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Discussion Starter · #1 ·
Hi All,

I am working on a CX500 Custom for my stepson. Actually kind of falling for this bike, and might end up buying it from him...it needs the mechanical seal replaced and I know by the time I get done with that I will be firmly attached to the darn thing. Anyhow... right now I am working on the carbs.

I just finished cleaning the carbs per Larry's instructions in the wiki and it's running MUCH better, however it's still a little flat in the low end, and seems to be just running on the right carb at idle. When I turn the left mixture screw it has no effect even turned all the way in. If I put it back out to 2.5 turns and turn the right carb's mixture screw in it kills the bike at about 1 turn from the seat.

Does this indicate that I missed a blockage in the low end circuits or air passages of that carb, or could this be a balancing issue? Also... there is a tiny metal washer between the needle valve screw head and the spring missing on the problematic side. Does not seem to me that this should make a difference, but I am putting it before the experts.

On the subject of balancing carbs I have built a "two bottle method" balancer and need to figure out how to connect it to my carbs. I really don't want to buy adapters or wait for them to come in the mail. I am thinking if I can find a couple of brass screws with the right thread I can drill the centers out and make my own. Do you think having only a fairly tiny hole (1/16 inch) through the adapter will cause a problem? Anyone have another approach to DIY adapters?

Thank you!
yertman
 

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I used some brass tubing from a craft/hobby area at the hardware store. Threaded the end with the proper metric die, put on a nut and o-ring for sealing, and cut a slot in the other end for a screwdriver. Make them long enough to make it easy for access.
 

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Not an expert, but the adapters that came with my Morgan Carb Tune have a very small orifice. With just two cylinders to sync I think you could homebrew a sufficient solution. I love my carb tune but I did go through a few bikes before I could justify the expense.
 

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There is a tiny metal.... The spring is needed and a o-ring to seal it.
the spring puts tension on the valve, needle, from moving from vibration.
 

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I bought 5mm allen heads at Lowes and drilled them out with a 3/32 drill. 1/4 inch tubing fits over them nicely. I made a single U-tube manometer.
there are pics in a post from a week ago or so.
 

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Here's my manometer. Cost under $10. I bought the adapters at Grangers for a few dollars, although I had to order them and it took a few days. image.jpg
 
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Try screwing the needle right out and check if the tip of the needle has broken off, I had that problem with mine the broken tip got stuck in the carb, and I couldn't get it out, ended up with a new carb body.
 

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Search. Manometer.
The pics I was talking are in the, "Boy am I a dummy"

I studied the two bottle method. It seems the levels are not important, but are the levels changing. The single tube instantly shows which carb is pulling the higher vacuum. You can also check the absolute vacuum of each cylinder by disconnecting one side at a time. I just hold my finger over the vacuum port bolt. That is the one with the hole drilled through it. Quick simple and easy. By the way the water and the floats worked great. I also tried like hell to get it to pull water into a carb port. Even 6000-7000 rpms could not do it.
 

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Discussion Starter · #10 ·
Yeah. I have the spring, and I think on this model there is no o-ring just a little metal washer. I will double check when I take them off again now.

It appears that our local hardware store has a good selection of tiny metric things so I will take the washer from the other side and see if I can find a match.

Thank you!
Yertman
 

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Discussion Starter · #11 ·
This is what I did. I must have gotten hardened steel screws though, man they were not fun to drill through.
 

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Discussion Starter · #12 ·
Here's my manometer. Cost under $10. I bought the adapters at Grangers for a few dollars, although I had to order them and it took a few days. View attachment 22562
I made some that I am happy with but I didn't end up saving money or time. I used allen head screws and drilled through them with a 5/32 drill. Screws were hard and not easy to drill a straight hole through. Ended up going through 3 or 4 drill bits before I got two adapters made that I was happy with.
 

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Discussion Starter · #13 ·
Try screwing the needle right out and check if the tip of the needle has broken off, I had that problem with mine the broken tip got stuck in the carb, and I couldn't get it out, ended up with a new carb body.
On the carb model I have the tips almost look broken off, they just end kind of abruptly instead of drawing out into a long needle like they often do. I can see that they are not broken though because when the screw is all the way in the tip of the needle valve is actually visible blocking the idle jet / port right below the throttle butterfly valve.

THanks
Yertman
 
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