New Amals Replace Mikuni - What a difference!

Jed · Jun 14, 2014

phillyskip said:
I'm happy that you're getting good results with your new carbs .I am in the Mikuni camp,in fact, every one of my old British bikes has them. The problem some have with a Mikuni set up is that they buy the conversion kits which are supposed to be "jetted correctly" ,but in reality they never are. Each bike is different. The advantage of the Mikuni is it's ability to precisely dial in each circuit on the carb to give you exactly what you need. Most don't want to bother to do that,or don't know how. The end result is a bike that is out of tune,or "good enough" I spend a ton of time dialing in my Mikuni set ups,but once you get them right you never have to touch them again. Just my 2 cents.......Skip

Yep horses for courses
The SU (HIF6) on my MK3 had a complete refurb while I built the bike. I was a bit thrown with the idea but since it appeared to have been on the bike since new (or not long after) I decided to give a go
Norton were trialling the SU around the end of production and apparently were considering it as standard had production of the commando continued beyond the MK3
On a recent run over 2500 km alongside a MK2A using the same fuel (95 octane with flash lube additive) low down was just as quick, over 60 MPH the MK 2 with Amals (very well tuned) was more responsive but both bike cruised two up at 70 MPH with no problem
So a bit more top end but over 30 litres more fuel over the same distance (in the MK2) The throttle with the SU is light and responsive and cold starts are no problem (I do live in a warm climate though)
So I guess a properly set up carby regardless of make is a good thing as long as the ride is trouble free and the rider is happy

Jed
The only drawback with the SU is oiling the dashpot but there is a work around for that but it's not annoying enough yet to worry about

phil yates · Jun 14, 2014

Jed said:
phillyskip said:

I'm happy that you're getting good results with your new carbs .I am in the Mikuni camp,in fact, every one of my old British bikes has them. The problem some have with a Mikuni set up is that they buy the conversion kits which are supposed to be "jetted correctly" ,but in reality they never are. Each bike is different. The advantage of the Mikuni is it's ability to precisely dial in each circuit on the carb to give you exactly what you need. Most don't want to bother to do that,or don't know how. The end result is a bike that is out of tune,or "good enough" I spend a ton of time dialing in my Mikuni set ups,but once you get them right you never have to touch them again. Just my 2 cents.......Skip

Click to expand...

Yep horses for courses
The SU (HIF6) on my MK3 had a complete refurb while I built the bike. I was a bit thrown with the idea but since it appeared to have been on the bike since new (or not long after) I decided to give a go
Norton were trialling the SU around the end of production and apparently were considering it as standard had production of the commando continued beyond the MK3
On a recent run over 2500 km alongside a MK2A using the same fuel (95 octane with flash lube additive) low down was just as quick, over 60 MPH the MK 2 with Amals (very well tuned) was more responsive but both bike cruised two up at 70 MPH with no problem
So a bit more top end but over 30 litres more fuel over the same distance (in the MK2) The throttle with the SU is light and responsive and cold starts are no problem (I do live in a warm climate though)
So I guess a properly set up carby regardless of make is a good thing as long as the ride is trouble free and the rider is happy

Jed
The only drawback with the SU is oiling the dashpot but there is a work around for that but it's not annoying enough yet to worry about

Jed
For whatever reason, my experience with the SU was opposite to yours. Throttle was very heavy and 10 kick start when cold was the norm. That was back in about 1982. So maybe things have changed a lot with the SU. I was very disappointed with it. Performed okay but cold starting was a nightmare. I live in a relatively warm climate too. Or did then.

Phil

mschmitz57 · Jun 14, 2014

I got my `73 850 Commando last year and it came with a single 34mm Mikuni conversion. It was supposedly installed and sorted-out by a competent Brit bike mechanic in Chicago. I thought the bike had subtle flat spots, and flaccid acceleration. Nowhere near as quick as my `71 750. Yeah, it idled OK. I checked the jetting and Sudco verified it was correct. I suspect the flat air filter didn't help matters.

I decided to install dual carbs on it over the winter, mainly because I hated the way the Mikuni looked with it's huge 2into1 manifold and flat pancake air filter, and fuel line running all over the place. This is just my personal opinion. I know a lot of people here love their Mikuni conversions (God love you). In a moment of internet abandon I clicked the "Buy Now" button on a set of JSM flat slides. The difference in acceleration was amazing. The bike pulls really hard throughout the range and really takes off over 4500 rpm. Now I've never ridden an 850 with original dual 932 Amals, perhaps they all run like this. I rode a Mk3 with a Mikuni conversion a few times and it too had flaccid acceleration. My `71 750 with dual 930 Amal's which I sleeved and rebuilt had pretty good acceleration but my 850 with dual carbs seems way faster now. Maybe because I'm 10 years older, who knows. This isn't a Amal vs PWK debate. I'm only writing this to convey my observations of single Mikuni vs dual carbs converted back to back on the same bike. Just my $.02.

My 750 Atlas Cafe Racer has a single 32mm Amal carb and it runs fine, starts and idles great, but the acceleration has never thrilled me.
Now I like to treat the old girl with respect so I cut her some slack, still I can't help but wonder what a set of dual carbs would do for it's performance.
I have a set of 930's on the shelf, all rebuilt and ready to go, but I can't bring myself to risk giving-up the easy starting and idling.

ps
I'm using larger oval pod filters from on the PWK's which may help engine breathing even more.

I had thought about a new set of Amal Premiers for the 850 because I like keeping the bike trad (although now that I think about it the Amals are a pain to remove along with the stock air filter, I can pop the PWK + filter off in about a minute with a screwdriver and without removing the tank).

phil yates · Jun 14, 2014

mschmitz57 said:
I got my `73 850 Commando last year and it came with a single 34mm Mikuni conversion. It was supposedly installed and sorted-out by a competent Brit bike mechanic in Chicago. I thought the bike had subtle flat spots, and flaccid acceleration. Nowhere near as quick as my `71 750. Yeah, it idled OK. I checked the jetting and Sudco verified it was correct. I suspect the flat air filter didn't help matters.

I decided to install dual carbs on it over the winter, mainly because I hated the way the Mikuni looked with it's huge 2into1 manifold and flat pancake air filter, and fuel line running all over the place. This is just my personal opinion. I know a lot of people here love their Mikuni conversions (God love you). In a moment of internet abandon I clicked the "Buy Now" button on a set of JSM flat slides. The difference in acceleration was amazing. The bike pulls really hard throughout the range and really takes off over 4500 rpm. Now I've never ridden an 850 with original dual 932 Amals, perhaps they all run like this. I rode a Mk3 with a Mikuni conversion a few times and it too had flaccid acceleration. My `71 750 with dual 930 Amal's which I sleeved and rebuilt had pretty good acceleration but my 850 with dual carbs seems way faster now. Maybe because I'm 10 years older, who knows. This isn't a Amal vs PWK debate. I'm only writing this to convey my observations of single Mikuni vs dual carbs converted back to back on the same bike. Just my $.02.

My 750 Atlas Cafe Racer has a single 32mm Amal carb and it runs fine, starts and idles great, but the acceleration has never thrilled me.
Now I like to treat the old girl with respect so I cut her some slack, still I can't help but wonder what a set of dual carbs would do for it's performance.
I have a set of 930's on the shelf, all rebuilt and ready to go, but I can't bring myself to risk giving-up the easy starting and idling.

ps
I'm using larger oval pod filters from on the PWK's which may help engine breathing even more.

I had thought about a new set of Amal Premiers for the 850 because I like keeping the bike trad (although now that I think about it the Amals are a pain to remove along with the stock air filter, I can pop the PWK + filter off in about a minute with a screwdriver and without removing the tank).

Interesting,
I guess we've all had different experiences. I've tried single Amal, twin Amal, single SU and single Mikuni. But all on different bikes. Dual carbs will always give best performance, but mostly at the top end. Nothing wrong with twin Amals, but fiddly in my opinion. Horses for courses. Or as 72combat would say, I ain't shearing this sheep with anybody!!

Phil

midnightlamp · Jun 14, 2014

I'll chime in with my $0.02 as an engineer who dabbles in this stuff :mrgreen:

Mikuni VM's and PWK's are better built carbs than the original AMAL concentrics in nearly every way. More tuning options, better flow, and a lot tighter tolerances (tight slide to carb clearances to keep vacuum up and prevent air leaks). They are just better carbs all in all, can't argue that one much. The only real nice features the amals have is that they have less jets to get horribly wrong, and that the tickler works by flooding the float which richens up the mixture but automatically tapers off to normal levels (like an auto-choke). You are however comparing carbs that have a few decades in difference on the tooling used to make them, which definitely doesn't work in the favour of the original amals.

People like the amals because the factory jetting and design usually lets you pop one on a brit bike, and not really have an issues that'll keep the bike from running or let it run really funny. Limited pilot + cut-away selection lets you easily tune the carbs, and because they're pretty free flowing up top you can easily tune the top end for good performance as well. With the new premiers, the manufacturing tech is bumped up a few decades worth, and you don't get most of the issues people run away from (air leaks around the slide, stiction and galling of slides in bodies without a fair clearance, etc...). Gives you a good option that lets you use stock everything and get all the advantages the originals offered with minimized downsides (same ones, but just less so).

The PWK's flats and twin VM's offer all of that, but better, as long as the jetting is right. The flatslides can be a little finicky tuning wise, as the dynamics of running an oval venturi (for the smaller ones) and a flat slide can cause some tuning difficulties. It's also very easy to get them jetting totally wrong (bleed type needle jets vs non-bleed, etc...), which will result is poor performance and is not something that is all that easy to sort out without some in-depth knowledge or a dyno/wideband. If you can't do the baseline tuning yourself (which would take you decades by just plug chopping) you rely on a properly jetting setup from a vendor that you can then tweak. This is where people get good and bad feelings about these carbs, as some vendors who sell them do not have them set up right. Pound for pound, you'll be able to get more performance out of a fresh Mik VM / PWK FS than either the original or premier AMALs, if they're jetted right.

The issues you will see commonly: Incorrect needle jets resulting in weird flat spots and tuning instability in the mid range, poor starting performance with enrichment jets and a fine balance on some bikes between having a functioning choke and having a low number of kicks to start (cold engine vs. cold weather performance), massive issues with actually physically reaching adjustment screws, difficulty with general serviceability with carbs on bike, and the fact that you'll finance away your life and savings if you want to develop the jetting on your own (jets add up quick, and the tuning takes a long time without a wideband at a minimum).

If you go with single carb however, most of this argument breaks down. The main reason people get a single carb is just because they don't want to do all the fiddly work of setting up a pair of carbs. You will generally get lower performance (especially up top), but have a "lower maintenance setup".

Coles notes:
- You shouldn't buy a single carb expecting stellar mid/top range performance. The single kits are often undercarb'd for top end, and are more designed for a "kick and forget" mentality (which is fine).
- If someone has done the legwork to jet a set of PWK's or VM's properly for your bike, they'll probably give the same/better performance than the AMAL equivalents with the potential for more performance and more stability all around. They will likely be a pain in the arse to adjust and you will also likely have to deal with cleaning a little more religiously.
- If you paid money for a set of AMAL premiers, you basically have the same carb performance as a stock bike (which is perfectly fine as well) and should have nearly zero issues getting it running and tuned. You will also generally have good stability in your jetting and carb performance due to the modern design/manufacturing. A sleeved set of originals or unworn set should give similar results, except the pilot circuit.
- If you're running a set of clapped out original 930's or 932's where you can physically jiggle the slide in the bore and think that you've still got the ideal setup, you're dreaming :shock:

Biscuit · Jun 14, 2014

^^^^ Now that's a good post.....To a thread that's been all the way to the moon and back! ^^^^

Jed · Jun 15, 2014

For whatever reason, my experience with the SU was opposite to yours.

Phil[/quote]

Seems a common thread that everyone has a different experience/opinion on any type of carby set up
My SU was put back to as new condition by Midel in Lakemba and so far has been good enough for me Its a (HIF6) series will 44mm outlet
It has plenty of grunt down low but less to offer up top but 70 MPH is fast enough for me these days and I have never taken it all the way especially with the memories of building the bike still pretty fresh and no desire to go there again just yet
If I had to go for another carby I would probably try the Mic as less time fiddling appeals to me and there is a lot more info available on them
Its a shame the comprehensive overview by midnightlamp did not include any commentry on the SU but was very informative non the less

Cheers

JED

phil yates · Jun 15, 2014

Jed said:
For whatever reason, my experience with the SU was opposite to yours.

Phil

Seems a common thread that everyone has a different experience/opinion on any type of carby set up
My SU was put back to as new condition by Midel in Lakemba and so far has been good enough for me Its a (HIF6) series will 44mm outlet
It has plenty of grunt down low but less to offer up top but 70 MPH is fast enough for me these days and I have never taken it all the way especially with the memories of building the bike still pretty fresh and no desire to go there again just yet
If I had to go for another carby I would probably try the Mic as less time fiddling appeals to me and there is a lot more info available on them
Its a shame the comprehensive overview by midnightlamp did not include any commentry on the SU but was very informative non the less

Cheers

JED[/quote]

Yes Jed
midnightlamp's post was most informative and I'm sure appreciated by all. I'm going back a long long time ago when I tried the SU. I bought it from Fair Spares when holidaying in England with my brother in about 1982. The Commando I had at the time was a 1969 (maybe 68) Commando which I bought with a single Amal fitted. The SU ran the bike nicely once started. "Once started" when cold was the key issue. 10 kicks or there abouts was a pain. I lived in Sydney at the time so it wasn't a matter of super cold mornings like here in Mittagong. No tickle capability (and if I recall, no choke) was a pain. Heavy throttle? Maybe there was a better way to rig it but I knew of none. Model number? I don't know, can't remember. I knew no one else who had tried one. It is a beautiful carbi but I found the afore mentioned issues most annoying.

Sounds like you've got it to cover your requirements nicely. I would certainly be happy to run one again if cold starting and heavy throttle are no longer an issue, but the VM Mikuni seems to run the bike so well. Just never needs adjusting and other than top end (which I definitely noticed up around 100mph) seems to accelerate the bike very well. Starts easy, never gives a problem and provides good performance. Obviously a lot of other Norton folk find the same. I imagine two of them would be really good. But I like the simplicity offered by running one carbi regardless of make or type.

Phil

Nortiboy · Jun 15, 2014

[quote="phil yates.

but the VM Mikuni seems to run the bike so well

Phil[/quote]

Japanese air into British motors. Heathens

Jed · Jun 15, 2014

Nortiboy said:
[quote="phil yates.

but the VM Mikuni seems to run the bike so well

Phil

Japanese air into British motors. Heathens[/quote]

The history on Amal Mikuni - the inventors son/partner went to breath Japanese air. If Norton had the same foresight one can only wonder where the Marque would be now
BTW You don't get much more british these days than an SU

Jed

phil yates · Jun 15, 2014

Jed said:
Nortiboy said:

[quote="phil yates.

but the VM Mikuni seems to run the bike so well

Phil

Click to expand...

Japanese air into British motors. Heathens

The history on Amal Mikuni - the inventors son/partner went to breath Japanese air. If Norton had the same foresight one can only wonder where the Marque would be now
BTW You don't get much more british these days than an SU

Jed[/quote]

Yes indeed, I am a total hypocrite I agree. I think I might have Japanese spark plugs too. And Italian wheels. American handlebars, Chinese light globes and fuel from Singapore. Not to mention a soon to be fitted Australian Fullauto head.
I really don't know what I am doing in this pro British forum at all! Luckily everyone else in here is riding Japo, or I'd be skinned!!

Phil

phil yates · Jun 15, 2014

Nater_Potater said:
Well, I've had Bonwit's rejected-dejected 34mm single Mikuni on the old girl now for a week/200 miles, and, after a couple of pilot jets changes (started at 40, dropped to 30, ended-up at 32.5), I'm ecstatic! Sure, I'm basing that off of 10,000+ mile Amals, but I've been around long enough to know a good thing when I see it. That's not to say that I wouldn't like the Premiers even more, but the wallet blah-blah-blah...
This morning on the way into work, some joker in a rice-burner dove off ahead of me into my favorite shunt lane that swoops off the side of the interstate. Not being one to be left out of the fun, I followed it in "just to observe". Picture a quarter-mile stretch that has a fairly gentle right-hand sweeper, followed by a bit tighter left-hand, then dumping back onto the interstate in an opening-up right bank. It doesn't get a lot of traffic, the surface has great traction, and all three turns are nicely supered.
I gave the Sake-sucker some room, and I'm glad I did! As I came roaring up behind him exiting the third turn, I glanced at the speedo in time to see the needle sweeping past 90 mph! This is the first time I've ever had her going that fast. Thanks to all the input I've garnered from this forum, the isos, swingarm clamps, and tires worked wonderfully. She railed over in the turns as if there was plenty left to give. Very confidence inspiring, to say the least.

Based on that little jaunt, there's absolutely no doubt in my mind that she'll go well over the ton with that piece of junk Mikey carb. That, and no more stink-finger, and it'll idle at the traffic lights without needing steady pressure on the twist grip.

By the way, Bonwit, you forgot to include the dress when you sent me the carb. Don't worry about the lipstick, though, as I'm sure my wife can recommend something that would suit my complexion...

phil yates said:

When I bought my first Mikuni carburettor, it came supplied with a dress in the box.
I put that on. I think I looked pretty cute.
And I always wear lippy when I go to the pub!

Click to expand...

Nathan
For some reason my computer opened up on this post of yours which I can't recall. Funniest thing I've read in a long time. Obviously you like the Mikuni too.

Phil

Bernhard · Jun 16, 2014

mschmitz57 said:
I

I decided to install dual carbs on it over the winter, mainly because I hated the way the Mikuni looked with it's huge 2into1 manifold and flat pancake air Just my $.02.

My 750 Atlas Cafe Racer has a single 32mm Amal carb and it runs fine, starts and idles great, but the acceleration has never thrilled me.
Now I like to treat the old girl with respect so I cut her some slack, still I can't help but wonder what a set of dual carbs would do for it's performance.
I have a set of 930's on the shelf, all rebuilt and ready to go, but I can't bring myself to risk giving-up the easy starting and idling. quote]

I too had an Atlas which had a single monoblock carb which I fitted Concentrics.
You will be reasonably safe with 930 carbs, just make sure that the inlet ports in the cylinder head are 30mm or smaller, if necessary make a reducing split sleeve if it is 32 mm dia in head
With the single carb you may find that there is already a split sleeve for the single carb already in there.

midnightlamp · Jun 16, 2014

Thanks for the kind words guys

I'd put the 930's on, as a 932 is not an awful lot of carb for a single carb setup. :shock:

A set of amals without slide leaks and a functional tickler should be nearly the easiest set-up to kick over. It also only takes me ~10 minutes to sync the carbs, which I end up doing every two months and they give me no problems. You just put a pair of drill bits in, cutting tip out so the chuck side is in (3/32" for me), so that the cutaway clamps them, and increase the idle screw until they just droop on both sides. Then you lift the slides and make sure they bot disappear at the same time by feeling the top of the carb throat while lifting the slide (find the point when both slides just seem to disappear, adjust individual cables to do this). Then just drop both slides down equally (1/4 turn at a time) until the idle is where you want, then add some slack in to the throttle. I also find running a twin pull setup and a pair of cables makes life a lot easier in this regard and like the response better. If you do that and adjust the pilot circuits (once a year or so), you should be running very well.

The one thing that surprises me is that not a lot of people consider the other carb options out there, because of a fixation on big single carbs. Amal Mk2's are very nicely built and can be picked up used for cheap. Twin VM30's or VM32's are the same story.

Also, no comments on SU's as I haven't had enough experience with them to give an accurate statement! I'm more of a weber, dellorto, lectron, posa, etc... guy.

Hobot · Jun 16, 2014

Its a big world of fueling options and nothing will satisfy all of us but by golly by far the fastest craft I ever had or ridden in public was a '68 750 with dual 30 mm AMALS. IF not out for top end land speed attempts, just blowing off others within 1/4 mile its very hard to beat 30mm AMALS though nothing wrong with any thing else except its not Norton and may not be able to dial in to match the quaint old gasoline droolers.

Bonwit · Jun 16, 2014

I just got back from a ride, and as the original poster on this topic, I stand by my statements. You couldn't pay me to re-install that Mikuni. I'll also mention that the Mikuni's jetting was gone through and optimized by Bill Blake at Rockypoint. He made it better, but not as good as these Amal Premieres I bought from him.

phil yates · Jun 16, 2014

Bonwit said:
I just got back from a ride, and as the original poster on this topic, I stand by my statements. You couldn't pay me to re-install that Mikuni. I'll also mention that the Mikuni's jetting was gone through and optimized by Bill Blake at Rockypoint. He made it better, but not as good as these Amal Premieres I bought from him.

Bonwit
I noted on your original post your satisfaction with your new Amals. I find the single Mikuni does what you like about your Amals all very nicely up until about 100mph, then definitely performance drops off. But I've never like you have, compared the Amals versus single Mikuni on the same bike. Do you notice improvement in acceleration?

Did you sell your Mikuni set up? I was really after a 36mm and presume yours is/was 34mm. But if not sold I'd be interested. PM me if it's not yet sold.

The new MkIII I've just bought is running twin Amals and idle is a bit erratic. But that can soon be sorted. Also I noticed a somewhat heavier throttle movement, to be expected I guess pulling two slides up at once. Nothing that can't be cured. Acceleration was decidedly poor or slow compared to my current MkIII with single Mikuni. But that's all to do with those choking bean cans (I have pea shooters fitted on mine). You can feel when a motor is restricted and it certainly is. My early Norton books claim the bean cans provided no performance decrement. Bullshit!!

Maybe I was a bit exuberant chucking those Amals in the Wingecarribbee river. Shouldn't have thrown my kick starter in there either, but you live and learn.

Phil

B+Bogus · Jun 16, 2014

I'm looking for an excuse to buy a set of the new Amal Premiers, but the originals on my 850 are still great, and idle at 7-800 rpm with a Trispark ignition.
I came close with my Combat, but it never got bad enough to warrant the expense, and although I've now sold it, the new owner feels the same way.

Regarding fitting the rubbers to the filter housing, I've found that with new rubbers (I.e. still nice and flexible) The only way that works is to get them onto the screwed on flange on the carb, and then persuade them into position in the filter plate - or the MkIIA plastic airbox in my case.
Once in position on the carb they did co-operate - my knuckles only took a couple of days to stop stinging, too

Bonwit · Jun 16, 2014

phil yates said:
Bonwit said:

I just got back from a ride, and as the original poster on this topic, I stand by my statements. You couldn't pay me to re-install that Mikuni. I'll also mention that the Mikuni's jetting was gone through and optimized by Bill Blake at Rockypoint. He made it better, but not as good as these Amal Premieres I bought from him.

Click to expand...

Bonwit
I noted on your original post your satisfaction with your new Amals. I find the single Mikuni does what you like about your Amals all very nicely up until about 100mph, then definitely performance drops off. But I've never like you have, compared the Amals versus single Mikuni on the same bike. Do you notice improvement in acceleration?

Did you sell your Mikuni set up? I was really after a 36mm and presume yours is/was 34mm. But if not sold I'd be interested. PM me if it's not yet sold.

The new MkIII I've just bought is running twin Amals and idle is a bit erratic. But that can soon be sorted. Also I noticed a somewhat heavier throttle movement, to be expected I guess pulling two slides up at once. Nothing that can't be cured. Acceleration was decidedly poor or slow compared to my current MkIII with single Mikuni. But that's all to do with those choking bean cans (I have pea shooters fitted on mine). You can feel when a motor is restricted and it certainly is. My early Norton books claim the bean cans provided no performance decrement. Bullshit!!

Maybe I was a bit exuberant chucking those Amals in the Wingecarribbee river. Shouldn't have thrown my kick starter in there either, but you live and learn.

Phil

Phil, yes, I notice an improvement in acceleration with the Amals. The other surprise is how well the bike idles, A nice slow lope, even after a short warmup. I never had that with the Mikuni. I'm sure it's because they're new, but hopefully the anodized slides will wear better than the old Amals. As for the throttle pull, it's very light. . . almost too light for my taste. It's become obvious to me that you just cannot compare these new Amals with a set of 40 year old originals.

By the way, I did sell the Mikuni kit, and the new owner is thrilled with it (which I'm glad of). To each his own.

Best

phil yates · Jun 16, 2014

Bonwit said:
phil yates said:

Bonwit said:

I just got back from a ride, and as the original poster on this topic, I stand by my statements. You couldn't pay me to re-install that Mikuni. I'll also mention that the Mikuni's jetting was gone through and optimized by Bill Blake at Rockypoint. He made it better, but not as good as these Amal Premieres I bought from him.

Click to expand...

Bonwit
I noted on your original post your satisfaction with your new Amals. I find the single Mikuni does what you like about your Amals all very nicely up until about 100mph, then definitely performance drops off. But I've never like you have, compared the Amals versus single Mikuni on the same bike. Do you notice improvement in acceleration?

Did you sell your Mikuni set up? I was really after a 36mm and presume yours is/was 34mm. But if not sold I'd be interested. PM me if it's not yet sold.

The new MkIII I've just bought is running twin Amals and idle is a bit erratic. But that can soon be sorted. Also I noticed a somewhat heavier throttle movement, to be expected I guess pulling two slides up at once. Nothing that can't be cured. Acceleration was decidedly poor or slow compared to my current MkIII with single Mikuni. But that's all to do with those choking bean cans (I have pea shooters fitted on mine). You can feel when a motor is restricted and it certainly is. My early Norton books claim the bean cans provided no performance decrement. Bullshit!!

Maybe I was a bit exuberant chucking those Amals in the Wingecarribbee river. Shouldn't have thrown my kick starter in there either, but you live and learn.

Phil

Click to expand...

Phil, yes, I notice an improvement in acceleration with the Amals. The other surprise is how well the bike idles, A nice slow lope, even after a short warmup. I never had that with the Mikuni. I'm sure it's because they're new, but hopefully the anodized slides will wear better than the old Amals. As for the throttle pull, it's very light. . . almost too light for my taste. It's become obvious to me that you just cannot compare these new Amals with a set of 40 year old originals.

By the way, I did sell the Mikuni kit, and the new owner is thrilled with it (which I'm glad of). To each his own.

Best

Thanks Bonwit,
Based on what you say, I'll take a punt and buy a set of Premium Amals. My Mikuni certainly can't idle that low but the acceleration aspect I am most interested in. Going this way will save me buying a one into two Mikuni manifold anyway. I'll report on my impressions when it's all kitted up and going. I gather your Premiums are 32mm?

Phil

New Amals Replace Mikuni - What a difference!

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