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Discussion Starter · #1 ·
I am adjusting my valves and all of a sudden, when I start up the bike, raw fuel starts dumping out of the left carburetor overflow tube and I believe the brass overflow port on the interior side of the carburetor - I can't see it to be sure. Here is the thread regarding my valve adjustments. The last post is about my fuel leak.



http://cx500forum.com/index.php?/to...time/page__p__87831__fromsearch__1#entry87831
 

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Sounds like you could have a stuck float - this could easily cause the condition you describe. Just couble-check to be sure fuel isn't also coming from one of the two metal tubes that runs between the two carbs. If fuel is coming from one of the ends of these tubes, you'll have to separate the carbs and replace the small o-rings. This happened to me this week after the bike had been sitting a week.



If it's a stuck float, this could be caused by a couple of things (sometimes debris on the needle valve). If you get lucky, you can try to gently tab the carb(s) with a rubber mallot. This trick sometimes works if there's nothing major. If this doesn't work, you'll have to take the carbs out and simply remove the bowls to have a peek and possibly do some minor cleaning.
 

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Discussion Starter · #3 ·
Sounds like you could have a stuck float - this could easily cause the condition you describe. Just couble-check to be sure fuel isn't also coming from one of the two metal tubes that runs between the two carbs. If fuel is coming from one of the ends of these tubes, you'll have to separate the carbs and replace the small o-rings. This happened to me this week after the bike had been sitting a week.



If it's a stuck float, this could be caused by a couple of things (sometimes debris on the needle valve). If you get lucky, you can try to gently tab the carb(s) with a rubber mallot. This trick sometimes works if there's nothing major. If this doesn't work, you'll have to take the carbs out and simply remove the bowls to have a peek and possibly do some minor cleaning.


Well, there is fuel coming from the overflow tube for a fact, and I believe there is also fuel coming from one of the crossover tubes. I suppose I'll be pulling the carburetors soon. I am just concerned that this happened right after I started messing around with the valves. If I had set the intake valves wrong, could compression from the power stroke force fuel out of the carburetor?
 

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Discussion Starter · #4 ·
Whew, that's a relief. I tapped on the side of the float tank with plastic mallet - no more overflow. However, I did discover that the boot between the air box and the left carburetor is shot - a great big tear in the bottom. I'll pull it off and see about making a repair.



I think electrician's tape for now. I'll have to figure out a longer term repair. The shrink tubing idea may be the best.
 

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Whew, that's a relief. I tapped on the side of the float tank with plastic mallet - no more overflow. However, I did discover that the boot between the air box and the left carburetor is shot - a great big tear in the bottom. I'll pull it off and see about making a repair.



I think electrician's tape for now. I'll have to figure out a longer term repair. The shrink tubing idea may be the best.


Black rtv and old bike tube works well I have heard.



I have used rtv to seal small cracks in them.
 

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Discussion Starter · #6 ·
I taped up the crack in the boot with good, high quality electrical tape (Scotch 33M, the best!) and disassembled the plug caps to inspect the resistor, aluminum rod and spring. They were all in good condition. I cleaned some carbon deposits off of the junction between the resistor and the aluminum rod and took the bike for a spin. It is running much better. However, one cylinder still cuts out and when I got home, a little fuel overflowed, so I am probably going to pull the carburetors for a cleaning/inspection/synchronization.



All of this information is coming from this site and links to the CX500 GL500 650 Global forums - thanks for all of the good work and the documentation.
 

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Discussion Starter · #7 ·
Well, the carburetor overflow/leak has persisted. However, I have solutions in play! I have picked up an ultrasonic cleaner, ordered Larry's cool carb book, purchased a spare pair of carburetors and a spare airbox with pristine boots. Hopefully, by this time next week, I'll be back in the saddle. That is, if I can get the o-rings that I need from Harbor Freight.



Looking down the road, since I will have a spare pair of carburetors, I was wondering about setting up the second pair to use the air pods, rather than the intake box. What are the pros and cons of doing this?
 

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From what I've read on here about the pods on carbs, you will probably have to re-jet the carbs to account for them. The function of the air box is so touchy that even leaving the air filter off will hurt performance. Some even state that using anything but a stock paper filter, such as the KN oiled filters affect it. I had a KN on my former CX, and it didn't seem too big of a difference, so your situation may be different.



That's not to say it won't work, but almost all I've seen here is that it never will perform as well if pods are used compared to the stock set up.



Joel in the Couve
 

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From what I've read on here about the pods on carbs, you will probably have to re-jet the carbs to account for them. The function of the air box is so touchy that even leaving the air filter off will hurt performance. Some even state that using anything but a stock paper filter, such as the KN oiled filters affect it. I had a KN on my former CX, and it didn't seem too big of a difference, so your situation may be different.



That's not to say it won't work, but almost all I've seen here is that it never will perform as well if pods are used compared to the stock set up.



Joel in the Couve
as Ramp explained,pods in general can be a nightmare.

you must run with an inline fuel filter.

yes,your fvn,s are not shutting off the the fuel when your bowls are filled to the correct level.
 

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Discussion Starter · #10 ·
as Ramp explained,pods in general can be a nightmare.

you must run with an inline fuel filter.

yes,your fvn,s are not shutting off the the fuel when your bowls are filled to the correct level.


Yes, I intend to install an inline filter after going through the carburetors and installing the new/used airbox with good boots. The big rip in the boot on the left side has got to be wrecking the intake tuning.



I guessed that would be the answer regarding the air pods. I may play around with them in the future, including rejetting, etc. It is not that I am adverse to the airbox - I just know that the boots are in limited supply and I am trying to think of solutions. I don't know that we could easily reproduce this formed rubber piece from common supplies.
 

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There have been several posts about pretty simple repairs to the boots. The one that seems at the top is a high quality heat shrink tubing around the boot, then a hair dryer or other moderate heat source to shrink it around the entire boot. Even bike tire inner tubes have been suggested, along with Shoo Goo and RTV. It is hard to find decent replacements, so repair seems the most cost effective means to the solution to this air leak issue.



Joel in the Couve
 

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Discussion Starter · #12 ·
Well, these carburetors aren't rebuilding themselves. I have practiced on a spare pair, only to find one float, possibly two, are missing from the tanks. I will go through the second one quickly to verify the existence of the second float. Then, I suppose I'll remove the ones on the bike and go through them, taking advantage of the experience that I have gained through this excellent site and my own efforts. Here we go!
 

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Well, these carburetors aren't rebuilding themselves. I have practiced on a spare pair, only to find one float, possibly two, are missing from the tanks. I will go through the second one quickly to verify the existence of the second float. Then, I suppose I'll remove the ones on the bike and go through them, taking advantage of the experience that I have gained through this excellent site and my own efforts. Here we go!
thats the real beauty of having spare parts/and or a parts bike


good luck
 

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Discussion Starter · #14 ·
Dunno about this second spare carburetor. Here is the float bowl fuel drain screw:







The interior of the throat/slide area and the jets:







Here is the float tank, minus the float. Wierd!







I will clean all of the parts and will polish and reassemble complete over time. Once I get these all through the ultrasonic cleaner, I am starting on my running carburetors.
 

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Discussion Starter · #15 ·
thats the real beauty of having spare parts/and or a parts bike


good luck


Yup - I'll slowly build an inventory as funds permit!
 

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that float has not vanished.someone knows where it is/was.the last person to mess with the carbs did not,for whatever reason fail to re-install it.i should forget about it.

the carbs themselves do not look that bad,i see much worse every day
 

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Discussion Starter · #17 ·
Well, the carburetors are off the bike and the left one is disassembled, awaiting the parts washer - still cleaning up the second spare carburetor. Upon removing the float, the problem was revealed - the float, well, she no floats; she is water logged. I guess the seam is split or there is a crack or hole somewhere.



So, do we repair floats?



Here are some pictures of my progress.



















I have lubed the throttle and choke cables while I have the ends turned loose. I am replacing the airbox for one with two good boots as well. While the carburetors are cleaning, I will wipe down the frame and swing arm as best I can. When I drained the airbox drain tubes, the left tube had some liquid in it, mostly fuel, while the right tube also had fluid, mostly oil. What do you guys think?
 

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The drain tubes, normal.



If you have, or can get some, use some ACF50 on the frame linkages whilst you are wiping down things. You might try using a little moly grease in the bushings, but the ACF will suffice for a good while, until such time as a full on rebuild.



That float drain bolt was pretty crapped....looks like a lot of moisture got involved along the line.



Joel in the Couve
 

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Discussion Starter · #19 ·
That float drain bolt was pretty crapped....looks like a lot of moisture got involved along the line.



Joel in the Couve


Thanks for the reply, Joel. I will lube up the frame linkages. I am trying to source some ACF50 through work, but didn't get a quote last week. I have a little antifreeze leaking out of my weephole, so I know that I will be back into this area for more work this fall and winter and will have the motor out to fix the seals - that's when I will probably hit the frame linkages with some ACF50 - it looks like really good stuff.



The float drain bolt you referred to is from my spare carburetors that I purchased to rebuild and put on the shelf. I tore them down for practice prior to working on the carburetors on my bike. The carbs on my bike are in much better shape - the rubber is better, the jets are cleaner, everything works better, with the exception of the left float being full of fuel. Any ideas on what to do with that float? Replace? Repair?
 
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