Ninja EX500 carbs on an XS650?

scabber said:
Nice job on the installation. What is your view on CVK vs BS 34 performance wise. I bet that those kick as 34's stay on the shelf.
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They indeed destroy the 34s. The 34s are not going back on... This things pulls like a beast now.

I'd be curious as to what the comparison looks like on a Dyno...
 
I found the same results. The dyno results will be interesting. You might find gain in HP .They shure do pull hard and don't stop pulling until you let off. I was well over 8000 RPM still pulling from not letting of soon enough. They are amazing. :thumbsup:
 
3dognate said:
They indeed destroy the 34s. The 34s are not going back on... This things pulls like a beast now. .
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As the saying goes, "Once you've had 'Kwak' you'll never go back!" That's right isn't it? :yikes::thumbsup::D As I've said before, I'm well pleased with 'em. In fact I've just grabbed another pair off Fleabay for my '79.

Now that I've got a few miles under my belt with these carbs on my Latte-Racer, my only issue with these carbs is their off/on characteristic while trickling through town traffic at low speed in 2nd gear. That said, the magazine testers of the day found this 'snatching' was a trait of the standard bike too so maybe it's not the carbs at all. Mind you, my pipes and r/c megas together with no torque inserts probably don't lend themselves to smooth town work!!! Increasing the idle speed to 1400rpm does help although that brings on it's own problems. Ride it like you stole it and they're ace.
 
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Low speed chain slap is your bike telling your in the wrong gear most of the time. If have changed sprockets for highway speeds it might be more prevalent. The 650 gearing not the best for stop and go to craw traffic. A bigger low speed jet might help if it is carb related.
 
scabber said:
Low speed chain slap is your bike telling your in the wrong gear most of the time. If have changed sprockets for highway speeds it might be more prevalent. The 650 gearing not the best for stop and go to craw traffic. A bigger low speed jet might help if it is carb related.
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I'm running 17/33 sprockets. I don't think it's chain slap but as I'm not familiar with that I could be wrong. Is it similar to gear train wind-up in a car? It really does feel like a pronounced stumble as I gently open (as opposed to cracking it open) the throttle to speed up a little from a very low speed. I've already gone up from 38 pilots to 40 pilots but as no-one else appears to have needed to go bigger I've not intended to go to 42s.
 
Xs650 has significant driveline lash at low speed. That's a fact. Could be dirty/clogged fuel passages or incorrect float height setting.

That said, I too get a stumble every once in awhile right off idle but only on the street. Never on trails where I run little to zero throttle for long periods of time.
 
If increasing the pilot jet didn't help. It might not be a carb problem. Very low speeds in 2nd gear and the bike tries to stall and bucks a lunges is what I consider chain slap. A mild case might be what you are experiencing if you are not in 1st when this occurs.
 
If you have tip-in issues then you should try changing the needle diameter (last letter in the needle designation) instead of changing the pilot jet.
 
mrriggs said:
If you have tip-in issues then you should try changing the needle diameter (last letter in the needle designation) instead of changing the pilot jet.
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Hello Mr Riggs, The pilots were changed way back as I could not adjust the idle mixture properly as it was too lean at that point. 40s gave me back adjustability. With the mixture ok at that point, with reference to the stumble, I'd been thinking along the lines of finding a needle where the point of transition between the needle base diameter and the taper was further 'up' the needle (towards the grooves) so giving a richer mixture that way. I'd even thought about doing a partial XSJohn's Mikuni needle mod to the JJJ needle. But ....... the enjoyment of simply riding the thing out of town then wacking the throttle open, makin' noise, etc, etc just got in the way! I'll have to knuckle down and get the needle chart out. Thanks for pushing me back in that direction, Mr Riggs. Now before I do I think I'll have a quick blat on the bike. Oh no, it's started all over again. Haha
 
Pyrobooster said:
hello all,

Regarding the throttle cables couldn't these from Mikes be modded relatively easily to work on the EX500 carbs? http://www.mikesxs.net/product/48-9150.html

I have a set of ex500 carbs on the way now. Can't wait to install them.

Regards,
pyro
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The ex carbs are for a single pull cable.

I ordered a cheap stock ex500 cable and a new Stock type xs650 cable and cut it to length and grafted the ex500 carb end of the cable on.
 
XS1961 said:
I modified a stock XS cable for single 'pull' , doing away with the 'push' option.
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Same. Easy-peasy. See my earlier posts.

Hello again XS1961. You'd been away for such a while that I'd thought you'd given up. Have you bought another set and joined the Keihin Carb Collective again?
 
so I've been running the EX500 carbs for a few weeks now. I've only noticed this the last couple of weeks now that the temperature is dropping here. My bike runs fantastic when warm, but is far from an easy start when it's cold. (i might never get it started if I had to kick it....)

Any thoughts... the enricher doesn't seem to help as I pull it out and it won't run with it engaged.
 

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