Ninja EX500 carbs on an XS650?

[ippytattoo]

I just found a keihin cr special kit for the EX500 that logic dictates will work on the xs. http://www.power-barn.com/servlet/the-737/Kawasaki-EX500-Keihin-CR/Detail

Half the price of the awesome tm34-120's, http://www.mikuni-topham.de/ENGLISH.../XS650_TM34-B120_English/TM34-B120_XS650.html
I can't imagine they would run much worse.

My only questions would be fitting them into intake boots and supplied jets. It just so happened that the cvk's fit perfectly into the BS34 carb holders. The link you posted says they come with new spigots so that tells me that they do not fit in the original ex500 spigots and therefore not in the BS34 carb holders either. Before spending that kind of dough I would definitely be getting ahold of them to verify if they fit in the original ex500 spigots. Also since we are having to change the jets and needles on these a good bit their included jets may not be big enough for our application.

 

[yamahammer]

Cr specials have removable/interchangeable spigots. They have to come with something or they would come with no spigots to choose your own size.

Not that I have the money. I was just bringing an interesting tidbit to light for other builds

 

[pekka]

Mounted my carbs today to JBM holders. The carbs are actually a little wider than the bs34. About 2mm or so. However they fit and seem to be tight. Made up a cable from mix and match parts I had. Throttle is a lot faster than stock. Should be good.

Pekka

 

[troopthrowback]

Mounted my carbs today to JBM holders. Throttle is a lot faster than stock. Should be good.

Pekka

What throttle are you running?

 

[pekka]

What throttle are you running?

I guess it's from some big Yamaha sport bike. I got it from a friend an am not sure where it originally came from. It had dual cables but I only used one. The original cables were about 30cm too short for the XS so it must have been a crotch rocket with clip-ons and really forward motor

The reel of the throttle tube is a bit larger in diameter than the old throttle I was running and I think the lever at the CVK carb is also shorter.

Pekka

 

[scabber]

Setting up another set of carbs for my 650 motor went with the GJH needles on these. I might try them on the 750 and compare them to the JJJ needles.

 

[troopthrowback]

Need help on throttle cable for stock XS throttle to cvk carbs from ex500. What works? I want to use the stock yamaha throttle. Will an ex500 cable (push or pull?) work? What is everyone using?

 

[cbrrudy]

Stock XS650 cable will work fine. You will have to do some slight reforming of the EX500 cable bracket, but pretty easy. A push cable is not needed.

 

[troopthrowback]

I'm guessing you bored it slightly for the cable end? I guess I worry that it eliminates any provision for cable adjustment. I kind of need to replace the existing throttle cable anyway, so searching for a better option that allows for the adjusters at the carb end sounded like a good idea.

I also noticed that the carbs are slightly wider than the JBM holders prefer for perfect fitment. I was thinking I might try adjusting the bracket holes on the carb bridges to allow for a little adjustability. That is, if there's any slop allowed in the o-rings... Any smidge will help. I hate the idea that I just spent $75 on carb holders that don't fit perfectly...

 

[56nomad]

Need help on throttle cable for stock XS throttle to cvk carbs from ex500. What works? I want to use the stock yamaha throttle. Will an ex500 cable (push or pull?) work? What is everyone using?

TTB, I've kept the original XS650 throttle twistgrip and cable and not gone with a push/pull arrangement set-up either. It was easy to do:

Wanting to have an element of cable adjustment I fitted a Yamaha brake cable adjuster like the one in the pic attached http://www.ebay.co.uk/itm/Motorcycle-Brake-Cable-Adjuster-7mm-Cable-End-6mm-Thread-/360852565032?pt=UK_Motorcycle_Parts&hash=item54047d2c28 to the 'pull' cable bracket on the CVK. Screw the adjuster thumbwheel near to the top. Find yourself a M6 nut that fits the thread of the adjuster and cut a slot in it so the cable will pass through it just like the thumbwheel. At the carbs, slide this nut underneath the U-shaped cable holder then slip the adjuster down though the U-shaped cable holder and screw it into the nut. You now have a an adjustable throttle cable holder. Work out how much adjustment this allows you then set it in the mid position.

You're going to shorten the outer cable now. With the cable still attached to the twistgrip, carefully detach the silver ferrule from the carb end of the outer cable and let it hang on the inner for now. Attach the inner cable to the carbs and, with all the slack in the cable taken out, lay the cable alongside your new adjuster/holder. Work out how much of the outer cable needs to be removed so that when this is mod is completed the outer cable will seat down in the adjuster leaving little or no slack when fitted for use. Mark the outer cable then check what you've done again. When you're confident that you're not going to be cutting too much off CAREFULLY remove the excess outer cable with a Dremel cut-off wheel or similar. Slide the silver ferrule back up the inner and reattach it to the outer. You now have a modified XS650 throttle cable.

Set your new cable adjuster to its lowest position and fit the cable to the carbs. Adjust the adjuster to leave just a little slack in the cable at idle then lock it all together with the M6 nut. Job done!

Ian

 

[timbeck]

Nice explanation with pics, thanks 56. tim

 

[troopthrowback]

Wow, fantastic write up and thanks for the help! That explanation is super thorough.

Since my stock cable is kinda junky anyway I'll give this a try and report how it goes when I get back from vacation.

For now, off to Disneyland!

 

[xs650dreamer]

hey guys just thought id let you i think jbm does carry diaphrams for these carbs. if i were you id do some measurement and check it out. just in case haha

 

[pekka]

Test ride today!

Setup:

• Stock bore
• Light porting
• 1 1/2 turns on the mixture screw
• #40 pilot
• #140 main
• HKJ needle 4th (?) slot from top
• gutted Dyna mufflers
• 35mm ID 2-to-2 pipes
• Pipercross foam filters
• 50mm piece of 50mm ID rubber hose acting as "velocity stack"

Increadibly easy to start with these carbs.

Good sounding idle, exhaust pressure feels the same on both mufflers.

Some off-idle or low RPM stumble but when RMP's got higher it was GO! Felt really good!

Was not able to do any high RPM or high speed yet.

Any ideas for the stuble? Rich pilot or needle? I dropped the needles one slot but wont be able to test until I change valve stem seals. Lots of oil leaking into intakes...

Pekka

 

[xs650dreamer]

Are these carbs 34 or 36mm?

 

[troopthrowback]

Are these carbs 34 or 36mm?

34mm cvk keihin.

 

[scabber]

Try the 5th clip.

 

[xs650dreamer]

Can one. Of you guys measure the diamet of the groove where the diaphrams go ? I think jbm has replacemt for these guys but I wanna make sure before I get a set of these carbs

 

[Maurice]

Can one. Of you guys measure the diamet of the groove where the diaphrams go ? I think jbm has replacemt for these guys but I wanna make sure before I get a set of these carbs

Why would you want to do that? These carbs are fairly recent and there are plenty at the breakers or eBay. Much cheaper IMO to get a crappy looking set which will likely have good diaphragms. At least there's no dealing with crazy glue etc. I got a whole set on eBay for cheap and brought it back to life (looked like it has been stored in mud...) just to see if it was worth getting good carbs later. Well, it's not worth it. The old crusted up carbs cleaned up just fine, and it's my daily rider kick only

 

[xs650dreamer]

same reason they sell them in the first place