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OK, here's the scoop. I have decided not to do any cylinder work (for now). At present, I have an S&S Super E carb, and my mechanic has recommended switching to a Mikuni 42mm.

What will I gain by switching? It seems like quite a bit of money, so I thought I would ask y'all what the pro's, con's, and differences between the two carbs are.

I have an 80" Evo with ported heads, single-fire ignition, Andrews EV-27 cam, and Longshots cut down to the baffle mounting.

Is it worth the money to go with the Mikuni, and why...

Thanks for your help!!!!!!!!
 

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I think your are well off with the S&S using the nonperformance exaust.
I would use the Mikuni with a two into one system myself.
 

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Are YOU happy with the S$S? If so, leave it there. It is a very simple carb and usually delivers satisfactory results. The S&S is a fixed venturi, meaning the air is traveling through a venturi that is the same size all the time. The Mikuni is a variable venturi as the slide lifts adjusting the size of the opening that the air travels through. A slide carb typically will give a higher air speed as the air is moving faster through the smaller opening and better throttle response at some throttle positions but I wouldn't buy the Mikuni to replace the S&S that is already in place unless you are looking for the response and money is not a concern.
 

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Can't comment on the different performance aspects ot the two carbies but in my opinion the s&s tear drop air cleaner is still the best looking ever made.
 

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Is it worth going with the Mikuni? Only if you want to pay for your mechanic's next few cases of beer. ;)

My personal preference is the S&S... that's the only carb I'll use now. It's one of the simplest, most reliable, and easiest to tune high performance carbs on the market. Very few moving parts and once you get it tuned, you won't have to mess with it again. Over 90% of drag bikes use them for good reason. They work! Make sure you get a K&N air filter for it, though. They make the best filters available. Anyway, if it's working for you, you might want to leave it on the bike. It performs just as well as the Mikuni, IF it's tuned correctly. They tend to cause a bit of hesitation off idle, but that can be easily eliminated by adjusting the accelerator pump and installing the Yost Power Tube. Worked for me... no hesitation at all now, EVER! I don't even have to blip the throttle anymore before pulling out from a light. The S&S will handle just about anything your engine can dish out. Why spend $$ if you don't need to, IMHO? :) -2$en#e-
 

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baggersport said:
The S&S is a fixed venturi, meaning the air is traveling through a venturi that is the same size all the time. The Mikuni is a variable venturi as the slide lifts adjusting the size of the opening that the air travels through. A slide carb typically will give a higher air speed as the air is moving faster through the smaller opening .
lust a little confused here
and not trying to step on any ones toes
so correct me if i am wrong and not understanding this correctly

don,t the s&s have a butterfly that opens adjusting the the size of the opening that the air travels thru?

and in this case the s&s e has a fixed 1-7/8" venturi
and the 42 mm mic have a fixed 42 mm venturi
with niether really having a varible size ventrui
this is what i have found over the years testing the 2 carbs

all carbs beeing the newer modles bone stock out of the box with no mods

the mic normaly flows a little higher air velocitity with a finer fuel mist due to the neadle adjusting fuel flow more evenly for better throttle response
but less air at wot = (wide open throttle) creating less horspower


where the s&s normaly flows higher volumes of air at wot creating more horsepower
this is due to the tappered throte


the new s&s shorty carbs have a adjustable air bleed like the mic has
giving the tunner the ability to adjust the rpm that the jets transition in so the flat spots of the past are gone with s&s shorty carbs

now the s&s can be modified for better throttle response and more horspower
where the mic takes a lot more time and money to modify to get the horse power up

any way this is how i unsderstand and see things using my flow bench and dyno wich are a little on the older side like me so maybe things have changed
 

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SNUFFY said:
lust a little confused here
and not trying to step on any ones toes
so correct me if i am wrong and not understanding this correctly

don,t the s&s have a butterfly that opens adjusting the the size of the opening that the air travels thru?

and in this case the s&s e has a fixed 1-7/8" venturi
and the 42 mm mic have a fixed 42 mm venturi
with niether really having a varible size ventrui
this is what i have found over the years testing the 2 carbs

all carbs beeing the newer modles bone stock out of the box with no mods

the mic normaly flows a little higher air velocitity with a finer fuel mist due to the neadle adjusting fuel flow more evenly for better throttle response
but less air at wot = (wide open throttle) creating less horspower


where the s&s normaly flows higher volumes of air at wot creating more horsepower
this is due to the tappered throte


the new s&s shorty carbs have a adjustable air bleed like the mic has
giving the tunner the ability to adjust the rpm that the jets transition in so the flat spots of the past are gone with s&s shorty carbs

now the s&s can be modified for better throttle response and more horspower
where the mic takes a lot more time and money to modify to get the horse power up

any way this is how i unsderstand and see things using my flow bench and dyno wich are a little on the older side like me so maybe things have changed
Ya hit the nail right on the head! There's nothing wrong with the Mikuni, IMO, but the S&S is a time-proven design that has evolved over the years. I remember when they didn't even have an accel pump, and they still worked great! Yes, they cost a little more, but it's worth it for a simple, reliable, high performance carb. If someone is spending many thousands on a bike and chrome goodies, then spending another $300+ on a carb shouldn't be any problem.

I tried the Mikuni and it works very well, but they can be a pain to tune perfectly. I can dial in an S&S in about 5 minutes on the dyno, and if you are a little off, they will still run well. It's also very easy to open and clean out of you get crud in it while on the road. The only thing they haven't improved, except for making it adjustable, was the enricher, which I almost never use since it fouls plugs so fast.

I don't know... maybe the bad experiences I've had with other CV carbs (like the SU Eliminator) turned me off to them. :) I'll stick with the S&S. They've never done me wrong. :wavey:
 

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Get a different mechanic that can dial in your S&S and not try to fix a problem by bolting on a Mikuni.

I run a Mikuni 42 on my FXR and an S&S E on my FLHT. Both 80" evo's. Both came on the bike when I bought them used.

The FLHT is bone stock except for the S&S.
The FXR I installed a Crane cam, adj. pushrods, had the heads ported, single fire igintion and pipes.

I've rebuilt the Mikuni and rejetted it and rebuilt the S&S, the jetting was fine.

I'd keep either one and dial it in.

For what it's worth, I like the S&S better...
 

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ToddM said:
Is it worth going with the Mikuni? Only if you want to pay for your mechanic's next few cases of beer. ;)

My personal preference is the S&S... that's the only carb I'll use now. It's one of the simplest, most reliable, and easiest to tune high performance carbs on the market. Very few moving parts and once you get it tuned, you won't have to mess with it again. Over 90% of drag bikes use them for good reason. They work! Make sure you get a K&N air filter for it, though. They make the best filters available. Anyway, if it's working for you, you might want to leave it on the bike. It performs just as well as the Mikuni, IF it's tuned correctly. They tend to cause a bit of hesitation off idle, but that can be easily eliminated by adjusting the accelerator pump and installing the Yost Power Tube. Worked for me... no hesitation at all now, EVER! I don't even have to blip the throttle anymore before pulling out from a light. The S&S will handle just about anything your engine can dish out. Why spend $$ if you don't need to, IMHO? :) -2$en#e-

I am quite fond of the stock CV, when modified of course! I buy em at swap meets real cheap all the time, and they are almost always brand new take offs. Man, a 1998 sportster needle a tweek here and there and these carbs perform flawlessly. These are for stage one upgrades mind you.
 

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I had a CV carb in my 99 evo, and it refused to ever be dialed in correctly, and if it was it wouldn't last long, that is if it ever was. Also had a yost power tube in it. BS. Got a S&S Super E, got it dialed in and have never ever had any problems with it. Mikuni shmuni. Stick with the S&S or get another wrench.
 

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Discussion Starter · #12 ·
baggersport said:
Flamed, here is one of many previous posts;
http://www.v-twinforums.com/forums/showthread.php?t=26279


I searched the forum under "mikuni", if you should do the same, there's a lot of information on this already.



:beatdh:
Thanks eveyone....

Bagger, sorry to bore you.

I did a search, but I have found that specific questions get specific answers. Didn't mean to "beat the dead horse".
 

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ToddM said:
I don't know... maybe the bad experiences I've had with other CV carbs (like the SU Eliminator) turned me off to them. :) I'll stick with the S&S. They've never done me wrong. :wavey:

The last Mikuni I has was a flat slide, not a CV...:dunno:
 

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MegaGlide said:
The last Mikuni I has was a flat slide, not a CV...:dunno:
Right, the older ones weren't CV carbs. Those one's were just using a slide instead of the butterfly to control the size of the venturi. That slide was connected directly to the throttle cable.

For those who don't know, if it has a cylindrical piston (like the SU) or a slide moving up and down by air pressure, then it's a CV.
 

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Flamed, You're not boring me. I was trying to help as there is multiple posts already out there. If you don't find any good answers, ask the question. Sometimes the threads will start to deteriorate into a bitchin match of opinions and that won't usually help the original post. I would be happy to talk carbs with you until you feel you are an expert (not a joke), just not on a thread. Feel free to contact me.


Bean


:D
 

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Stock CV carbs

Hey, anybody got the un modified take off CV carbs from lets say 96 or so up to 98, and doesn't want them cluttering their bench PM me with a resonable price. I pick em up at swap meets all the time and make em run beautifully for stage one applications. I'd be happy to take em off your hands!

Rickr01
 
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