought them new in 1979 but both new carbs were left hand carbs and bit of a hassle sending one back and getting a right hand carb sent and this was before the internet so got the right carb just before the conversion to the Featherbed in 1980 and took 2 1/2 years before getting back on the road so from late 1982 to 2011 these old Amals have been on the Norton and have 120k + miles on them.
As for the slides they are looking good with only very slide movement in all opening positions of the bores, there is no gouged out marks or wear on the slide, no cracks or broken bits, if I have to lift the needles up when after I take it for a ride as part of the final tune as they are set on the middle clip I will take a pic of them but I just don't think about taking pics when I do a jobs I just get into it, but as I say life gets in the way of bike times sometimes.
We also have been getting very hot summer days here and having a steel shed/workshop it gets a bit hot inside, I do have a cover awning off the shed that is open on the sides and front where I can wheel the lift table out of the she with the bike on it to work in a cooler area we get a good afternoon sea breeze coming off Moreton Bay.
I do know a lot about wear and tear of Amal carbs and vibrations and solid manifolds do wear out needles and jets over time why I replace them every 3 years when it was a everyday rider, I keep up the maintenance on my Norton and thank it with a pat on the tank after every ride, maybe why I have a freak of a Norton and why it's been so good to me even with a hard life in my youth, I was 17 years old when I brought my Norton new and a canned the sh.t out of it for the first 4 + years of it life, yes young and silly.
 
My original Amal carbs had so much wear in the slides if it didn't have the slide pin would be able to spin the old slides around lol and they had deep gouges in the slides from wear, you could hear them rattling, even when worn they still ran but the Norton wouldn't idle and had to keep on the throttle when stopped at lights and all.
One thing as well the original slides and carbs were a dark grey pot metal but the replacement Amals the slides and bodies are a light grey metal, I am not sure who the supplier was as I ordered these Amals through the Norton owners club that my mate was a member in the late 70s but they would have come from Amal I am sure.
By the way these replacement Amals cost me $100 for both Amals back in 1979 but in my time that was near 2 weeks pay.
 
Why replace them if they not showing wear from the time they been on my Norton and they are idling fine even with a quick tune from firing it up, I am not a rich man and been retired for 9 years, most of my upgrades where done when working and at the time I was getting all my upgrades about 12 years ago when the Aussie $$$ was even with the US $$$ at the time, normally the Aussie $$$ is around 70c to the US $$$ or even lower.
Why replace when not broken I worked as a T/A to maintenance fitters and if you want things to last you got to keep up all maintenance.
As I have said the slide aren't showing wear, isn't that why everyone replace their old Amals as I did back all them years ago and maybe and it's a big maybe my old replacement Amals might not be made of pot metal like the original Amals because these Amals not showing any wear in them and even my old mate said they look and feel great before putting them back together and he is a old Triumph man with Amals.
 
I rather ride than to find out why I have been lucky, but as I say they aren't pot metal as the same as the the original Amals who knows they just complete different in colour in metal, maybe Amal changed the metals earlier on from pot metal I have no idea as my orginial Amals were completely flogged out at 20k miles and the replacements have lasted so long to be still good.
I have no answers to why, just a freak, lucky or just good maintenance or maybe patting my tank and thanking my Norton for a great day out has helped, or I did something right when I built the 850 Commando/Featherbed over 40 years ago.
Even my old mate Don who got me into Norton's and Featherbed frames when I was 17, we are still mates and even Don can't believe how lucky I have been with my Norton and its reliability and the mileage it has done and it keeps going, and coming up to 47 years of ownership in June.
 
If they ain't broke don't fix them.
Mine were leaking air and rattled like a marble in a can.
After having them sleeved and a complete overhaul it was like having a brand new set of carbs.
I just wanted to stay with the originals and an overhaul gave me a reason to hang in the shop and drink beer and listen to baseball on the radio instead of listening to you know who.

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If they ain't broke don't fix them.
Mine were leaking air and rattled like a marble in a can.
After having them sleeved and a complete overhaul it was like having a brand new set of carbs.
I just wanted to stay with the originals and an overhaul gave me a reason to hang in the shop and drink beer and listen to baseball on the radio instead of listening to you know who.

View attachment 105035View attachment 105032View attachment 105034
Looking good
How many miles did you get out of yours before they wore out?
 
I have a set with 36,000 miles on. They do have a fair bit of play, but the bike still runs nicely.
Are the bikes that wear them out so quickly fitted with air filters?
I see some UK bikes just running open bellmouths.

Glen
 
I am convinced that extra time and care inspecting and assembling carbs or any other component on these machines pays back in spades in reliability and longevity
Yes I agree
The new amals I bought had not been fettled at all
There was swarf in the float bow and the slides were razor sharp from machining
I had to go all over them with a milk stone
They wouldn't have lasted 5 minutes
 
I have a set with 36,000 miles on. They do have a fair bit of play, but the bike still runs nicely.
Are the bikes that wear them out so quickly fitted with air filters?
I see some UK bikes just running open bellmouths.

Glen
I ran mine with a double k&n
I still have the carbs and filter I may consider getting them re sleeved one day and machined for premier pilot jets if I ever go back to them
 
You must have a freak Norton Ash
I'd say about 8000 miles before the slides are worn out in my experience

I got 10 x that (85K miles) out of my Amals before sending them out for Sleeving, and the Atlas was still idling well. They were originals on my 1962 build Atlas bought new in 1963, and so titled.

And I ran open bellmouths nearly all those miles.

Slick

Oh, one oddity about my Amals...... neither has a Model/ Configuration number stamped on the mounting flange ...... were they specially selected by Norton?
 
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I got 10 x that (85K miles) out of my Amals before sending them out for Sleeving, and the Atlas was still idling well. They were originals on my 1962 build Atlas bought new in 1963, and so titled.

And I ran open bellmouths nearly all those miles.

Slick

Oh, one oddity about my Amals...... neither has a Model/ Configuration number stamped on the mounting flange ...... were they specially selected by Norton?
I think monoblocs like you have lasted a bit longer
 
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