Needles

wally · Posted: November 26, 2007, 6:04 am Post subject: Needles

Hey All

[b]Best Thing Since Sliced Bread

I have replaced my needles in my 82 XS with a set of needles from XS John

Best thing I ever did for my baby runs great runs cooler
the best after sales service from John as well

But better yet is still how well my baby performs, now she has a new lease of life & a longer life as well due to the cooling effect of the needles on head temps.

So what all this means is that Johns needles are very much worth A very good look by everyone with a 650

At least give them a go what can you loose by giving them a go.

Just check out my plugs

kazack · Posted: January 3, 2008, 2:56 am Post subject: Re: Needles

pardon my blatant ignorance but what are the needles that you are talking about? I am also interested in prolonging my bikes longevity.

thank you

xsjohn · Posted: January 3, 2008, 11:04 am Post subject: Re: Needles

Guess I should answer this question since he is talking about the kits 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 because there is a hot spot on right intake. ..Temperature readings by myself and later by other members have pretty much established this to be an inherent characteristic of the XS head….the right intake seems to be about 50 degrees hotter than the left when the engine is at operating temperatures…..This is a lot and causes the right to run hotter and leaner because the gasses are more preheated from the head on the right cylinder reducing the cooling effect from the incoming and expanded gasses....And the farther the machine is driven the worse this situation gets…This reduces the power and longevity of the engine …..and causes the right to run leaner and hotter than the left ….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 and 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………

I also discovered that No stock needle shimming…Changing main jets ….standard aftermarket needles …or any combination of these is not the correct way to tune the BS34….. …

John Underwood

pork1450 · New Member Joined: Dec 07, 2007 Posts: 5

Wally I couldn't agree with you more about John's needles. I also have a set and my bike has never run better. Even over here in OZ. and John, another big thanks to you for making these things! ps: hey Wally, where abouts in oz are you?

xsjohn · Posted: January 5, 2008, 4:00 am Post subject: Re: Needles

pork1450......Thanks for the Kind word…….I think the BS34’s were mechanically the best carbs Yamaha made for the XS’ …and have some real good potential if set up correctly…..Here are some examples below that I have run across……

BS38 slides are 2.91 ounces each
BS34 slides are 1.82 ounces each

Lighter slides equals quicker throttle response……..

BS34 has better viton tipped float needle and almost refuses to leak……

The pull choke arrangement is more precise ……….

The BS34’s are 2 LBS lighter than the BS38’s…..the BS34 seem to deliver more usable tork ......But the bs38' are easier to change MJ's........and may have better hight rev potential.......

xsjohn

mlcarter815 · Full Member Joined: Jul 03, 2007 Posts: 64

Are your needles designed for the stock air boxes, or would an aftermarket pod style filter work better?

xsjohn · Posted: January 6, 2008, 11:07 am Post subject: Re: Needles

These have been used with pods or stock filters andeven pods and pipes with great results......I reccomend the stock main jet but one could always use a 135 for extreme modifications........have sent quite a few to people with pods and pipes and they still seem to like the stock 132.5.mj..........

I use the stock air box with a free flowing air filter in it and stock pipes so 135NJ is a bit rich for mine.....and my right cylinder is under control finally....without controling the right cylinder heating these things are pretty much of a hassel for general purpose....I'm getting 50mpg so richer for me is not necessary.......I did find out the hard way that by controling the right cylinder these will run a lot better and farther........I am still on my stock pistons with 150 lbs on both sides......51,000 miles...pulls down the express like a car even with the 18/29 gearing.......or whould I say especially with.......

John

wally · Posted: January 14, 2008, 3:53 am Post subject: Re: Needles

Wallys in Sydney

wally · Posted: January 14, 2008, 3:55 am Post subject: Re: Needles

Wallys in Sydney

xsjohn · Posted: January 14, 2008, 5:38 pm Post subject: Re: Needles

Wally.....You lucky dog.......too dang cold to do anything here...serious cabin fever.....we have even resorted to talking politics......something that always gets me upset........must be nice there.......

John

wally · Posted: January 14, 2008, 7:55 pm Post subject: Re: Needles

Yep Oz is not a bad spot to bunk down in

Not as cold as most places
Dont know how you all (Yanks & Poms) survive your cold weather

5twins · Full Member Joined: Aug 05, 2006 Posts: 1616

What's a pom?

wally · Posted: January 15, 2008, 3:11 am Post subject: Re: Needles

Poms or pommies

People from England

5twins · Full Member Joined: Aug 05, 2006 Posts: 1616

Well then shouldn't it be P-F-E s? I guess we Yanks need a bit of a history lesson here Very Happy

.

jayel · Posted: January 15, 2008, 10:03 am Post subject: Re: Needles

"Yep Oz is not a bad spot to bunk down in

Not as cold as most places
Don't know how you all (Yanks & Poms) survive your cold weather"

well Wally as you know we threw them out in the late 1700's, (1776- 1783) got tired of King Georges BS I guess, but then they establish Australia as a penal colony in 1785, the worst they can come up with to do to you guys is sunshine and warm weather? WTF (written with tongue firmly in cheek)

xsjohn · Posted: January 15, 2008, 10:08 am Post subject: Re: Needles

We have our "penal" colonies here......some in frisco... some in key west...and others places too I'm afraid.........can't forget fire island....

John

wally · Posted: January 15, 2008, 8:03 pm Post subject: Re: Needles

Nothing more we like to do is have a good s*** stir

wally · Posted: January 15, 2008, 8:08 pm Post subject: Re: Needles

The end results of a very hot right side piston

jays100 · New Member Joined: Oct 11, 2007 Posts: 6

Ouchie!

XSAndy · Posted: April 20, 2008, 2:51 am Post subject: Re: Needles

XS John. What difference does it make with the jets if you have iridium plugs in place? They have better ignitabilty for leaner mixtures and perform better as a result. Would the jet change just magnify improvements?

XSAndy · Posted: April 20, 2008, 2:51 am Post subject: Re: Needles

XS John. What difference does it make with the jets if you have iridium plugs in place? They have better ignitabilty for leaner mixtures and perform better as a result. Would the jet change just magnify improvements?

madj74 · 650Rider Supporter Joined: Apr 10, 2008 Posts: 18

Does the 78 xs have the same problem?

xsjohn · Posted: April 20, 2008, 8:41 am Post subject: Re: Needles

All of them run hotter on the right side....no matter if its pods and pipes or any configuration......Been working on this for over 2 years ....it doesn't mean that all of them will fail but loosing the 25 or so degreese on the right I found is a good thing....the right gets leaner than the left at operating temperatures and drives the entire engine temperature up....don't think that is a real good situation in the summer...been working on what I think is the best solution for this......if anyone knew how much time I have spent on this issuue they would slap me..........

Andy.....don't think that a better spark plug will relieve a lean situation...

xsjohn

royfisk · Posted: April 20, 2008, 9:01 am Post subject: Re: Needles

spark plugs will not help with this issue period. It is a jetting issue. and that blown cylinder above is not from stock jetting error either it was do to a far leanner then stock issue. plugged carb more then likely, or one that was lean to begin with and someone openned everything up more except the jets.

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