The following is the text from a email from a customer that we recently received, and my subsequent response that we would like to share with you.
This is the original email:

Hello FTZ,
I was wanting to know if there is anything you can due with these carbs They are running way to rich But I was running a 07 Yamaha with level 2 head work now I am running a stock 08 Honda cbr600rr
I copied this off a email to me from another builder about these carbs:

"Hi Steven,,
Received your carbs today,, They were built by FTZ. They basically ruin a good set of carbs. They drill out the main metering passageway to an oversize that is way to rich , because of this modification that do . It makes it impossible to correct the rich condition . they also do mods to the high speed air bleed circuits that are irreplaceable and impossible to correct also ,,
The bad news is that there is nothing I or any other carb builder can do to correct what they have done to the carbs to try and make the carbs " Leaner" and perform properly on Alcohol. They will always be tooooo rich.
Let me know what you would like to do. I did a minor teardown to inspect the condition and what had been done to them, I saw there is nothing I can do to rectify their work, I have boxed them back up to ship back to you."

This was my response:
Hi Steven,
This is Jon Fitzpatrick and I am very glad you sent me the body of text from this "other builder", It is good to know what people are being told by others- right or wrong. First off, frankly I would be interested to know what prompted a guy to send a set of carburetors to someone that did not design or build them in the first place, but worse yet doesn't even know how they work. If you happened to have called here and heard something you didn't like I would like to know that so that I can fix that.
I normally avoid having much comment about other "builders", but if we get our toes stepped on enough we have been known to "push" back. We try to fight this "smoke" with the facts, (although it sure seems a lot of people prefer the "smoke"). So here obviously this "Guru" is assuming that because the main nozzle is bigger than most other carbs then they must run rich. This is about like mathematics on a 3rd grader's level- sorry, it just gets a
lot more complicated than just that. He is referring to the fact that we ream the main orifice nozzle about ten thousandths larger than most other guys do. Please understand that every carb conversion we have seen done by others is a copy or similar variation on the mods done for years by Rick Odum, and others before him. All pretty much the same, except ours. When we first built R6's we also used these carbs but I saw much room for improvement and I did not like the idea they often needed to be choked with an airbox to pull fuel well. So we locked ourselves in the dyno room for several weeks and perfected our current setup that we use which makes much better power.
BTW, had this "guru" bothered to measure the needle he would have found that it is approximately ten thousands larger as well- and beyond that- had he calibrated the area difference between the needle diameter and the orifice diameter he would have seen that it is nearly exactly the same. But even that is too simplistic as there are several other modifications that only we do to the carbs that others do not, that affect things greatly. We are the first, and far as I know the only ones, that have developed a setup utilizing the air correction system, which is usually blocked off in other guy's conversions. The air correction system was designed in by the Japanese on their modern motorcycle carbs and it the biggest improvement over older motorcycle and automotive carbs. The A/C system actually help keep the mixture from getting overly rich, particularly at high rpms- which is the tendency for most carbs to do. Had this "Guru" had done any actual testing with air/fuel ratio data acquisition systems as we have, this becomes obvious. We have worked this setup out so well on the R6 carbs to even promote a positive comment from Mike Dicely from Hyper, a diehard fuel injection guy, as he was surprised how flat we could get this fuel curve with our a of carburetors, something they try hard to achieve when mapping their electronic injection. This won't happen with these other guy's carbs. The fact is that our carbs actually run leaner on top than others, while giving more fuel when needed at the torque peak. The result is our carbs tend to pull much harder off the corner and finish out the straightaway very strong and also seldom require a jetting change. And we have had dozens and dozens of people that have testified to this over the years. Many say they cannot believe just changing a set of carbs can make such a big difference.
So rather than soliciting advice from somebody that obviously doesn't even understand how modern carburetors function, I would suggest sending them to us so we can have our carb expert Ryan look them over to see if everything is as it should be. We will call you with the findings before starting on any work needed. I suspect that if indeed the carbs are clean and haven't been monkeyed with, that all you may need is a simple change of the air correction jets- As a stock motor will not pull as hard on the same jetting setup as our modified motor with Level-2 portwork, so my guess is it is actually running too lean if anything. That would better explain the popping you mentioned.
It is really a sad fact is some of these "other builders" feel the need to talk other people down, obviously to make them selves look better, but I suspect often to hide their own inadequacies. And lately it seems like there is a new engine builder every month- and of course they know more than everyone else, or they at least will tell you that, despite their short history. And sooner or latter some good driver with a good car will win some races on some little track somewhere- and before you know it? Bam! another "Guru"... Of course they can't match our record of over 25 years of winning National Championships & titles, and many of the biggest races held nearly every year, so some these guys resort to back-stabbing and running others down about things that that either don't understand, or don't have the skills or equipment to do themselves. Our showing at the I-30 Nationals last year, where we had 5-6 very fast cars there every night, all in different chassis's- going to the front on a race track that demands torque and horsepower over a wide power band-that should prove something to anybody that is paying attention- as nearly all the fast guys from all over the nation where there.. I know that is just one example, but it is one of many. (see www.ftzracing.com. for some darn good I-30 racing video)
Adding to the issue is so many people racing today don't have a good understanding of what actually makes horsepower in a modern engine, so to enable them to sort out the "good shit" from the "bullshit"- which leads them to follow advice from some guys at the track, or these amateur builders, etc. A good example is anyone that thinks a motor is "built as good" as say our Level-2 ported motors- when all they are getting is a "sandpaper" port job with some stock valves, and maybe a different set of pistons or some other hi-dollar parts in the bottom end. That is not our idea of building a motor, heck you may as well do that yourself. One major point that is often overlooked is called
"BREATHING". Simply put, the more air & fuel a motor pumps in- the more power it will make. You don't get good breathing with stock valves and amateur port jobs- forget that. This is why our 600cc motors will often beat the competitions 636cc motors. Another major point is a properly built race motor (or carburetors or even an exhaust system) is not just a collection of parts, but more important is how those parts are put together. Nearly every time we get a competitors motor through the shop we find grossly improper clearances and worn parts that should have been replaced. No exaggeration here, it is scary- but it is true.
I will finish my little rant here by saying thanks again for sending this to us and giving us a chance to at least respond, and sorry for the long response, I do get a bit aggravated seeing people suck up all this "smoke" without even looking into the facts, at least you had the good sense to seek the other side's perspective.
As far as your Honda, we have many guys running our R6 carbs on the RRs with very good results- many previously ran fuel injection and are now very happy with the power and the ease of tuning. I have full confidence they can be made to work great for you as well. If you can send the carbs in to make sure they are okay, we should be able to turn them around in just a couple of days.

Now please understand-- This was only a conversation between me and a customer that I decided to share with browsers of our web site. It is the same conversation I have had hundreds of times trying to get people to simply stop and think- and not to compare Apples to Oranges. A sales pitch?- well sure.... We are in business to sell things and win customers, and the world wide web can get this out to many more people than we can ever call up and talk to. But we see many people buying into the idea that a set of carbs, or an engine built by Builder X, Builder Y, and Builder Z are all pretty much the same and will run pretty much run the same- and that just is not true. This was NOT an attempt to make ourselves look better by making someone else look worse- I hate that trait in some people. Remember this was in response to someone running our work down. And I am not saying we are the only ones that know "anything"; This is only a plea to let us show you what all we do, and how different it is, and what a difference it can make.
Brand X, Y,and Z stuff all can win races, (as well as bone stock motors) when the situation is right, especially if that is all there is at a certain track. It is that kind of sport, and the motor is just one piece of the bigger puzzle. But when you don't want to compromise, then call us up. Travis Senter is a guy that does not want to compromise, one look over his racecar- or his record- will tell you that. He has recently stated his hardest pulling motor- and the easiest to pass cars with, is with is his 5 year old +2 mil "old style" R6 with carburetors. Just ask him.....
Thanks for reading,
Jon

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