XSJOHN'S NEEDLE KITS FOR BS34 CARBS 80-84

xsjohn · Last edited by xsjohn on May 28, 2008, 11:06 am; edited 58 times in total

If you guys want some terrifiic needles for your BS34's......PM me......
I finally determined that the factory needles no mater what you do to them will never run right and will eventually destroy your engine....Lots of years work and they are really good......These carbs have a lot more potential that even I realized...

Secondly these engines run 25 degrees hotter on the right side.....these kits help compensate for this allowing the engine to run at it's full potential......right cylinder running hotter occurs on all XS's and not just those with the BS'34 carbs.....the jet needle (main needle) is the single most important part on the entire motorcycle and almost always overlooked.........

Droping overall cylinder temperatures 20 degrees.........and boosting power output considerably........and correcting the right cylinder temperature at the same time.......

You engine will run...quieter...smoother.....cooler.....start easier......develope more horse power and last longer.........and be a bunch more fun to ride......

I think these are the best carbs that Yamaha ever made for the XS except for the needles.......fix this and these are great.........no other modification to the the the carb is necessary........for those who don't want to dismantle their carbs the kit comes with a shim for the 132.5 stock main jets and stock air filters and pipes....and a shim for the 135MJ and larger for advanced modificatons.....

FOR PODS AND PIPES
For much greater improvements replace the 42.5 pilot jets with 45 or in some cases a 46 custom pilot for more extreme mods.......Stock air jet is 135.....personally I like the 135 air jet because mine runs along smoother at cruise with mine..."SMALL CONICAL PODS WILL CAUSE STUMBLING AND OVER RICH CONDITIONS".........

IGNITION
The best ignition is the stock electronic TCI ignition.......the mellow advance curve below 3000 rpm allows for a steady cruise.......Yamaha did it right...I still prefer to retard mine 2 degrees or about 3/32 to 1/8"" to improve the cruise even more......some of the other add on electronic ignitions do not maintain the factory advance curve and go to full advance below 3000 rpn which will give you a jerky chain snatching cruise.....be warned.......

SPARK PLUG CHART www.dansmc.com/Spark_P...talog.html

..SATISFACTION GUARANTEED .....these will save you a lot of tuning hassels and time...instant money back if your not tickled pink.......no questions asked.........

..................................
With straight open exhaust or very free flowing a few of my customers have found the custom 46 pilot I came up with is the best..........not available but I will tell you how it is done......have to have a real micrometer......Chinese one may or may not be accurate...

BS34 deceleration ............popping free flowing exhaust relief............

Local music store......the extra guitar string box......look for 18 plain steel guitar string.....package will lie so you have to measure.......find one that is .018 thousands.......exact is best......this gives you a 46 pilot.........just debur the end of the string and push it through a smaller pilot jet...bit of a challenge but it will go with a little persuasion.....little valve grinding compound or comet to get them both the same.....them set mix screws at 1 turn to start with........

Now offering a 134 Custom main jet ........

xsjohn

John Underwood....email address...........xsneedles @ gmail.com

Some other threads with referance to Johns needles; yamaman

www.650rider.com/index...ns+needles

jimmer · Posted: May 15, 2007, 8:18 pm Post subject: Re: THOUGH I'D RATHER BE IN PARIS

Ahh the pinnicle, the apex ... I am there except for a small ... ahh the hell with me ... wtg xsjohn ... nice. But really ... there must be some miniscule minor technicality that needs attention Smile

xsjohn · Last edited by xsjohn on May 24, 2008, 8:57 am; edited 4 times in total

Oh No....Riding buddy says "touch that thing I'm gonna kick your ass"...He means it......I'll sneak out after dark maybe I can find something....like maybe some covers for the BS34 mixture screw towers......

John

xsjohn

Questions about the kits........

Guess I should answer this ........I make for the BS34’s on the 80-84 XS’s. (and the earlier models as soon as the weather breaks)

First of all I have established that the right cylinder runs hotter than the left. ..Temperature readings by myself and later by other members have pretty much established this to be an inherent characteristic of the XS ….And the farther the machine is driven the worse this situation gets…….causing a heat and running imbalance that also adds vibration and engine noises……

Although this situation occurs on all XS’s the situation is made even worse because of the leanness of the BS34 carbs….

I have been working on Kits that not only correct these mixture problems and make the 80-84’s run much better but my kits also compensate for the hot right cylinder’s imbalance…..a tricky procedure that took me 2 years to learn the correct way….This gives them much more power and makes them run smoother and cooler…..This I have proven in the 51,000 miles I have driven this one including many thousands of miles on the expressway………

Without sounding like a braggart the 80-84’s would be pretty much useless to me without these kits…I built these for myself long before even a thought of offering them….. I think the BS34’s are “mechanically” the best carbs that Yamaha made for the XS ….. 2 complete summers of work on my part…

I also discovered that No stock needle shimming…Changing main jets ….or Aftermarket needles…or any combination of these will not work correctly on the BS34….. after what I have learned I consider this to be a fact …I would still be using the other methods which I also worked on for 8 years prior if they had a chance of working correctly…….absolute correct needles are to me “by far” the single most important parts of the XS’s…and almost always overlooked or misunderstood…..admittedly I had to learn all this the hard way myself……Hope I haven’t offended anyone…..this was not my intention………

John Underwood

xsjohn

If you are looking for another way to adjust your mixture screws you might like this method…..presuming all else is set correctly…….

Having the engine warmed to operating temperature prior to doing this and the plugs wiped clean around the outside ring is needed.....

Take a rag and a small screwdriver and spark plug wrench and go for a for or five mile ride on easy cruise throttle…..stop and pull the plugs and with the end of you finger wipe the outside ring of the plug…check your finger for soot…..no soot at all it is lean…..lots of soot to rich…..just a very very faint sign of soot is good…adjust mixture screws in to lean and out to richen…..and do each cylinder individually…...just a bit of a turn when you are getting close…..each time wipe the end of the plug with the rag and try again………...again do each cylinder individually......when this is done you should see an improvement in smoothness at cruise and maybe some better gas mileage.......in summer weather this can be repeated because of elevated head and cylinder temperatures ........

If you like your mixture screws set richer than stated above...which I think would be to rich except for hot weather and can mess up your cruise.....the same method can be used.....just judge the soot from each cylinder...........and get them the same......

New kits for the 135MJ are done and they kick ass and get 49-50 MPG....6 months of some heavy dicking with.........

QUICKER THROTTLE.........Just make sure you heat it properly or it can break.........

xsjohn

26sam10

John, what is your price for the needle kits?

xsjohn

Need to PM me for that..........thanks

xsjohn

woodman · Full Member Joined: Oct 12, 2008 Posts: 256

John, do you think the breather inlet {outlet ?} being right in front of the opening to the right carb could have anything to do with the temp variation ? The breather tube sticks up about an inch and is 1/2 inch in diameter right at the mouth of the right carb. Do you make needles for the 78 models ? I noticed a snap ring that has to be removed to get the needle out but it takes a longer set of snap ring pliers then I own to reach it. Is that how you get the needle out ?

xsjohn

Hotter right has been found on all XS650's....even with different carbs and air filters.....yes I make 78 needles......can make snap ring pliers from small needle nose pliers....just carefully grind the point...that's what I use.......

xsjohn

weekendrider

xsjohn wrote:

can make snap ring pliers from small needle nose pliers....just carefully grind the point...

ditto $2 pliers with 4" jaws ground down

Blackbird · Posted: May 15, 2009, 8:00 am Post subject: Re: NEEDLE KITS FOR BS34 CARBS 80-84

xsjohn wrote:

If you guys want some terrifiic needles for your BS34's......PM me......
I finally determined that the factory needles no mater what you do to them will never run right and will eventually destroy your engine....Lots of years work and they are really good......These carbs have a lot more potential that even I realized...

Secondly these engines run 25 degrees hotter on the right side.....these kits help compensate for this allowing the engine to run at it's full potential......right cylinder running hotter occurs on all XS's and not just those with the BS'34 carbs.....the jet needle (main needle) is the single most important part on the entire motorcycle and almost always overlooked.........

Droping overall cylinder temperatures 20 degrees.........and boosting power output considerably........and correcting the right cylinder temperature at the same time.......

You engine will run...quieter...smoother.....cooler.....start easier......develope more horse power and last longer.........and be a bunch more fun to ride......

XSjohn ...The needles look similar. What makes them different? Size?

jayel

Blackbird wrote:

The needles look similar. What makes them different? Size?

it's a secret he could tell you, but then he'd have to kill you

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