Ninja EX500 carbs on an XS650?

[Its been a long time]

Thanks @Signal . I will certainly think about those air filter adapter rings.

Maybe I missed it in the thread, but what did you use for throttle cable and choke actuator? I am going to look at seeing if modifying an XS650 throttle cable works. I can get one 100mm longer than the one that's fitted and that should give me enough flexibility at the carburettor end to make it work?

For the choke, I had a Bonneville T100 that uses these carbs in 36mm. It had a nice left side pull similar to yours but I don't think it would swap over to the Kawasaki carbs.

Thanks for the support, appreciated.

PS - I tried to buy the Ali Express JJJ needles but I don't seem to be able to get Ali Express to work which is a shame.

 

[Signal]

For the choke I used a pattern choke cable and shortened it, then made a bracket to hold the pull knob. Someone in this thread made a lovely brass rotary choke with detents different settings. The link is to the sort I used. For a long time before I fitted the cable I just pushed the choke on with my finger from the right hand side.
https://www.ebay.com/itm/2860162784...SSsMsc46TsQbU3bxMjBwUMoH4=|tkp:Bk9SR97v8ffGZA

For some reason I bought a push pull, quick throttle for a honda CRF 250 and shortened the cables for my road bike. I think I was confusing the need for push pull with flat slides.
I have now gone to a single pull cable with the CRF quick pull for the road bike and single cable Domino quick pull throttle for my tracker.

In this thread members are using the stock throttle and cable but at 54 pages there is a lot to wade through to find the posts.

 

[Its been a long time]

Reflecting on the comments above. I have read on ER5 forums that these carbs run much better with air boxes. I'm tempted to make transition pieces between the ER5 carburettors and the XS650 airboxes. I can't measure up until I get the BS34 inlet rubbers I have ordered. But it certainly seems doable. Any thoughts here about that? Thanks.

 

[Signal]

I think it may help, worth a try. Nothing lost if it doesn't work.

 

[Its been a long time]

Mock up of carburettors and original air box. There isn't any space for a transition piece to fit between the carburettors and the air box. I thought there might be, but no. The carb inlet is 55mm and has a fairly narrow land of only 8mm. The airbox with the rubber seal removed is ~57mm. If I can find a piece of hose 55mm inside diameter, a piece about 30mm long would fit nicely and leave maybe a 2mm gap between the edge of the carb and the edge of the air box. Not bad? (Yes, I know the inlet rubber screws need shortening by maybe 6mm ).

Downside that's immediately obvious is that the centre carburettor pull cable route appears to run right through the cylinder head breather. I don't know how to fix that just yet. Good news is that the nipple on the XS650 throttle cable fits the carburettor but is about 25mm short on free length. And I have no idea how to secure that end of the cable to the carburettor. Given I just found the issue with cable routing and the breather, that's going to take some thinking about.

Also need to trim maybe 3mm off the edge of the cross brace at the back of the carbs. It's scraping the paint on the frame. Picture of the mock up -

 

[arcticXS]

Damn, that is very close! In your picture, it looks like the air box and carb is not aligned on the center line. Is that actually the case?
If you have a second set of air boxes, or are willing to modify the ones you have, I am sure it can b done. For example by clamping velocity stacks/ trumpet to the carbs, cutting the trumpet off the stock air box, and using some kind of foam or rubber seal between air box and velocity stacks.

 

[timbeck]

I have a complete set for sale in the classifieds if any interest. throttle , cable, carbs, rubber manifolds,correct jets, UNI filters....rebuilt by "Ducati Man" .Plug and play Too old to ride and play with bikes

tim

 

[Signal]

So far as the throttle cable end I used an end like the one in the photo with half nuts on both sides. It was swaged to an old cable but I was able to cut it off and reface the end.
The push cable holder was cut off the cable holder bracket on the carb leaving only the pull cable holder.
I have single breather hose set ups and the throttle cable fits past ok on both bikes.
In the photo you can see the single clear reinforced breather hose. It looks like the choke is hitting the dome nut but it clear.

 

[Its been a long time]

Damn, that is very close! In your picture, it looks like the air box and carb is not aligned on the center line. Is that actually the case?
If you have a second set of air boxes, or are willing to modify the ones you have, I am sure it can b done. For example by clamping velocity stacks/ trumpet to the carbs, cutting the trumpet off the stock air box, and using some kind of foam or rubber seal between air box and velocity stacks.

Thanks for the comments. The airbox was only hanging there, when I took my hand off it to take the picture it moved a bit. So the alignment is actually pretty good. Once I sort out the throttle and choke cables and have the carburettors installed correctly, I'll return to the airboxes and look again. I think if I can get a correctly sized piece of rubber tube, it might work. Piece of rubber tube needs to fit 55 and ~57mm diameters. It's going to be close.

 

[Its been a long time]

Thanks @Signal . Could you please tell me the thread diameter of that adjuster? Mocking it up here using screws instead of an adjuster to see what fits best, I found 6mm too small and 8mm diameter looks too big for fitting into the Kawasaki bracket. Obviously, yours fits perfectly, I think I need to replicate that.

 

[Its been a long time]

Found this picture of a Kawasaki throttle cable for ER5. Confirms the use of a threaded adjuster as mentioned above. But frustratingly, I can't find the size of it anywhere.

 

[arcticXS]

Thanks for the comments. The airbox was only hanging there, when I took my hand off it to take the picture it moved a bit. So the alignment is actually pretty good. Once I sort out the throttle and choke cables and have the carburettors installed correctly, I'll return to the airboxes and look again. I think if I can get a correctly sized piece of rubber tube, it might work. Piece of rubber tube needs to fit 55 and ~57mm diameters. It's going to be close.

Maybe a short aluminium adapter, with an internal o-ring on the air box end could work, if there is enough "wiggle room" to fit one?
Or maybe something different, like those split pipe connectors with a rubber sheet wrapped around the pipe ends, and held in place by a split outer housing often in stainless sheetmetal. Just imagine a piece of inner tube, surrounded by a wide hose clamp.

 

[Its been a long time]

Maybe a short aluminium adapter, with an internal o-ring on the air box end could work, if there is enough "wiggle room" to fit one?
Or maybe something different, like those split pipe connectors with a rubber sheet wrapped around the pipe ends, and held in place by a split outer housing often in stainless sheetmetal. Just imagine a piece of inner tube, surrounded by a wide hose clamp.

My intent was to make an alloy transition piece but there isn't enough room in there unfortunately. Some kind of rubber fitting on the OD of both parts is going to be the way forward. I like the idea of some flexibility and vibration isolation that a piece of rubber provides too.

 

[arcticXS]

Here is a pic of those Straub connectors, just for inspiration

 

[Its been a long time]

Here is a pic of those Straub connectors, just for inspiration

Thanks. Never heard of Straub until now

What a shame, none of them will do this job

 

[Its been a long time]

Ordered these yesterday afternoon and arrived 10.30 this morning. Not bad. Everything I need now to mount the carburettors apart from the carburettor mounted cable adjuster. Keyster and Tourmax brassware. Never yet been let down by the quality of either of those brand names. They're always Japanese made and I tend to trust that. Kawasaki spare parts prices seem ridiculous even by modern day standards.

 

[Its been a long time]

New brass etc in the carburettors. 138 main jet, stock needle shimmed 0.5mm higher, 35* pilot jet, mixture screws two turns out and float heights set to 17mm. Noticed that the float bowl drain screws aren't handed. That makes access to one of them a bit tricky when mounted on the bike. The choke cable fits a treat but is too long, have to work something out. Just need to work out the carburettor cable adjuster then I can adjust a spare XS650 throttle cable to fit. Been looking at the adjusters on Venhill's website and nothing really jumps out at me as being obviously correct. * That was in the carbs when I got them.

As I'm intending to use the XS650 air boxes and the difference in size between a 35 and a 38 pilot jet seems to be 0.0012" then I'll try the #35 pilot first. Any case, a twenty year old 35 pilot jet probably isn't still factory size anyway.

Latest news, Venhill say "The adjuster you are referring to, is not available to order via our website. This would need to be order by giving the sales office a call and taking the order over the telephone. The part number for the adjuster is part number:"

A6100C/25

Which requires the following Lock Nut if needed:

LN6100.

The cosmetics of the carburettors aren't wonderful and they need attention but that can wait until I have them running. Other stuff to sort out first.

 

[Signal]

Thanks @Signal . Could you please tell me the thread diameter of that adjuster? Mocking it up here using screws instead of an adjuster to see what fits best, I found 6mm too small and 8mm diameter looks too big for fitting into the Kawasaki bracket. Obviously, yours fits perfectly, I think I need to replicate that.

The one on the cable in the photo measures close enough to 8mm, the one on the carb measures 6mm.
You can make adaptors like this out of bolts or cap crews if you have a lathe.

 

[Its been a long time]

The one on the cable in the photo measures close enough to 8mm, the one on the carb measures 6mm.
You can make adaptors like this out of bolts or cap crews if you have a lathe.

Thank you. That's good to know. I might order the adjuster from Venhill but I'll look at other options now you have confirmed the size you used.

Planning on removing the nipple off an XS650 cable and shortening the outer to suit. Slipping the adjuster on the cable then reattaching the nipple or a new one as required.

 

[Its been a long time]

6mm adjuster fits a treat with two half nuts. Now I'm ready to shorten the choke and throttle cables. I'll do the choke cable first as practice. I've never done cables before. What's the best way to cut the inner and outer parts of the cable? I'm thinking a Dremel with cut off disc is probably the best way for me to try.