xs650dreamer
XS650 Junkie
maybe you have you floats upside down. when you put the carb right side up the floats should fall down a good amount and pivot up to the needle
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Ninja EX500 carbs on an XS650?
- Thread starter Highside
- Start date
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- Tags
- cafe carburetors custom engine
troopthrowback
XS650 Addict
I tried to put them in upside down and couldn't. There are tabs in the floats that interfere with the jet block so it's idiot proof.
troopthrowback
XS650 Addict
The pop is not through carbs but through exhaust. As in too leak a mixture. This occurs just before it dies every time, presumably the floats emptying faster than they can refill with my severely restricted fuel inlets.
xs650dreamer
XS650 Junkie
yea man i think you have your floats set wrong. did you use the clear tube method?
troopthrowback
XS650 Addict
So here's what I'm thinking now. Many ex500 owners say that leaks can be a result of the o-rings between the carbs being faulty. that makes sense, but doesn't sound like the cause of my problem since I do get a good, leak-free seal with the blow test. If it were an actual leak I would get air leaks as well. Considering I don't get leaks, jsut floats that don't seat under the pressure of fuel in the lines, this makes sense, see reply #3:
http://www.ex-500.com/index.php/topic,42658.0.html
I'm running a 3/8" diameter fuel line to the "T" connector that feeds the carbs because that's what I had around that fits that monster inlet barb. It turns out the cvk for the ex500 calls for 5/16" fuel line as standard. The increased volume of fuel stacked on top of those very sensitive float needles is enough to unseat them and cause them to leak.
Since I have no other idea what it could be, I'm going with this. Off to pick up some 5/16" fuel line!
http://www.ex-500.com/index.php/topic,42658.0.html
I'm running a 3/8" diameter fuel line to the "T" connector that feeds the carbs because that's what I had around that fits that monster inlet barb. It turns out the cvk for the ex500 calls for 5/16" fuel line as standard. The increased volume of fuel stacked on top of those very sensitive float needles is enough to unseat them and cause them to leak.
Since I have no other idea what it could be, I'm going with this. Off to pick up some 5/16" fuel line!
Where does it leak from? If you can measure bowl level with the clear tube method they must somehow not leak at some point? I doubt the volume of gas makes that much difference, unless your tank is half a mile above the carbs.
Does the vent tube work? It's the plastic T not connected to anything. When my needle valves were bad that is where gas was pouring from BTW.
+ 1 on "please take pics", might be quicker for us.
Does the vent tube work? It's the plastic T not connected to anything. When my needle valves were bad that is where gas was pouring from BTW.
+ 1 on "please take pics", might be quicker for us.
troopthrowback
XS650 Addict
From first post^^^.
According to the ex500 guys 3/8" line is a sure cause for float needles not seating. I'll post up progress when I get the line swapped. Watching "On Any Sunday" with my 3yo to pass time till my wife gets back with my truck keys (oops!).
Like my last rounds with adjusting these floats I set them so close to closed that it was restricting the flow so much the bike would lean out while running even while "leaks" were still present.
troopthrowback
XS650 Addict
From the ex500 board linked above, for reference:
recently i had some issues with the bike, and as part of the fix, i pulled and cleaned the carbs. when i put them back on, i noticed a fuel leak (seemed to be dripping off both of the drain valves, though very slowly). I had this same problem when i first put the bike together, and the fix then was using a hose clamp where the fuel line meets the carb. so i did the same thing. however, with the carbs and airbox on the bike, i had some difficulty tightening the clamp. Im not sure if this slowed the leak down any, but still leaking either way. since i believe i installed the hose clamp on there tightly enough, im looking for other sources for the leak. The bike will start instantly with no problems even after sitting a day or two, so i think i can safely assume the leak isnt from the drain valves (suppose its possible its from the bowl o rings, but would they both start at once? they also looked in good shape when i opened up the carbs, and they looked seated right). any other places it could leak?
Response:
the 3/8 line is almost a certainty to leak, its simpy too large for the rail. Cranking on a clamp will lead to twisting, crimping of the line.
the 5/16 is the way to go.....use spring type clamps with it (required as the OD is larger than stock) very easy to work with
auto parts store.... regular (non fuel injection) 5/16" ID (spring clamps pictured)
recently i had some issues with the bike, and as part of the fix, i pulled and cleaned the carbs. when i put them back on, i noticed a fuel leak (seemed to be dripping off both of the drain valves, though very slowly). I had this same problem when i first put the bike together, and the fix then was using a hose clamp where the fuel line meets the carb. so i did the same thing. however, with the carbs and airbox on the bike, i had some difficulty tightening the clamp. Im not sure if this slowed the leak down any, but still leaking either way. since i believe i installed the hose clamp on there tightly enough, im looking for other sources for the leak. The bike will start instantly with no problems even after sitting a day or two, so i think i can safely assume the leak isnt from the drain valves (suppose its possible its from the bowl o rings, but would they both start at once? they also looked in good shape when i opened up the carbs, and they looked seated right). any other places it could leak?
Response:
the 3/8 line is almost a certainty to leak, its simpy too large for the rail. Cranking on a clamp will lead to twisting, crimping of the line.
the 5/16 is the way to go.....use spring type clamps with it (required as the OD is larger than stock) very easy to work with
auto parts store.... regular (non fuel injection) 5/16" ID (spring clamps pictured)
troopthrowback
XS650 Addict
Positive. Everything is flowing clear. I'll take pics asap. Just moved it all into the shop since it's raining here in NorCal at the moment. Garage too full of projects (3x 1980 xr80, 1x 1974 z50, 1x 1973 xl350, 1x 1976 175 enduro)
troopthrowback
XS650 Addict
Okay, back to the drawing board. The line I was running was actually 1/4" I.D. tried even constricting that with a hose clamp to reduce the column of fuel over the float valves. No dice, still flowing gas unimpeded.
Some photos for your viewing pleasure. What's wrong here?
Fuel flows from here on both carbs:
Some photos for your viewing pleasure. What's wrong here?
Fuel flows from here on both carbs:
troopthrowback
XS650 Addict
I thought I'd read somewhere to cap that one! So leave it open to the air?
troopthrowback
XS650 Addict
Excuse me, running out to the shop. I'll be right back...
troopthrowback
XS650 Addict
Hallelluia!!!! That was it. Literally fired 1/3 way through first kick. Set mixture screws at 1.5 turns from closed. Purrs like a kitten and great throttle response. This was all on the center stand, of course. Put a stop to my rejoicing before I asphyxiated in my underventilated garage. Thanks for the help guys. Now if you ever need help with adjusting ANYTHING on these carbs I'm an expert at their internal anatomy...
I literally can't wait for some sun outside to take it for a rip. Ride report within 48 hours...
I literally can't wait for some sun outside to take it for a rip. Ride report within 48 hours...
scabber
XS650 Guru
Good eye Maurice. Problem solved.
troopthrowback
XS650 Addict
Credit where it's due. I'm indebted, Maurice. Thank you for your keen eye and attention to detail.
xs650dreamer
XS650 Junkie
so simple 
thank goodness for the pics
thank goodness for the pics
You say you got frustrated enough to chuck the carbs after just 6 hours of working with them. Maybe you have the wrong hobby. 6 hours ain't nothing.
It often takes a long time to get carbs right. When I first started with carbs it took removing and cleaning several times, an hour or so each time, just to get them clean, then even more times to adjust jetting and other adjustments.
I'm better at it now, but it still takes time.
Be a bit more patient.
Now that you have them right, was it worth the time?
Leo
It often takes a long time to get carbs right. When I first started with carbs it took removing and cleaning several times, an hour or so each time, just to get them clean, then even more times to adjust jetting and other adjustments.
I'm better at it now, but it still takes time.
Be a bit more patient.
Now that you have them right, was it worth the time?
Leo
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