Ninja EX500 carbs on an XS650?

[Popshot]

Pretty much every secondhand set will need a complete overhaul. Using a sonic bath on mine took out loads of crap on what were a very decent looking secondhand set and the float seats were scrap with new ones right next to rocking horse droppings on the shelf. Others may get luckier than me but I wouldn't take that bet.

 

[Its been a long time]

Yes, you are right about buying more than twenty year old second hand carburettors, without a doubt. Also the sellers now appear to be aware of XS650 owners buying them. The prices being asked are now unrealistic in my eyes.

So yes, what you have is a very realistic option providing they work correctly.

 

[5twins]

I started looking into these CVK carbs recently because I just acquired a Kawasaki W650 and it has very similar CVK carbs fitted. But, they're a bit more complex than these 500 carbs, with more electronic "fittings". So I thought maybe a simpler 500 set might be able to be swapped on. Also, the W650 carbs are jetted much leaner it seems, with only 118 mains, and they use two different needles, one slightly longer (leaner) than the other. Not sure what's up with that, lol. But, I planned on my typical mods (pods and pipes) so I know some re-jetting will be needed. I'm hoping it will just be minor, like our stock 650 carbs. But it's possible the W650 carbs "mirror" the '76-'77 XS650 BS38's. That particular carb set also had very small stock mains (#122.5) and requires more that just one or two sizes larger on the mains, more like 4 to 5.

I went on eBay and the 500 carb sets are quite expensive ($250-$300), so I don't think I'll be getting any soon, lol.

 

[Its been a long time]

I started looking into these CVK carbs recently because I just acquired a Kawasaki W650 and it has very similar CVK carbs fitted. But, they're a bit more complex than these 500 carbs, with more electronic "fittings". So I thought maybe a simpler 500 set might be able to be swapped on. Also, the W650 carbs are jetted much leaner it seems, with only 118 mains, and they use two different needles, one slightly longer (leaner) than the other. Not sure what's up with that, lol. But, I planned on my typical mods (pods and pipes) so I know some re-jetting will be needed. I'm hoping it will just be minor, like our stock 650 carbs. But it's possible the W650 carbs "mirror" the '76-'77 XS650 BS38's. That particular carb set also had very small stock mains (#122.5) and requires more that just one or two sizes larger on the mains, more like 4 to 5.

I went on eBay and the 500 carb sets are quite expensive ($250-$300), so I don't think I'll be getting any soon, lol.

Yes, sellers of used CVK34 carburettors have got very wise that other motorcycles are getting fitted with them. I have also seen the prices increase here in the UK too. To stupid levels.

For those prices it's almost the same as fitting a pair of VM34s. From memory they're often less than $140 each over there, new. I imagine there's W650s out there fitted with VM34.

 

[Wagner73]

My particular bike seems geared for a top speed around 0.5 C as near as I can figure so it's never going to pull arms from sockets when requested to do so. Setting off requires a most un-bike like slipping of the clutch.

Curious as to what sprockets you are running? My 78E has stock gearing (17-34) and 1st doesn't require a lot of clutch slipping (at least IMO), but neither does the gearing "feel" low-low either.

 

[Popshot]

Will have a look but will take a few days due to work.

 

[Wagner73]

I started looking into these CVK carbs recently because I just acquired a Kawasaki W650 and it has very similar CVK carbs fitted. But, they're a bit more complex than these 500 carbs, with more electronic "fittings".

Yes, I think these CVK's can have a number of electrical add-ons i.e. TPS, electric choke, and heat. Have a friend with a Triumph Bonneville America with CVK's and it has heat.

 

[Its been a long time]

Yes, I think these CVK's can have a number of electrical add-ons i.e. TPS, electric choke, and heat. Have a friend with a Triumph Bonneville America with CVK's and it has heat.

Indeed. Bonneville CVK36 has float bowl heating by electric heaters. And TPS unit.

Kawasaki CVK34 has engine cooling water carb heating. For XS650 the water tubes are removed.

 

[Popshot]

Got the new float valve seats. The extra length should be ok but will need to check further once on with the job. They are 0.25mm bigger in diameter which means I need to run a 10mm drill down the bore before setting them with thread locker. I should be able to have a good look into it on Friday.

These are for pwk 33 to 41 carbs.

https://a.aliexpress.com/_EJ1FuKS