Mikuni or S & S "Super E?"?

Question

Which carburetor performs better on evolution motors-the Mikuni 48mm or the S & S Super E?

Answer 1

I used to swear by the S&S ,but around 5 years ago I bought a crate motor ( T.P.) that came with the Mikuni.
I now prefer the Mikuni to the S&S and am running the HSR45 on my 121" and on the old ladys 100".
Nothing wrong with the S&S I just seem to get better power and plug reads with the Mikuni.

Answer 2

For just about any use you have for a carb, a Mikuni is better. You can tune a Mikuni to run anyway except upside down. A S&S - good luck. You have a minium of 6 tuning stages on a Mikuni, 3 on a S&S. The old Harley theory of a bigger engine, a bigger carb falls apart when you look at the port/valve size. It takes a lot of guys a long time to figure that it does no good to install a bigger carb without doing matching port and vlave work. UNTIL YOU GET TO MORE THAN 4 CYLINDERS, YOU NEED THE SAME SIZE CARB, WHETHER YOU HAVE 1 CARB OR 4!!!!! Only 1 intake cycle occurs at a time until you get over 4 cylinders. A standard EVO port at the head is 1.6 in. Carb should also be 1.6 in. This works OK with stock valves. Go larger valves, open ports to match. Smallest area of port should be just upstream of guide, should be aprox 90% of valve throat area. Port area at start of port should be same as throat area. Long taper down, short taper to throat. Carb should be same bore as start of port. Now, a lot of you 'experts' may not agree with me on this, but a whole lot of Harleys do. Calculate air velocity through the carb, and port. Should not exceed 350 ft/sec at full throttle. Should be at least 300 ft/sec at full throttle. IN THE CARB THROAT. A big S&S on a stock port, will have a lot less, and very poor throttle response. If yo doubt this, just set up an engine using the above specs, and see what you find. A customer grinning ear to ear.

Tomcotexas

Answer 3

My first question to you is what kind of Evo motor are we talking? Like stock 80ci or are we talking some stroked out beast with a high lift cam? If it's stock, seriously there is no need to change the stock carb. A dynojet kit works (the $74.95 one) just fine. Even if you do change pipes and air cleaner. Now if you've built yourself a fine piece of machinery there then I would say Mikuni. Instead of giving the opinion and bragging about numbers, let me tell you why. S&S carbs yes, great rep, great name. Problem is there is very little midrange tunability on one. It's mostly slow and main circuit adjustments. Nobody rides in the throttle range of your main jet (3/4-wide open) for any length of time. You need something with a good slow and midrange. Midrange tunability (intermediate) controls from 1/4-3/4 of your throttle which is where you ride anyways. A Mikuni has a better designed venturi (the sideways hourglass look that drives your air/fuel mixture into your motor) and is much easier to tune. They usually come with a good assortment of the jets you need whereas S&S is a very touchy carb. You don't get as many jets, not many dealers carry them and they're pretty expensive. Not to mention, finding someone who can actually work on one if you end up needing help is like pulling teeth. You always hear "a carb's a carb" and that is serious b.s. I know the old school guys will hate me for saying Mikuni but I think it's a little more reliable and easier to install.
I've always had awesome luck with Mikuni. Next thing and you may have reasons for this but I'd wonder why so big? The best way to get killer performance is an open intake and the smallest carb you can use without starving your bike. The smaller the carb, the more pressure you build up and the better fuel atomization. Your bike works on engine vacuum. Vacuum is created when air passes through your intake, picks up the fuel from the pilot circuit on the intake side and atomizes the fuel to deliver on top of your pistons. If you go too big on the carb, the fuel is not atomized, leaving raw fuel dumping in your motor, causing carbon buildup on your internals and leading to lean conditions,fouling plugs, pre-ignition or detonation.
My advice is use a carb that's best suited for the performance you have. Too many people want to mix components or listen to their buddy because he can change a spark plug or read a magazine and think that's gospel. If you need more fuel and you can't get any bigger jets in your stock carb, you've exhausted all options, then start smaller. I know bigger, better, faster. Not with carbs. Don't drill your stock carb jets either. That leads to irreversible crappy performance.
I'd say start with a 42 if it's stock or you've only done pipes and intake. Work up SLOWLY on the jets there. Definitely read the book that comes with it. There's thresholds for everything. If you've built a powerhouse, go with a 44. But I don't think I'd even touch a 48. I have yet to find a motor that needs it.

Answer 4

Mikuni

Answer 5

S & S , are 30's technology that work ok if you are drag racing. but as anyone knows by looking at the computer in front of you technology has come a long way in 70 years. The Mikuni is by far mor tuneable and better ridability. To the guy that says he can tune an S&S bring your best tuned s&s we can pull that and a mikuni i tuned and i gaurentee the mikuni will have better #s, be more fuel efficient., ride better on the road, and start beter in the cold. if you ask me though efi is way better. but for your question the mikuni is at least 50years of mechanical improvement better.

Answer 6

Not much experience with Mikuni's, but S&S's are easy to tune, and the "E" model gives good lower and mid range response.
Once you go over 100 CI's, you'll need a "G" model S&S to feed those inches, but you'll lose some of the lower/mid range response of the "E". Because of this, many people riding right at the 100 CI borderline will still use the "E", while giving up a little top end of the "G".

Answer 7

S&s Super E Tuning

Answer 8

mikuni seem,s to be a little more reliable.....but for power....a well tuned S&S is hard to beat.

Answer 9

S&S it is easyest to tune