should i switch to Mikuni Carb ?

Hi all. Some people were telling me to switch to Mikuni Carb on my 73 850 . They say it will run better. My question s will iT?? but will it take away from the Oringality of the bike??

That's like asking what kind of oil to use.. :?

I like my Amals. Others hate them. Take your pick. Yes, you'll lose originality but it's your bike and your choice.

A good new Micki carb is better than two worn out Amals. But if Amals renewed not a lot of difference but the slightly smaller Amals give crisper response to me and have a better bowl bottom profile to view.
A number of pleased users report getting similar advantage of a single Micki carb by installing a single Amal with its pleasing original shape and texture and bragging rights. Buying new Amal or having them sleeved helps support the vendors we depend on.

The best idling 600 rpm, best lugging, fastest most responsive accelerating cycle I've ever experienced was P!! with dual Amals. Only real issue was fire by ticklers dripping to enter points sparking under the Amals.
Off to boil my 10 yr old dual Amal in white vinegar in prep to install back on Trixie Combat for their delightful wide scope of fueling response.

I would never switch to Mikuni's because IMO the Amals work great if they are sorted out and all surfaces trued. Remember that the Amals on the bike are probably 35+ years old and it's not fair to compare an old, gunked up and misused/warped Amal with a new Mikuni.

Amals will idle smoothly at far lower RPM than most anybody sets their idle - mine will idle smoothly at sub- 600 RPM but the idle is set at around 900. No one (as far as I know) disputes the fact that Amals will produce more power than a single Mikuni. Amals are simple and easy to deal with ONCE they are cleaned/trued/rejetted/needled.

But of course one carb means no synchronizing/balancing issues and less to deal with.

Please remember, this is not a perminate change that is non reversable. I Keep a set of amals around and put them on once in a while to remind myself of why I change over in the first place. If it's possibe at all, you got to go a Long, long way to make a Norton not a Norton anymore.

When I got '72 Trixie home from New Orleans and started her I was amazed that she'd been set to idle as 450 indicated on points and dual unserviced in years Amals.
I feared low oil pressure so bumped idle up to 600, but generally set idle close to 1000 for on road stalling avoidance and some charging for lights and power being drained. There is a slight mental emotional advantage of restoring ancient Amals over installing angular utilitarian competition. But either way to allow fine runing Commando is appropriate acceptable.

Have your amal sleeved and it will run as good as a mikuni plus much easier to set up and maintain. RGM sells a nice single amal manifold for reasonable. DO NOT BY A MAP manifold, they are garbage and about 20 dollars more than the nice RGM unit. I like the amal because it still looks like it came that way and it is way easier to tune. air mixture, main, needle jet and a needle and your done. A mikuni doesn't look as nice, but may very well run better with it's bazillion jetting options that you would probably need a dyno to actually utilize and set up correctly. Both options offer tried and true set up so it really comes down to personal preference. I likes me amals.

Just one opinion but I think it is real shame to go single carb on a Commando.

I saw no difference in general street performance and easier to maintain with one carb, not a shame, personal preference. Personally I think two carbs are a waste and as usual to each his own. :roll:

britbike220 said:

Have your amal sleeved and it will run as good as a mikuni plus much easier to set up and maintain. RGM sells a nice single amal manifold for reasonable. DO NOT BY A MAP manifold, they are garbage and about 20 dollars more than the nice RGM unit. I like the amal because it still looks like it came that way and it is way easier to tune. air mixture, main, needle jet and a needle and your done. A mikuni doesn't look as nice, but may very well run better with it's bazillion jetting options that you would probably need a dyno to actually utilize and set up correctly. Both options offer tried and true set up so it really comes down to personal preference. I likes me amals.

Click to expand...

So, what do you know about MAP intake manifolds? Single user problems should not be a death sentence for the specie, maybe your fingers aren't as small as they were 20 years ago? Where do you tink RGM gets their manifolds from? When you go one into two or two into one you lose that straight shot down the gullet with intake length tuning considerations. People that opt for the Mikuni are looking for performance in the low to mid range. A mikuni will get you to 60 faster than any set of Amals (I''m an Amal guy, for the record) and some people like the idea of very easy tuning (with one carb). I agree that a sole Amal still sports the classic look, but internally the Mikuin is far superior to any Amal on the planet, with completely replaceable jets and a chrome slide, and a mounting flange that you can torque right up to, an including stripping of threads without distorting the body of the carb.

All my customs will have twin Amals, with chrome slides and a message to the new owner to ride regularly and to drian the carbs when non-use is anticipated to last more than 3 weeks. Or they can opt for for CNW's fuel injection...

RS

The reason I want to switch

The reason I want to switch is because it's takeing me 6 kicks to start first time out the door and then 3 kicks every time i stop. mikunis should keep me regurlar

Sammy, if it's only because of the number of kicks, look elsewhere on your bike for this problem. If you're after ease of maintenance, a single carb setup is the way to go. If your amals are original try an keep em in tip top shape (as mentioned resleeving and surfaces truing is a MUST, if they are old). I had clapped out amals (1/16 slide side play) on one of my nortons and in the summer in the morning anywhere between 1 to 3 kicks (with points ignition) would get it going. Miks can take time to dial in but one set with electronic ignition and choke on 1 or 2 kicks and she was running. BTW Miks choke is an enrichener which I think is better than the amals choke.
Just my experience.

Before I chucked my original Amals a wise man (Phil Radford at Fairspares) suggested trying a set of newly manufactured Amals. I am so glad I did and I would not even consider running anything but Amal carbs on my bike. They are easy to set up (yep..I said that) and are a big part of the bikes personality. I just completed a 1500 mile trip and the bike, including the dual Amals, performed almost perfectly. There is this odd attitude among many US bikers that all British bikes leak oil, wont start, and will leave you stranded. This is why most modern motorcyclists have a single tool in their kit...a cel phone. They want nothing to do with how their bikes run but are quick to buy chrome horns and leather chaps. Thats cool but not my cup of trea. I ride a Norton Commando because it is unusual and interesting both to ride and maintain. In this era of Japanese and Harley push button motorcycles, I savor the sensation of kicking over my Commando (99 times out of a hundred only once) and having it burst into life.

I also have to stay with the Amals because I bought the shirt

I ran amals for 30 years. Re-sleeved, chrome slides and everything. They worked OK.. Then I put in the PWK/Keihin 32mm flatslides and I will never go back. Being at sea level made it easy to jet them. Sure you can get Amals to work, but you will have to fuss with them constantly.

I never 'fuss' with my Amals. They required nothing on my 1500 mile road trip. In fact, since I set them up with my Trispark ignition they have performed perfectly. Every bike is different but I would say that if you are contantly fussing with anything on a commando, something is either worn out or is incorrectly set up.

To further complicate and confuse ones choices, I throw this into the ring
UFO Flow Optimizer for the Mukuni round slide carb. My bud Wes installed it and I have to say his factory '71 really pulls well, more well than I'm comfortable to ride that fast that quick with clapped out forks and drum brake. If ya already run a Mukuni, then here's a gift for it.

http://www.thunderproducts.com/u_f_o.htm


Too bad Amal didn't offer a brass or bronze or even an Al slide, you could pound around on for great long term function. Trying to put vision out of mind of progressive linked flat slides Jim's developed.

This is probably one of those mine works best threads like oil, tires and electronic ignition vs points. There is no definitive answer to the perfect commando except in our own mind.

Amal chrome brass slides:

http://www.amalcarb.co.uk/ProductDetail.aspx?id=37428

Amal Forged Alloy Hard Anodised Slides:

http://www.amalcarb.co.uk/ProductDetail.aspx?id=37410

I have owned my Norton 850 M11 sence new, have done well over 120,000 miles and have always had Amal carbs, have just replaced ( 20 years ago now ) the orginal Amals with new ones, even with worn slides the old one still ran good and they even idiled, and it always 1 kick to start, if it took more there was somethink else that was at fault, the Amals have out lasted points, 2 boya electronic igntions ( 1 died from major fuel fire ) and they even survied the major fuel fire, I have just rebuilt the bike and now running a Joe Hunt Maggie and is even a lot easyer to start and runs great with the Amals and the new Amals have got about 20.000 miles on them now, I'm no carby expert but I have never had any problems with turning and balancing the carbs, my motor isan't a standared motor has SS cam grind, major head work, balanced crank and open exhaust system, with the right jets the Amals work great and so simple to work on and they look good with K&N air filters.

Its like any thing that is over 35 years old things do wear out, I replaced my old Amals 20 years ago but I still call them my new Amals as they aren't the old ones, the Norton has sat for a few years before I got the urge and money for the rebuild and all I did was to pull them down and replace all the jets and needles
and a good clean out, so I think I will stick by them as they have worked well for me and I know them inside out.

Hope this helps.

Ashley

Same here, tuned motor, Amals run brilliantly. Only problem I had was the needle jets wore out once. I suppose I have approx. 15000mls on my new bodies & slides.
I will not put anything japanese on my Norton, I personally find it a sacrilage (think I spelt that right). I also get dismayed with seeing a single carb. on a twin carb. bike. Only my opinion (& probably a few others) of coarse.