Aftermarket carbs
Road Captain
Joined: Jan 2007
Posts: 645
Likes: 216
From: Minneapolis
Yes, I have an Innovate LM-2 data logger. If you are thinking of getting one, I just want to warn you; It's addictive, and not in a good way.
Ultimate HDF Member
Joined: Aug 2012
Posts: 6,470
Likes: 4
From: on the road
Well armed with this tool you could get where I couldnt quite quickly.Even the local dealerships dont like to mess with the carbs due to not having a canned recipe for success so to speak
Road Captain
Joined: Jan 2007
Posts: 645
Likes: 216
From: Minneapolis
I can tune a Mikuni so quickly and so well with the meter, I don't have a single friend who still runs a CV or S&S on their bikes.
I mark the throttle with a piece of tape at idle, 1/8, 1/4, 1/2, 3/4 and WOT. Warm up bike, adjust idle mixture, go out and check the a/f at each throttle mark and make the adjustments to the carb. It's pretty easy. Not so easy reading plugs and adjusting blindly.
I don't want to jack this thread, so to the original poster:
Again, both are good carbs, but if tuned properly, the mikuni should get you better mileage and crisper throttle response. Is it worth the cost to change from a super e that is working well already? Only your pocket book will answer that question for you. I've sold several Super E's to strangers on ebay in the last few years, but I've only sold 2 Mikuni HSR's, and they both went on close friends bikes. If that tells you anything.
Road Captain
Joined: Sep 2007
Posts: 525
Likes: 2
From: San Diego
Not to offend anyone who chooses S&S, but there is no comparison between a Super E and an Mikuni HSR. The comments about adjustments are most likely coming from someone who doesn't truely understand carburation and/or know how to adjust them properly. The S&S simply does not have the number of tuning circuits (in stock form) as the Mikuni, and cannot be as accurately tuned. In tuning the carb, with the Super, you get what you get; with the HSR, you get what you want.
If you put a Mikuni on your bike, and tune it properly (they also have a great tuning manual), it will be the best carburator you have ever owned on a motorcycle. The throttle response is crisper, the accelerator pump is 10x better, the midrange adjustments work, the WOT main jets are easy to change, the enrichener circuit (which also works great on the S&S) make starting a breeze, and you will get better fuel mileage than you ever did with your tractor carburetor.
I understand carburetors, transistion circuits, air bleeds, etc. and I have the a/f monitoring equipment to verify and see how they are working. I can assure you the Mikuni is the better choice.
I have run S&S Super E's on both my Evo and Shovelhead. I desperately wanted to keep the Super E on my Shovel. It's foot print is smaller, it looks good, and it has that classic American vintage feel. I ended up with the Mikuni in the end, again, and it's a huge hassle to run one on a shovel (because of the oil line between the heads).
The real problems with the S&S show up when running drag pipes. You have enough adjustments to still make it work well with the HSR in that situation. Don't get me wrong, with decent exhaust mufflers, you can certainly have a good running bike S&S Super, I know I have. But when you get serious about having the best possible running bike, the Mikuni is what I spend my money on.
I don't know what year bike you have, but 2 of mine have the dash mounted chokes. I modified my setups to use the stock location with the Mikuni. If you have a newer bike, you can use the stock location under the left tank, or there are brackets to mount it right on the carb.
Good luck whatever you decide.
If you put a Mikuni on your bike, and tune it properly (they also have a great tuning manual), it will be the best carburator you have ever owned on a motorcycle. The throttle response is crisper, the accelerator pump is 10x better, the midrange adjustments work, the WOT main jets are easy to change, the enrichener circuit (which also works great on the S&S) make starting a breeze, and you will get better fuel mileage than you ever did with your tractor carburetor.
I understand carburetors, transistion circuits, air bleeds, etc. and I have the a/f monitoring equipment to verify and see how they are working. I can assure you the Mikuni is the better choice.
I have run S&S Super E's on both my Evo and Shovelhead. I desperately wanted to keep the Super E on my Shovel. It's foot print is smaller, it looks good, and it has that classic American vintage feel. I ended up with the Mikuni in the end, again, and it's a huge hassle to run one on a shovel (because of the oil line between the heads).
The real problems with the S&S show up when running drag pipes. You have enough adjustments to still make it work well with the HSR in that situation. Don't get me wrong, with decent exhaust mufflers, you can certainly have a good running bike S&S Super, I know I have. But when you get serious about having the best possible running bike, the Mikuni is what I spend my money on.
I don't know what year bike you have, but 2 of mine have the dash mounted chokes. I modified my setups to use the stock location with the Mikuni. If you have a newer bike, you can use the stock location under the left tank, or there are brackets to mount it right on the carb.
Good luck whatever you decide.
The S&S carb is just in my comfort zone, like an old friend, I have set up so many of them and it's so easy.. No doubt the S&S is a very capable, reliable, carb..
I recently swapped out an S&S super E W/Thunderjet for an HSR 45 Mikuni. Initial impression is the same as you posted, better throttle response and milage. I haven't played with it too much as it ran pretty well out of the box and is easily matching the performance of the S&S but with the added benefits mentioned.
Only thing I am unsure of yet is reliability and the ability to fix it on the side of the road if a problem comes up like debris blocking a jet.
The main reason I have used S&S is that I can drop the bowl on the side of the road in a minute with hand tools.. The mikuni seems to be the same (unlike the CV) that has to be removed to fiddle with..
Time will tell but so far I am impressed with the Mikuni..
Seasoned HDF Member
Joined: Aug 2008
Posts: 5,081
Likes: 2,159
From: Ohio
Also tune Mikuni's with a Wego 3 data recorder, can't tune a carb per cell like a EFI but able to get low, cruise, roll on and WOT perfect with a Mikuni so can back up Mrlexus. CV's can be tuned as well but dump excessive fuel on the accellerator pump side and a carb that is very flexable while supporting 100 hp, had no problems with a modded CV before I went to a Mikuni 45.
Havn't never messed with a S&S but my riding buddy has a flat spot in his but too stubborn to hookup equipment to fix it, his view is a flat spot is common with a S&S because of the jet transition design, don't know enough about them to debate it. His S&S will pull hard at WOT, the 80" incher will embarrass alot of bigger engines.
Havn't never messed with a S&S but my riding buddy has a flat spot in his but too stubborn to hookup equipment to fix it, his view is a flat spot is common with a S&S because of the jet transition design, don't know enough about them to debate it. His S&S will pull hard at WOT, the 80" incher will embarrass alot of bigger engines.
Road Master
Joined: Jan 2008
Posts: 1,187
Likes: 8
From: Montgomery, AL
You wanted opinions, I'd just search for a used cv and run it. My cv has given me no troubles in many miles.
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Road Master
Joined: Nov 2012
Posts: 794
Likes: 1
From: Alvin TX
My 94 came with the Cv still run great set forsea level go out west to NM & no worry in the high mountains there ,took the efi off my tc & put a cv of there same deal no trouble at any level
Cruiser
Joined: Apr 2012
Posts: 130
Likes: 7
From: Seymour Indiana
I have not experienced any of the float problems you speak of, but do run filters on 3 of the 4 bikes I have mikuni's on.
In regards to the drag pipe situation: The S&S has an idle circuit, the intermediate circuit (which includes the air bleed) and the main circuit. The problem with drags is generally in the 2000-3500 rpm range, right where that intermediate is doing all the work as you are rolling on the throttle. The only 2 things you can do are to change the intermediate jet size, and/or change the air bleed to alter the time when the main takes over, hoping you can get past the rich hiccup without making the main too lean. Air bleed tuning is pretty much impossible for the average joe if you don't have A/F meters or are working on a dyno. At least S&S changed to an adjustable air bleed around 10 years ago, so you don't have to drill out the air bleed and pray you don't f it up. That's the reason people add the thunder jets, to get that extra tuning ability.
The Mikuni allows you to raise or lower the needle (and change needle diameter) to lean out the drag pipe problem area better than the S&S. Off the shelf Super vs off the shelf Mikuni, you simply have more circuits you can adjust to get it dialed just right.
If you aren't going to spend the time to work with all the circuits on the HSR, then you probably will have better luck with an S&S and just adjusting the idle mixture, intermediate jet, and main and simply riding it. There is a big range where an engine will run just fine without rich stumbling or lean popping, 11:1 to probably 15.5:1
The S&S (without all the extra **** hanging off it) simply cannot deliver as flat of a fuel curve as you can get from the Mikuni HSR. It's that flat curve and the ability for it to change (and still stay flat) with throttle opening change is what makes the bike run as good as it possibly can. It allows you to achieve max HP from your combo and at the same time get max fuel mileage.
Can you get an S&S Super E to run good, start good, and be a good carb? Absolutely, and there are more of them out there than you can shake a stick at.
I've done the drill. Slap on the a/f meter and data monitoring gear, and spend as much time as I needed to get the Super to run as good as I possibly could. Changing jets, air bleeds, idle mixtures, and testing at different throttle positions. Then swithed to the Mikuni and did the same thing. The mik will just perform better in the end.
I honestly could care less what carb anyone runs. I try to tune my carbs so they work as close to fuel injection as they possible can, and after more hours invested in tuning than I would care to admit, I have found the Mikuni a superior carb to the Super E; if you take the time to tune it like it is suppose to be tuned. The interweb is full of opinions, and that's fine. I'm just sharing what I have found, working with both carbs the OP mentioned.
It all boils down to what you are looking for and what you are trying to accomplish. The good news is, both brands still command a decent used price, should you decide you chose unwisely...
In regards to the drag pipe situation: The S&S has an idle circuit, the intermediate circuit (which includes the air bleed) and the main circuit. The problem with drags is generally in the 2000-3500 rpm range, right where that intermediate is doing all the work as you are rolling on the throttle. The only 2 things you can do are to change the intermediate jet size, and/or change the air bleed to alter the time when the main takes over, hoping you can get past the rich hiccup without making the main too lean. Air bleed tuning is pretty much impossible for the average joe if you don't have A/F meters or are working on a dyno. At least S&S changed to an adjustable air bleed around 10 years ago, so you don't have to drill out the air bleed and pray you don't f it up. That's the reason people add the thunder jets, to get that extra tuning ability.
The Mikuni allows you to raise or lower the needle (and change needle diameter) to lean out the drag pipe problem area better than the S&S. Off the shelf Super vs off the shelf Mikuni, you simply have more circuits you can adjust to get it dialed just right.
If you aren't going to spend the time to work with all the circuits on the HSR, then you probably will have better luck with an S&S and just adjusting the idle mixture, intermediate jet, and main and simply riding it. There is a big range where an engine will run just fine without rich stumbling or lean popping, 11:1 to probably 15.5:1
The S&S (without all the extra **** hanging off it) simply cannot deliver as flat of a fuel curve as you can get from the Mikuni HSR. It's that flat curve and the ability for it to change (and still stay flat) with throttle opening change is what makes the bike run as good as it possibly can. It allows you to achieve max HP from your combo and at the same time get max fuel mileage.
Can you get an S&S Super E to run good, start good, and be a good carb? Absolutely, and there are more of them out there than you can shake a stick at.
I've done the drill. Slap on the a/f meter and data monitoring gear, and spend as much time as I needed to get the Super to run as good as I possibly could. Changing jets, air bleeds, idle mixtures, and testing at different throttle positions. Then swithed to the Mikuni and did the same thing. The mik will just perform better in the end.
I honestly could care less what carb anyone runs. I try to tune my carbs so they work as close to fuel injection as they possible can, and after more hours invested in tuning than I would care to admit, I have found the Mikuni a superior carb to the Super E; if you take the time to tune it like it is suppose to be tuned. The interweb is full of opinions, and that's fine. I'm just sharing what I have found, working with both carbs the OP mentioned.
It all boils down to what you are looking for and what you are trying to accomplish. The good news is, both brands still command a decent used price, should you decide you chose unwisely...