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Discussion Starter · #1 ·
Have been doing a lot of search and work on the carbs. I have a right cylinder that is running rich, and lags at idle. The engine seems to work to idle at 1500 rpm after some adjustment, but its running on one and the right cylinder loads up. Oh if I shut off the petcock while running, the idle smooths out, the dead cylinder fires nicely, and it will idle like a sewing machine. Very frustrating.



I have checked the float height, and set it. I went to high as now I have starvation at 70 mph, surges a little.



But always idles somewhat poorly, right cylinder is definitely the culprit. I have cleaned the carbs, set the pilots to 1.25 turn out, and worked with the float heights. I had them set right at one point, but the poor idle always happens.



Tonight, I did the poor mans synch, pulled the left plug cover, and it struggles to start, and tries to idle at 750 rpm and dies off.



The right plug cover pulled (to let the left cylinder fire. The bike actually idles at 1500 rpm, and idles nicely on the one cylinder.



Synch it (after I reset the floats, again)? If so which way do I turn the screw to adjust.



My concern is the fact that ever since I rebuilt the petcock, it has done this. Did I damage the diaphragm? It acts as it should, no fuel shall pass unless the vacuum is operating (bike running, but it does shut off too.



Its is really wet if I let it idle in the right cylinder, and my mpg STINKS. went through 2.0 gallons of gas in 30 miles.



Help please?
 

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2 gallons in 30 miles? Sounds like a leak... Also, make sure the ratio screws are tightened down tight, the turn out 2-2 1/2 turns out, make sure your jets are in the right place... Also make sure the floats are set right, they have to be RIGHT on the money
 

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You may have damaged the diaphragm, it could be sucking fuel through the vacuum line into the right cylinder.

You could test this by blocking the vacuum nipple on the right side carb and setting up an alternate fuel supply and see if the bike runs correctly.
 

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Discussion Starter · #5 ·
Okay, so immediately AFTER I cleaned the diaphram with high potency carb cleaner, I read why that should not be done, I have had this problem ever since. I have been wrestling with the floats and now they are too high, and I have to bend them back down. I fixed the carb leak, it used to piss itself all over the ground, and now it does not, its just eats the fuel and is likely causing a gas oil issue in the crank, yea....



Anyway, here is the sequence of events, and I think Allan is spot on.



Son borrows bike. Son returns bike, and as usual son breaks something as the damn thing just does not sound right.



Dad takes bike to gas station sees gas in tank, and counts on getting to next town.



Dad breaks down on freeway (details of this belong in a different post and in an area that allows an extreme amount of cussing)



Dad rebuilds petcock, and bike starts to pee all over itself, but only when running.



Dad rebuilds carbs, three times, I have done this a lot, and I HATE Keihin as they can be picky as hell. The seats are cleaned, I tugged on the spring shaft gently, I scrubbed with tooth past and metal polish, the floats do their damm job, it does not leak, and it runs beautifully when the petcock is shut off.



Same pattern described above, no matter the floats setting, no matter the air setting. Same result, only it runs SOOOOO much faster with the pilots at 2.5 turns. By the way that is where I set all of my carbs on all the bikes. I own a few Hyosungs GV650's, and I just sold my evo softail. Not a Newbie, just new to this forum. This is like my 50th purchased bike (seriously, I picked this one special, I love the cx500, and once owned a mint cx650 (man I miss that bike). I have ridden for over 35 years now.



Every-time it runs, the right cylinder intake is DRIPPING gas abnormally wet, but the bike DOES NOT leak.



I shut off the petcock, and (I timed it) 5 seconds later, the rpms pick up, both cylinders are running, they are dancing in a unique balance of a flying vee ballet we all love so much for the 15 seconds it can idle on a full bowl. Sounds so sweet, it makes you want to cry.



Last night, I also migrated the floats. I thought, if it a bad float, the richness will follow itself to the left cylinder, and I can pick on that side for a while. Nope, no luck. None.



So I agree, I have to set up the Alt Fuel source, maybe do a synch which makes no sense as I am spot on with my bench synchs.



I damaged the diaphragm



3 questions:



1) Can I plug the vacuums and call it a day until I get a nice pingel set up on this tank?



2) Where can I buy new floats in case I break these bringing the heights back down?



3) So I need a consensus on this, is it 2.5 turns out, or is it 1.25 on the pilot screws? I have read threads with both recommendations.
 

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Apparently you can rebuild the vacuum petcock with the diaphr am spring on the opposite side of the diaphram so they will supply fuel without vacuum.



You would also need to cap the vac. port on the carb.
 

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Which carb is the vacuum port on?



Has anyone ever heard of a mode of vac. petcock failure that allows fuel to be drawn through the vac. line?
 

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Discussion Starter · #9 ·
ALWAYS...NO WAIT NEVER USE CARB CLEANER ON A DIAPHRAGM. I know it was wrong when I did it, but thanks guys for straightening me out.



Alln, where do I send the beer, and CXPHREAK, may take a while to get there, but I would send you some too.



I have that wondrous symphony of Flying v-twin running in that manner in all rpm ranges. Now I just need to straighten out the pilot screws (going to trim the bowls so I can turn them without having to pull the carbs too, little tired of pulling the carb bank. I will set it to 2.5 like I always do and see what he does from there. Now I can go back to the DR8ES plugs too.
 

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Discussion Starter · #10 ·
Which carb is the vacuum port on?



Has anyone ever heard of a mode of vac. petcock failure that allows fuel to be drawn through the vac. line?






I have !!!!

Vacuum Petcock Failure due to bad mistake. I put the spring on the other side of the diaphragm, put vacuum plugs on all the leads, and boom goes the dynamite, I got my baby back.
 

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. . 3) So I need a consensus on this, is it 2.5 turns out, or is it 1.25 on the pilot screws? I have read threads with both recommendations.




The manual says 2 turns as a starting point. (just my 2 cents)
 

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If the idle mixture screws have little or no effect it's a sign that there's more work/cleaning required on the slow speed idle circuit in the carbs.As always when doing anything to the carbs it's easy to introduce new problems when re-fitting the carb boots e.g air-leaks and bad clamps or munging the boots onto the carbs.
 

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Discussion Starter · #13 ·
The manual says 2 turns as a starting point. (just my 2 cents)


I am at 2.25 out now. No starving up top, the floats are good. No leaks, and it holds 80 very well now. Much stronger with the clean jets. No seapage. It also has that nice water drip back from the exhaust.



Yea, it did 40 miles, no issues, ran strong, running a little warm, but I was running fast into the wind, and I have to get those cooler plugs now.



I feel good about the bike now, and I think its a keeper.



Will make a fun trike for the wife.
 

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Discussion Starter · #14 ·
I am at 2.25 out now. No starving up top, the floats are good. No leaks, and it holds 80 very well now. Much stronger with the clean jets. No seapage. It also has that nice water drip back from the exhaust.



Yea, it did 40 miles, no issues, ran strong, running a little warm, but I was running fast into the wind, and I have to get those cooler plugs now.



I feel good about the bike now, and I think its a keeper.



Will make a fun trike for the wife.


I caused the whole issue. I have the modded petcock now, and I am putting a Pingal on it this week.



I use lemon juice boiling so I know I got everything. Runs better than new, brings back a lot of memories from a long time ago, this is not my first cx. I love this bike now though. Runs out extremely strong, and I think the cleaning and new settings will help with the previous mileage too. I was only getting 35 on the freeway, there is a lot more available throttle now, and it is very responsive. I ran with a CTX for a long time until he got tired of me. Thats a fast cage.
 
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