Ninja EX500 carbs on an XS650?

Maurice said:
Yes they fit fine.
Click to expand...

Good to know. Back to carbs I was thinking about the 138 main jet. When I was bench racing these carbs I was considering the 135 main Sudco was out of stock. Since mrriggs was finding success leaning out the needles a smaller main jet might work better or not. Guessing at this point with the BS 34 the 135 main worked well stock needles. I should have the Uni filters this Friday. More testing and tuning. :thumbsup:
 
Put on the Uni filters out for ride. The bike kicks ass no need to tune just enjoy the ride. I would call them a performance carb over the bs carbs put on the 650. :thumbsup:
 
Hit a bit of a milestone today, not necessarily carb related but still; got rid of the starter solenoid/wiring/safety relay (have to remember to turn the light on now) and for the past week it has been kick only. Cold starts have always been an issue, especially with the changing weather/humidity etc. It seems I would always "miss" the opportunity and use the wrong choke opening at first kick, I'd end up having to kick 5 or 6 times with no choke. It always ends up starting but I knew I could do better.

This morning I tried 1 kick half-choke no ignition, then turn on ignition and get on it: bam! No, no kickback, fire right up. We'll see if I have this down for next time :D Great way to start the day (e-start makes/made me cringe...) Excited about removing the big battery, starter motor etc.

At any rate, re: carbs, I think that seat of the pants tuning is done for me, the bike runs really well at all ranges with 38/138 jjj middle and pods. It'll redline easily and pull real well from 2k up. Red light/stop take offs are really smooth and confident, and going around turns throttle is real steady as well. Seems like the tinkering is done for me.
 
Still making progress with the jetting. I dropped the needles down one clip position and picked up a lean surge while cruising. That's the first ill effect I've experienced. On the plus side, when I give it gas it pulls harder than it ever has. That lends me to believe the taper is still too steep. With a leaner taper I will be able to raise the needle back up to improve the cruise mixture without losing the improved acceleration above half throttle.

A G would be the next leanest taper but they don't make a GJJ needle. They do have a GJH and a GJK. JetsRus doesn't list the GJK so I went with the GJH. It hasn't showed up yet but I'm feeling pretty confident that I'm on the right track.

My gas mileage has been a consistent 54 mpg. Lowering the needle had no effect on the mileage.
 
Thanks for the update mrriggs. I'm having great success with the jjj needle clip in the middle. My bike vibrates less with these carbs. Wondering if you are experiencing less vibes also.
 
Thanks for you all for doing the research on these carbs!

I'm working on a pair of CVK's for my bike but I'm having trouble finding parts. Are there other sources for jets and needles than Jetsrus? One that takes PayPal would be great. Specially the needles are pain to find on this side of the Atlantic...

Thanks,

Pekka
 
jetsrus does take paypal. Maybe they don't ship international?

If you need anything let me know, I can order here then forward that to you. What country you in?
 
Another nice feature of the CVK the bike runs perfectly with the bike on its side. No racing engine or leaking gas. :D No damage to me and the bike. The left leg doesn't work all that well badly broken crushed foot. Couldn't get my foot off the peg in time after stopping. Had to lay it down gently to far over to hold. After rereading mrriggs post on the JJJ needles I might go 4 slot on the needle inquiring mind needs to know better or worse also using the 34 plastic donut. I haven't checked the vacuum sync. Sync screw is paint marked from factory and I did not change it. Will report back.
 
scabber said:
Another nice feature of the CVK the bike runs perfectly with the bike on its side. No racing engine or leaking gas. :D
Click to expand...

Unfortunately, I have tested that feature myself. :doh: Just days after putting the CVKs on the bike I had a minor low side. It purred away happily while I got up and dusted myself off.

I put in the GJH needles last week. Started with clip in the #3 slot and it was too lean. I'm on #4 now and it feels like it's just on the verge of being too lean. A shim on each needle would probably be just right. I want to run through a tank of gas on the #4 before changing anything to see how it affects mileage.

I am very happy with the feel of the GJH needles. Acceleration is smooth and linear throughout the rpm range.
 
I'm getting back into this with a passion now! I've put a 'mrriggs' 38/138/JJJ tune on my ex-GPZ500 carbs with the exception of having two brass collars machined up for the needles instead of using the aluminium ones off the original needles. They are 6mm dia, 1.6 thick with a 2.6mm hole as per the CVK/PWK hybrid. Afterwards, by accident, while 'surfing' I came across a CVK34 that is fitted to a 1997-2007 Kawasaki KLX300 (and other KLX and KLR variants) which has an adjustable N1-TC needle with seperate clip and collar. The collars, OEM#92143-1667, appear to be the same as those I've had machined up so I'd suggest ordering a pair at the same time you order your PWK needles. I hope that helps someone.

Now I've a question or two for you guys:

Maurice said:
I'm making a bracket to hold a generic choke pull knob. This thing seems like a keeper to me.
Click to expand...

Maurice, you've a good looking bike there. Your generic choke pull. Which one did you use and was it a straight-forward fit at the 'carb end'?

Did you mod the original XS650 throttle cable or go for a hybrid? If XS, how did you mod it?

Anyone: Have all those who've fitted these carbs had to mod the L-section bracket that joins the carbs together because of interference with the frame downtube? It's looking like I'll have to. I'm still using the original carb holders. Could they be slightly longer than aftermarket ones?

TIA
 
When I first put them on, the frame was in stock form and I did have to clearance it a little bit. After I put on the Ardtail that clearnce issue was no longer there. As far as controls go I am in the process of changing over to OEM EX500 control as I was tired of dealing with cheap chinese knock offs of the H1 controls. I am converting the harness as well.
 
Well, I went and ordered up a set of these carbs from an '05, a set of cables and a right side switch and throttle.
This way I can fit the carbs with the proper cables and throttle.
I have a left side switch housing from an 82 XS with the enrichener lever.
So that can be hooked up easily.
I'll order the jets and needles in the next day or two.
Leo
 
XSLeo said:
Well, I went and ordered up a set of these carbs from an '05, a set of cables and a right side switch and throttle.
This way I can fit the carbs with the proper cables and throttle.
I have a left side switch housing from an 82 XS with the enrichener lever.
So that can be hooked up easily.
I'll order the jets and needles in the next day or two.
Leo
Click to expand...

The stock EX500 cables will be short but motion pro can make cables (or at least I think they can), I am waiting on a reply from them as to cost and definite answer on if they can make the correct length cables. I have 3" risers and 28" wide drag bars and they are about 3" short on the throttle cables and about 5" short on the choke cable if using EX500 controls on both sides.
 
I'm trying to locate jets and needles. On Jets R Us under which Keihin carbs would the jets be.
The needles are from a PWK 28 mm right?
Leo
 

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