Author Topic: My 1975 XS500b before and now  (Read 12272 times)

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Offline dreadrock

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Re: My 1975 XS500b before and now
« Reply #15 on: August 04, 2013, 02:01:40 AM »
  Well I haven't enjoyed the newtronic ignition at all . Has been a problem from the start really so pulled it out of the bike and put points and condensers installed. Bike is running great now have a few things I want and need to do then back out on the road I go .
 Seems to want to bog up top so think its a main jet thing will see !

Offline 2winged

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Re: My 1975 XS500b before and now
« Reply #16 on: August 04, 2013, 07:06:11 AM »
Your bike definitely deserves the recognition over there. Damn nice bike!

Offline dreadrock

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Re: My 1975 XS500b before and now
« Reply #17 on: August 05, 2013, 03:43:06 AM »
Your bike definitely deserves the recognition over there. Damn nice bike!

 Thank you sir  ;D
 
 Heres a few more ...




Offline Nurali

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Re: My 1975 XS500b before and now
« Reply #18 on: August 05, 2013, 12:09:58 PM »
Man, what a lovely build!
Im thinking of upgrading brakes too.
Did you have to do custom fitting? how easy was it to upgrade them? :)
And I can see you replaced the old brake master cylinder thats placed on the lever, what did you use there? :)
Cheers
Nurali

Offline dreadrock

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Re: My 1975 XS500b before and now
« Reply #19 on: August 06, 2013, 01:45:10 AM »
  Thanks !

A FZR 600 disk fits right up same hole Pattern just need 1/4 inch spacer to move disk away from wheel , pulled studs out and used hardens Allen head bolts . Running SV650 caliper trimmed off the back some to also give more room from the wheel . Then made new bracket to center the caliper and bobs your uncle ! Front M/C is a GSXR master both are 10mm and think 1.25 pitch . Back brake Is also a FZR and need a bigger spacer made was a bit of work . Also used a FZR caliper to make it easier ( LOL ) to get things to fit , pulled studs and bolts same as front . Rear M/C is off a R6  !!!!! Way to much brake for the bike but it works and works well  ;D
Brake lines are Spigler lines and after ask a few guys that's done it called and ordered length and angle of banjos and which thread pitch I needed ! Again was work but worth it !

Offline Nurali

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Re: My 1975 XS500b before and now
« Reply #20 on: August 06, 2013, 09:01:14 AM »
simply amazing, great work mate!
what about those carb, whats your experience with them? I imagine great performance difference compare to stock ones..
Is it mikuni VM?
I thought of upgrading to a pair of VM's, but unsure of size.
They go from 30 to 36, what do you think would be the best choice, if there's such thing of course..  :)
« Last Edit: August 06, 2013, 09:09:12 AM by Nurali »

Offline dreadrock

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Re: My 1975 XS500b before and now
« Reply #21 on: August 06, 2013, 03:55:22 PM »
 There VM32s and work great ! Have them on stock carb boots just need a good hose clamp to get them to seal !  Think anything bigger would be a lot of tuning and these where close right out of the box with stock motor . Only thing is im running K&N filter and seem to let to much air thru so used wrist bands to help and help they did !

Offline Nurali

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Re: My 1975 XS500b before and now
« Reply #22 on: August 06, 2013, 07:26:46 PM »
There VM32s and work great ! Have them on stock carb boots just need a good hose clamp to get them to seal !  Think anything bigger would be a lot of tuning and these where close right out of the box with stock motor . Only thing is im running K&N filter and seem to let to much air thru so used wrist bands to help and help they did !

Considering that the stock carbs work fine at the moment on my bike, would you still consider upping them with 32's?
I mean there's a noticeable performance difference there right? :)


Offline guylr

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Re: My 1975 XS500b before and now
« Reply #23 on: August 06, 2013, 08:02:37 PM »
On a 35 year old bike if the stock carbs "work fine", I probably wouldn't mess with it. At most you might expect a little better throttle response and maybe a horsepower or two on top. But you might get worse response and a horsepower or two less and that would be after many hours of jet swaps and test runs. That can be fun but you have to ask yourself what is more fun? Riding the bike or working on it?

Guy
Now Retired Yamaha guy. Cut me and I bleed "Cinquasia Red"

Offline dean

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Re: My 1975 XS500b before and now
« Reply #24 on: August 07, 2013, 01:16:00 AM »
.......... Only thing is im running K&N filter and seem to let to much air thru so used wrist bands to help and help they did !

As an old fart who loves to tinker with carbs, I have to offer this: The K&N's are not letting too much air through...   The problem is you need to go up in jet size and tune correctly for good carbs and filters . Wrapping filters with wrist bands to reduce air flow in order to correct for a lean condition is a band aid.  just sayin  ;)

Offline dreadrock

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Re: My 1975 XS500b before and now
« Reply #25 on: August 07, 2013, 03:50:26 AM »
.......... Only thing is im running K&N filter and seem to let to much air thru so used wrist bands to help and help they did !

As an old fart who loves to tinker with carbs, I have to offer this: The K&N's are not letting too much air through...   The problem is you need to go up in jet size and tune correctly for good carbs and filters . Wrapping filters with wrist bands to reduce air flow in order to correct for a lean condition is a band aid.  just sayin  ;)

I went with the 32s because the stock ones where shot and wanted a cleaner look but if the stockers work keep with them !
Dean thanks for the info I would like to run with out them I'm ta noob with carbs and trying to figure them out  ;) if one ever dose !
 Running : main: 120
                Clip : 4 th down from top
                Pilot  : 30
               Air screw 1/2 out
Any thoughts would be appreciated sir !

Offline dean

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Re: My 1975 XS500b before and now
« Reply #26 on: August 07, 2013, 04:34:44 PM »
I can not tune your carbs from here, however I do have a large cup of coffee and some time to type ( one finger typing  :-\  however )

There are some steps that need to be completed thoroughly and in order. There are no short cuts to carb tuning ( yes, you can get a bike "running decent"  without proper tuning, however if a bike is way lean, you are in danger of  over heating that could damage your head or seize the engine. If way rich,  the bike  could end up with 15 hp and 15mpg !  )

I see allot of guys tossing jet sizes and carb setting back in forth over the internet. This is not carb tuning. (Having your air screw out only 1/2 turn is a clue that your pilot jet is too small though and you are lean with 120 mains as you found a need to restrict the airflow with the wrist bands)

Yes, if you have a box stock bike, there is a list of jets and settings for that in the manual, however you bike is not stock:

You  have a 1975 bike running on 2013 fuel ( with 10-15% ethanol by the way )
You have shortened head pipes and shorty mufflers with less restrictive baffles.
You replaced the CV carbs with "generically jetted" Mikuni VM carbs with K&N filters

That being said, you can become an expert at tuning your bike with your specific and unique set up. There are no short cuts or magic list of jets that someone can post for you that can optimize your tune.

Step one- read the Mikuni super tuning manual. It has good info on your VM carbs , you will learn VM carb theory , and  gain a better understanding of your carbs and general tuning. Download it here:
https://files.secureserver.net/3sSZzj2YGzA08H

Step two- google "plug chops" and also download  this guide chart on how to read plugs: 

http://i820.photobucket.com/albums/zz121/deanjarrett1/cafe%20bikes/SparkPlugReading_zpsb0ed9c8d.jpg

Most of us do not own,  or have access to a dyno .... nor have O2 sensor bungs welded into our head pipes with a wideband A/F meter next to our tach. Plug chops are the best way to check / confirm we have a good air fuel mixture and the various throttle settings ...

Step three- buy several sets of brand new plugs to perform your plug chops

Step four- confirm with yourself that your ignition settings and timing are spot on and your plugs are new and correctly gapped.

Step five- make sure you have no vacuum leaks whatsoever around the intake boots and that your slides are perfectly synced. Also, the 80's called and want their wristbands back, so remove those please  ;D ( properly tuning carbs do not involve any added restrictors , lollipops etc  )

Step six-  download Peter's simple one pager on jet tuning, it will show when to perform plug chops and recommends which way to go on jets:

 http://i820.photobucket.com/albums/zz121/deanjarrett1/cafe%20bikes/PetersJettingAid_zps40087e40.jpg

Be very patient, go step by step, take zero short cuts, and invest in the time, the jets, the plugs etc to do it right and you will thank yourself  :)

Offline dreadrock

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Re: My 1975 XS500b before and now
« Reply #27 on: August 07, 2013, 05:48:37 PM »
Dean I do understand when you say " no short cuts " and I can't thank you enough for the info you have given me ! I will be picking up more jets this weekend and send the wristbands back where they belong ! Again sir thanks alot for the info will put it to good use !!
Scott

Offline Nurali

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Re: My 1975 XS500b before and now
« Reply #28 on: August 08, 2013, 01:59:42 PM »
Im glad I could contribute with my carb questions :)
Ill let you know if I decide to do it, maybe it will be a winter project-who knows :)

Offline lowdirt

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Re: My 1975 XS500b before and now
« Reply #29 on: August 13, 2013, 04:17:04 PM »
I really like your seat, fab it yourself? planning on doing something similar for my xs500 via the foam mold/fiberglass and resin method.