Carbs

[airborneXS]

Well im tired of fiddling with these oem carbs...ive heard that there are many different options and was just wondering yall's opinions of different things you have tried...
I spoke with a guy the other day that said he used to buils xs's in california in the 80's, and after trying dozens of different combinations he switched to another japanese model of carbs, he said he thought they were keihin but couldnt remember, and after switching them out that it was a night and day difference...

[TheFrugalTech]

Do you have any other mods you don't have listed?
If not, I think you may be running a little rich.
The stock carbs are definitely adequate, once properly tuned.

[Rasputin]

I guess I have to ask what do you have for sale? Is it an entire bank of carbs, parts or are you just venting? I am in the market for a cheap set of XS carbs.

[airborneXS]

just looking to try something else out...im going to keep my oem carbs for now...i ride her daily so until i get something figured out shes just going to have to manage...

[airborneXS]

anyone? carb ideas? zrx carbs is something ive heard before...

[airborneXS]

if im running rich, does anyone have any smaller jets i can borrow to try out some different settings?

[IanDMacDonald]

I'll be the first to question your main jet size. Stock I believe is 137.5. I am familiar with Mikuni MKII's as well as the BS34's. I cannot recall if the BS34's have an adjustable needle clip, but, I would go back to stock main jets, and then adjust the clip down one or two positions. There is absolutely no reason to go up two whole main jet sizes just for some pods. That's my experience doing the carb tuning I have done.

[BA80]

I agree whole heartedly Ian. The first thing people want to do is change jet sizes if the thing ain't running right.

If it ain't running right it's probably the fault of the person working on it. Not the jets.

Stock jets work just fine in mine. I don't run pods but I have aftermarket exhaust. A little lean at top end but I don't spend much time up over 100mph anyway.

The pods should lean it out rather than richen it anyway.

[Rasputin]

I agree whole heartedly Ian. The first thing people want to do is change jet sizes if the thing ain't running right.

If it ain't running right it's probably the fault of the person working on it. Not the jets.

Stock jets work just fine in mine. I don't run pods but I have aftermarket exhaust. A little lean at top end but I don't spend much time up over 100mph anyway.

The pods should lean it out rather than richen it anyway.

I had to up my pilots by one size to get rid of the stumble from the pods. Yes they do run leaner and so one may have to run a bigger jet to compensate for the lean condition.
I am also lean on the top end with the jardine spaghetti system which I may change one day, but like you say I seldom spend long periods over 100mph.
I would advise against moving the needle from its middle position as I have always found it to be the best spot for any configuration I have so far run.
Everything from fuel used to elevation may differ for others but that is my 2 cents worth.

[DGXSER]

Note he also list a "home made 4-2" exhaust. If it has little to no back pressure, it will play holy terror on carb tuning and jetting. Add the pods to that and it will be very fun getting it tuned correctly, no matter whose carbs you put on the bike.

[IanDMacDonald]

It Although I am a novice when it comes to the 11, I consider myself an advanced mechanic with the 750/850 Triple, and the GS's, both using Mikuni MKII'S, and BS34's. Why have an adjustable needle clip if not utilized? I tried numerous aftermarket systems and set-ups on my Triples (currently running a Hooker system with K&N pods), with no more than a drop in tge needle clip two positions. However, accounting for your home-made system, who knows besides a Dyno. My suggestion for the elimination of headaches to try and maintain stock as much as possible, and that includes not drilling holes in your airbox, etc. Those Japs knew what they were doing when they built these bikes, and accounted for exactly how the bike was designed when tuning the carbs. So, unless you have access to a Dyno, you'll never really be spot-on tuning the Mikuni's. Plug-chop methods, colour tune, etc. may get u close, but close is not perfect. The other problem that arises is when an owner has no idea of how the bike is really supposed to perform. Tried to tune the bike based on how you think it's supposed to perform versus how it's designed to perform are two different things. If it was my bike, I'd save my pennies, and buy a Mac system or whatever "blessing" u can get your hands on, and tune the carbs based off a system that you know is spec'd for our bike. Just my two cents.

[motoman]

It Although I am a novice when it comes to the 11, I consider myself an advanced mechanic with the 750/850 Triple, and the GS's, both using Mikuni MKII'S, and BS34's. Why have an adjustable needle clip if not utilized? I tried numerous aftermarket systems and set-ups on my Triples (currently running a Hooker system with K&N pods), with no more than a drop in tge needle clip two positions. However, accounting for your home-made system, who knows besides a Dyno. My suggestion for the elimination of headaches to try and maintain stock as much as possible, and that includes not drilling holes in your airbox, etc. Those Japs knew what they were doing when they built these bikes, and accounted for exactly how the bike was designed when tuning the carbs. So, unless you have access to a Dyno, you'll never really be spot-on tuning the Mikuni's. Plug-chop methods, colour tune, etc. may get u close, but close is not perfect. The other problem that arises is when an owner has no idea of how the bike is really supposed to perform. Tried to tune the bike based on how you think it's supposed to perform versus how it's designed to perform are two different things. If it was my bike, I'd save my pennies, and buy a Mac system or whatever "blessing" u can get your hands on, and tune the carbs based off a system that you know is spec'd for our bike. Just my two cents.

A BIG +1!! Being a real quick bike for their weight on the lower end with stock gearing, Would not surprise me at all to the number of XS's here that do NOT run to their full potential stock, from glassy smooth lugged at the bottom end to the quick 6-8500rpm that they do with two quick glances at the tach.......if left stock intake and as close as you can get mimicking stock exhaust since so many of these fell victim to the aftermarket exhaust/intake 'snake oil' craze, the better the bike will run on bottom, mid, and top-end.

[Nightengale]

fj1100 carbs

i am running fj1100/1200 carbs, and they run awsome. there are two drawbacks no vacume advance (but can be drilled out and added) and you need a handlebar choke lever or just do like i do and hold the choke out with my hand till she gets up to temp. they also have the push/pull throttle cable set up but can be run with just the single cable (custom throttle cable). but you can tell a big difference over stock.

[mack]

Funny thing

My SF had the clip setting one position to the rich side when I first took it apart during the restore.(No one had touched them since I originally bought it) When i put it back together I centered them and ran the bike for a summer like that and never could get any color on the plugs no matter what I did with the idle screws. I new it was lean throughout the tach. So the following winter I moved them back to what was factory set position and bingo I have just a slight color now, just the way they should look. I kept track of the milage between the two settings and it worked out to 9 miles difference per tank. The SF is stock exhaust and airbox and interestingly enough, the colourtune adjustments put all the idle mixture screws back to the 1 1/2 turns out setting.

[airborneXS]

well i have pods, and my exhaust is definitely not stock...i made something similar to XS Shops Chops (http://shopschops.blogspot.com/2009/...-jan-2009.html), except with a different style of turn down exhaust tip. I used a short weld in baffle similar to the picture on that page...