Ninja EX500 carbs on an XS650?

[Its been a long time]

Thank you, very helpful.

Good luck. Unfortunately I don't have full confidence in that without disassembly of the carburettors and measuring up myself. Should be a starting point though. It's probably a job I will have to do before much longer. I'm close to finally installing the ER5 carburettors now.

 

[650Skull]

I would like to replace the solid fuel tube O rings on my carbs. Part number 92055 in diagram.
View attachment 345077
they are a simple O ring does anyone have the dimensions.
They do swell up after a while and stop leaking, but after a few weeks of sitting they shrink and leak again. Very frustrating if you just want to go for a ride on a nice day.

When I did my BS34's they were leaking at the t join. People say the plastic coating will swell to stop it.
Not knowing this I cut a groove in the valley and got a fuel resistant rubber O ring from the local engineering shop. It worked. Couldn't tell you the size just took the t in and got a couple then carved away til they slipped into the carb.

 

[Its been a long time]

Just about ready to fit the carbs. Short choke cable isn't perfect but for what it does, it's fine.

 

[Its been a long time]

First fitting of ER5 carburettors. The single outlet reed valve breather makes a bit more space between the cylinder head and the carburettors. Definitely recommend one to anybody doing this conversion. Everything fits OK. I'm going to move the Boyer Bransden ignition box from behind the steering tube to the left side of the battery box provided it clears the side panel. Never been happy with the BB box up where it is, I'll be a lot happier making a rubber mounted alloy plate for the BB box to locate on.

Picture -

 

[Adamc]

First fitting of ER5 carburettors. The single outlet reed valve breather makes a bit more space between the cylinder head and the carburettors. Definitely recommend one to anybody doing this conversion. Everything fits OK. I'm going to move the Boyer Bransden ignition box from behind the steering tube to the left side of the battery box provided it clears the side panel. Never been happy with the BB box up where it is, I'll be a lot happier making a rubber mounted alloy plate for the BB box to locate on.

Picture -

View attachment 345566

Nice job, and it looks proper.

 

[Its been a long time]

Nice job, and it looks proper.

Thank you. What I especially like is that if you don't know XS650s very well, it looks like it left the factory that way. Of course, soon I'll know if it runs or not!

 

[Its been a long time]

Problems routing the tubing from the fuel taps to the single inlet on the ER5 carburettors. The fuel taps are 6mm and the inlet on the carburettors is 8mm. But that's not really the problem. In the picture below I have the tube connected to the carburettor inlet. There's no way I can get fittings in there from the rearward facing fuel taps. I think I am going to have to replace the cross brace at the back of the carburettors with a top brace like the BS38 Mikunis. I was thinking of doing it anyway because on my bike the cross brace is hard against the rear frame down tube. I think if I remove the rear cross brace I might be able to orientate the inlet to the carburettors facing towards the rear of the bike. Then run the 6mm tubes from the fuel taps further back and join to a single 8mm tube behind the down tube but in front of the battery box.

I am very curious how others have approached this problem, it's more than a decade since the thread started. Am I the only person who has found this problem? I can't be the first. What have other owners done please? Thanks.

Picture -

 

[Signal]

Did you cut a relief in the centre of the cross brace for the rear down tube?
I cut mine quite a lot and then welded a brace on the other side , then zinced plated it. That and the removeable air filter extensions make fitment a lot easier.


I have 2 ideas that might help with the fuel line mis match.
The first is make an adaptor that goes from the tap fuel line size to the CVK fuel line size. I did this on my road bike. Photo below.

The only part visible of the adaptor is the aluminium ring to the left of the hose clip.

The second more complicated and with possible drawbacks is I made a fuel rail that mounts under a motor breather cap screw. This is for my tracker that has a 2 fuel taps. It also has a drain at the low end when the bike is on the side stand. My tracker has a fibre glass tank and I will be draining the fuel after each ride.
The possible problems are fuel aireration and warming from the mounting of the rail. I have not tested this system yet apart from a brief start to check the ignition timing.

 

[Its been a long time]

@Signal Thanks very much for the reply. Yes, I notched the cross brace to the extent that the part between the carburettors is no longer an angle, it's flat. Even then, the cross brace is hard on the rear down tube. I suppose there's a fairly wide manufacturing tolerance on the frame. Mine is very tight indeed. Touching quite hard. Paint has already rubbed off, along with the self adhesive foam pad I used there. I think I'm most probably going to have to make a top brace between the carburettor tops to enable removing the back cross brace.

Your fuel rail idea looks great but my fuel taps point the wrong way, but it's given me an idea. In anticipation of an issue, I have bought a number of 8 and 6mm tube fittings in brass. I think I might be able to use a T or a Y piece (6 x 8 x 6mm) as a pseudo fuel rail but in front of the battery box. Then using 6mm fuel line running back to it from the fuel taps outlets. Then come forward and down from there in 8mm to the carburettor inlet. That might work.

I was going to relocate the Boyer Bransden box in front of the battery. I don't like where it presently is. Looks like I'll have to revisit that idea again.

Thanks again, input is appreciated.

 

[Its been a long time]

I think I've a way forward now with running the fuel lines to the ER5 carburettors. I am going to use a 6 x 8 x 6mm T behind the rear downtube. And run the 6mm fuel lines back from the taps to meet the T. A short 8mm tube will run down from the T to the carburettor inlet. It's very tight, the fuel inlet is very close to the rear down tube. I'll take some pictures when I've done it.

Next problem. Am I the only person who has tried to use standard XS650 side panels with the ER5 carburettors? Picture below is the right side. It looks like the side panel is going to fit. But it's deceiving. The panel retaining toggle at the bottom of the panel is about 6.5cm away from engaging. There's a hard clash between the pesky rear cross brace, screws, possibly the float bowl and the leading edge of the side panel. If I remove the rear cross brace as planned. The panel might fit. It might not. It's going to be very close. The left panel I haven't taken a picture of, it's a much worse clash on the left side.

Oh dear.

 

[Signal]

This is not a problem with Special sidecovers. This conversion looks to be fighting you all the way. The first thing I can think of is replace the clip fitting with a longer one, however it may look odd with the covers splayed out at the bottom.

 

[650Skull]

Buy a couple of secondhand ones. Cut to suit. Nobody will notice if the cut is balenced

 

[Its been a long time]

This is not a problem with Special sidecovers. This conversion looks to be fighting you all the way. The first thing I can think of is replace the clip fitting with a longer one, however it may look odd with the covers splayed out at the bottom.

Yes, that'd fix it but look dreadful!

 

[Its been a long time]

Buy a couple of secondhand ones. Cut to suit. Nobody will notice if the cut is balenced

I might just have to do that. Getting a set decent enough and not costing a fortune might be an issue. But thanks, I hadn't thought of that actually.

I'm thinking that at the front of the covers where the steel is flared out to clear the carburettor rubbers - If that were chopped and the front of the panel made flat that would do it.

 

[arcticXS]

What about taking a mold from a pair of stock covers, and making fiberglass copies?

 

[Its been a long time]

What about taking a mold from a pair of stock covers, and making fiberglass copies?

Yes, great idea. Or scanning and 3D printing?

 

[Its been a long time]

Seems somebody already scanned the side panels and prints them in ABS. About £100 a pair. Looks like a pair of original used steel ones are at around £70 -

 

[Tony g]

Re the fuel taps facing the wrong way, will the taps fit backwards left to right ?

 

[Its been a long time]

Re the fuel taps facing the wrong way, will the taps fit backwards left to right ?

Yes they will. I considered that. Overall, the idea I borrowed as suggested above of having a 6 x 8 x 6 T behind the frame rear down tube, in front of the battery box fixes my problem. Thanks for the input though, appreciated.

 

[Its been a long time]

It's been a long time (I think I'm spotting a trend here)

But I now have the 650D running on CVK34 carbs. Started first button press on full choke, responds well to the throttle, was able to remove choke after a few seconds and set idle speed on the adjuster. Left cylinder is running just fine. Right side isn't running so well, muffler only got half as hot on the right side and is obviously misfiring back through the carb with a sharp "crack" noise. I think there's probably an air leak.

Early days, but promising. Will try again later with my carb balance gauges connected.

I need to check the running ignition timing but need to sort out the misfiring right cylinder.