CX500 GL500 650 Global

Well I just got a set of used carbs from makenzie71 over on CC's forum and need some advice.

For starters, they look exceptionally clean. In fact, they are so clean that I think I might try them as-is on my bike, that is if it were not for one minor detail. Just like carbs on my bike, one of these carbs has a broken mixture screw, so I'm thinking, why not yank the carbs from the bike and transfer good screw over to the set I just got?
Yes, I do mean no tear down, nothing - just transfer screw and bolt them up. Does this sound more like I'd be just (wait for it) screwing around or what? (sorry)

I've never touched carbs on these bikes so any thoughts here would help, including any other prelim adjustmensts you might suggest if I go with the above 'lazy boy' route.

Also, what's the easiest way to deal with the 'limiter' tab on the mix screws? It looks like I could buzz them off in a heartbeat with the whizzer or such - maybe there's a better/safer way?

Thanks

I've never had to take those silly limiter's off as they were never fitted to the UK/European models but whatever way you feel safe with.

As for the idle screws don't forget when they come out there should be a small spring on them then a small washer and if you are lucky a small and very important very tiny O-ring.Starting point according to all my manuals is turn in to carb body til they stop and then turn out 2.5 turns.When they are in the body/stopped I mark the outer edge with a felt tip pen so I know where I am.

People have had problems where the small o-ring has got stuck down the hole and or chewed.

Also whilst in your hands lift the throttle link and just see if the Butterflies lift pretty much at the same time to see if the carbs are close to being in sync.

HTH

Thanks for the tips, I forgot about the preliminary carb sync - THANKS

OK, I guess its my turn now!
#1: the easiest way to get that idle screw out is with the float bowl off. It will allow the limiter to turn easily. If it will turn, your lucky. If not, drill a small hole in it and use a screw extractor to back it out. YES, you can use one from the other carb. I recommend using the stock ones anyway. The after market ones are not as good as stock. When you get it out, take a file or a grinder to the tab and take it down a little. It doesn't take much to let it turn all the way around with every thing back together. As Shep said, make sure you get the assembly right on the idle screw parts. First on is the spring, then the tiny washer, and finally the tiny o-ring. I assemble it on the idle screw first, then with the carb held upside down, put it up inside and screw it in till it bottoms out. That way you know the O-ring is seated properly.

#2: Even though they are really clean visually, there are a couple key areas that need to be looked at. You needed to pull the bowls off anyway to change the idle screws, so spray some carb cleaner in the jets and clean out the bowls while your at it. What is inside the bowls should give you an indication of how the carbs were taken care of in the first place. Blow them out after to get all the carb cleaned flushed out so it doesn't eat up or swell any rubber parts.

#3: You need to pull the air cut off diaphragms out on the sides of the bodies to see whats inside and how the rubber is. I just took a really nice looking pair apart yesterday, and the diaphragms were filled with rust. You won't see that if you don't take the time to pull the 2 screws off and take a look. See if they have holes in the rubber also. If so, you can plug off the vacuum port hole in there to cancel out the vacuum leak when you are let off the gas. This is a common temporary fix.

#4: Do the slide pistons slide up easy or is there a bit of drag in one more than the other? If so, 2 screws out, and you can pull the piston out and clean them up with a bit of 0000 steal wool to smooth them up. Inside the piston top cover as well. Blow them or wash them out good after that to make sure no steal wool bits are still in there to get sucked into the engine. When you put them back together, make sure the black plastic ring is set in with the ridge facing UP. This limits the distance the piston can go down in the carb to let air through for the idle settings.

NOW, your ready to put them on and try them with out wasting a lot of your time. And I think along the way, you will find a couple things that will get your attention. It should only take an hour or so to do this preliminary check. And you will be a little more comfortable with your results if you do these simple steps first.

LRCXed wrote:OK, I guess its my turn now!

Hah! Feeling a bit spoiled by the personal service around here!

#3: You need to pull the air cut off diaphragms

Not that I won't replace the ACOD's, just curious:
What's the worst thing that could happen with damaged ACOD's? If it's just temporary lean condition on deccel and resulting popping/backrap through the pipes? (I can live with that - might actually enjoy it!)
Or does this have something to do with 'throttle overrun' ? I thought I saw Shep posting something to this effect, but so many carb related posts though - things are fuzzy

#4: Do the slide pistons slide up easy or is there a bit of drag in one more than the other?

Pistons move smoothly - no rocking or sticking.
Was wondering if they should 'return' to some neutral position on their own or are they just 'floaters'?

ONE OTHER THING -- What do you think about powder coating carb body (once its stripped) and or fuel bowls etc -- Parts would see oh, 400 degrees or so for maybe 45 - 60 minutes (I would meticulously mask all critical areas which would probably take the most time).

THANKS for the tips - YOU-DA-MAN!!!

I have been told that anything over 150 degrees will break down the integrity of the aluminum. I have not verified this, but I'm not going to take the chance on it till I find proof.

Damaged ACOD are not a big problem.You can bypass them with no ill effects.On one of my CXs I've used the smallest Metric leather punch out of the set I got to make my own gaskets,

http://tinyurl.com/5hufgj



and a bit of old inner tube and punched out a small plug and RTV'd carefully into the small hole but leaving the ACODs in.

I cannot find the link where I got this info but it works if you have problems.

LRCXed wrote:I have been told that anything over 150 degrees will break down the integrity of the aluminum. I have not verified this, but I'm not going to take the chance on it till I find proof.

Well, I should have worded that differently - sorry.

I've PC'd plenty of aluminum stuff and so far, so good, HOWEVER, I've yet to do anything as mission critical as a carb body.

My main concern is if there is anything that remains (deep) inside the carb body that could get buggered by heat. Do you know if there are any non-removables made of dissimar materials, things like bushings, lead plugs etc?

Although I haven't taken these carbs apart yet, I feel pretty confident about PCing the tops and bowls. Maybe I should do my spare set and give them to you for a review. I would do this -no charge of course- if you can send back replacements so I could (eventually) overhaul my spare carbs. If you're up for it, what are your thoughts on color?

Thanks again for you time - you've been a great help.

sheppola wrote:Damaged ACOD are not a big problem.You can bypass them with no ill effects.On one of my CXs I've used the smallest Metric leather punch out of the set I got to make my own gaskets,

and a bit of old inner tube and punched out a small plug and RTV'd carefully into the small hole but leaving the ACODs in.

I cannot find the link where I got this info but it works if you have problems.

These punches are also on my tool wish list. I image I can get some cheapies at my nearby junk tool store (China Freight)...

I like the inner tube Idea, I think I'll go that route.

Thanks for all your help Shep!

I don't like the idea of 150 Deg for the carb bodies but dunno :/