Topic: float pins stuck hard

[DM500K0]

Hi guys, first Q on this board. I have done a lot of searching and read every thread on this topic that I could find. This forum is an amazing resource. Still, I find myself at a loss as to what to do next.

The carbs are a set of 627Bs off a '71 CB500.  I have separated them and scrubbed/soaked most of the gunk away. There was little corrosion but lots of varnish, 1/8 inch thick in places.  All four slides are stuck in their bores, and all four pins are glued solid both to the floats and the stanchions.

I think the floats need to be removed before tackling the slides. I have been spraying the pins twice a day with Berryman B-12 carb cleaner for three days, but so far with no results. The floats will not move. The bodies are some kind of plastic, and I don't want to damage them. I've checked the prices for replacements.

So, what to do next? Seems to me the options are:

Ultrasonic bath -- this would be expensive as I would have to buy one. Worth the price (~$83 from Harbor Freight)?

Soak in lacquer thinner or carb cleaner -- might help, but will it damage the floats?

Heat -- pencil torch or hot (possibly boiling) water bath. From what I've read it looks like heat may be required to soften up the varnish. But again, I' worried what hot water will do to the plastic. I'm also worried about starting a fire with the torch!

 If you have used any of these methods -- or others -- successfully, please tell me how you did it. If you tried something that did not work, that information would be equally helpful.

TIA

Dave

[Finnigan]

I used a very small punch and then cleaned them more when they were out, pics are always of use on these threads

[underachiever]

For me, often times when something metal is stuck I kiss it with a soft flame.

Wash it down and let it dry first. Use a very gentle flame and keep it moving. You just need to soften the varnish enough to get the pin to move. Then hit it with a small punch. Pretty sure I had to do this with mine.

Use caution where fire is involved.

If you're unsure try something else.

Otherwise let it soak in some kind of penetrant.

[harisuluv]

you need some heat, try a hair dryer.  in your situation it might be worth it to get a gallon of berryman's chem dip.  you can get it at walmart.  I don't personally like to use it but.. you're not going to be able to rebuild your carbs with the floats stuck. 

That stuff is very good for varnish like you are describing.

Hair dryer should get it hot enough to where you will see the float actually drop as it releases.  Keep in mind that you may unstick the pin from the posts, and that is separate from unsticking the float from the pin itself.  If you are concerned about getting the non brass part of the float too hot you can construct a makeshift "heat shield" out of some aluminum foil or something. 

[martin99]

If you are concerned about getting the non brass part of the float too hot you can construct a makeshift "heat shield" out of some aluminum foil or something.

Soon as I read this I thought of several applications where knowing this little tip would have made a tricky job much easier. It's the simple things like this that never occur to you when you need them to. Harisuluv, nice one!

[iron_worker]

Be friggen careful with a punch! Those little posts don't take much abuse before they snap right off. I've seen it done 

IW

[Bailgang]

Be friggen careful with a punch! Those little posts don't take much abuse before they snap right off. I've seen it done 

IW

+1 in fact I'd keep a punch as far away from them as possible, I know because I got impatient myself with a set of 500 carbs and broke a post in the process and it was my tig welding wiz bro inlaw that saved me on that. The next try was on a set of severely varnished 550 carbs with slides froze as well as float pins. What I did that time was toss them in some boiling water, let the hot water soften the varnish up and I was able to remove the slides and patiently remove the float pins then tossed everything in a can of berrymans.

What ever method you choose the key is to BE PATIENT.

[754]

Make the heat shield out of at least 20 thou Aluminum.. Foil is too thin..

[MoMo]

a heat gun is your new friend but do shield the plastic from it....Larry

[skidooextreme]

pinesol for 2-3 days worked for me

[SOHC Digger]

The ultrasonic cleaner from harbor freight is a worthwhile investment. The larger one (the one you are referring to) has a built in heater. This is the same cleaner I use for my carb rebuilding service. Simple green, water, and the built in heat should loosen the pins and the cleaner will help with the rest of the carb parts too.

[Finnigan]

The ultrasonic cleaner from harbor freight is a worthwhile investment. The larger one (the one you are referring to) has a built in heater. This is the same cleaner I use for my carb rebuilding service. Simple green, water, and the built in heat should loosen the pins and the cleaner will help with the rest of the carb parts too.

I did the EXACT same process to clean my rack.  Took it all apart and did the bits individually one batch at a time, if you have a stubborn part increase concentration of simple green

[SOHC Digger]

Simple Green is fantastic, especially the purple industrial type, which can be found at Home Depot.

A word of caution though: Simple Green will discolor aluminum if you leave it in too long. Avoid soaking aluminum parts for more than an hour at a time.

[750cafe]

Perhaps one of my "How to" videos might help.
This procedure requires a $3.00 spring-loaded center punch.
Make certain that you get dead center of the float pin and try to support the near post.

Mikuni CV carb float pin removal

This one was a little less cooperative.

Mikuni carb float pin removal


Eric

[DM500K0]

Many many thanks everyone for all the tips!

Harisuluv, the heat shield idea is great.

For Scott (Bailgang), I have a specific question: How long did you boil the carbs before the pins came loose? The hot water bath idea appeals because there's a "built in" limit on the temperature. Based on your testimony that the floats were unharmed, I am minded to try your method.

Dave

[rb550four]

I always start off using a hairdryer... especially on stuck slides, put it on high, leave it blow until it loosens up. Remove when loose,then soak.
 Same deal with float pins... some can be really cruddy and difficult. in this case I use a soldering gun and warm up both sides of the pin and the tight spots on the float until it gets loose  move them around until they free up ,then work the pin ends and shaft close to the towers until they free up , then carefully slide the pin out. It just takes a little time.

[bjbuchanan]

The soldering iron is a good idea. Real small affected spot

[Don R]

Did you notice the punch sized black spot on that dude's thumbnail?  OW, bet the snap punch did that.

[lucky]

Hi guys, first Q on this board. I have done a lot of searching and read every thread on this topic that I could find. This forum is an amazing resource. Still, I find myself at a loss as to what to do next.

The carbs are a set of 627Bs off a '71 CB500.  I have separated them and scrubbed/soaked most of the gunk away. There was little corrosion but lots of varnish, 1/8 inch thick in places.  All four slides are stuck in their bores, and all four pins are glued solid both to the floats and the stanchions.

I think the floats need to be removed before tackling the slides. I have been spraying the pins twice a day with Berryman B-12 carb cleaner for three days, but so far with no results. The floats will not move. The bodies are some kind of plastic, and I don't want to damage them. I've checked the prices for replacements.

So, what to do next? Seems to me the options are:

Ultrasonic bath -- this would be expensive as I would have to buy one. Worth the price (~$83 from Harbor Freight)?

Soak in lacquer thinner or carb cleaner -- might help, but will it damage the floats?

Heat -- pencil torch or hot (possibly boiling) water bath. From what I've read it looks like heat may be required to soften up the varnish. But again, I' worried what hot water will do to the plastic. I'm also worried about starting a fire with the torch!

 If you have used any of these methods -- or others -- successfully, please tell me how you did it. If you tried something that did not work, that information would be equally helpful.

TIA

Dave

The more people pound on those pins the more they spread out and the tighter they get.

You need to get a steel pin punch and CAREFULLY push on the pin BUT put a backing block against the pin tower so it does not snap right off.

Sometimes you can file off the end of the pin that has spread out by people pounding on it.

You can try pulling on it or twist it with a minature vice grips. Then replace the pin with some brass rod from a model hobby store.

[trueblue]

I always use acetone first, it eats the varnish like nothing else.  If that fails I sitck them in a pot of water on the stove and boil them till they come free .

[tomkimberly]

I always use acetone first, it eats the varnish like nothing else.  If that fails I sitck them in a pot of water on the stove and boil them till they come free .

+1000

[DM500K0]

Again thanks to everyone who replied.

I got them all out, no broken stanchions. Here's how I did it:

1. One hour soak in straight Simple Green, room temp. Did not dare go longer.

2. Four days of spraying with Berryman's B-12 spray carb cleaner. Usually 3 times a day, then for a change a shot of Special Sauce (atf-acetone) on the last of my daily visits to the garage. I was careful to shoot not just the pin area, but also the bores.

3. Removed the link arms (had not done this earlier), in the process of unbending the flat washer 3 of the 4 slides came loose. They were not glued to their bores, the needles were glued to mainjet. The fourth came loose during the boil.

4. Boiled each carb in a large pot of water for 10 minutes.  After a 10-min. boil all the floats would move. Mounted the carb in a vise (I used wood shims to avoid marring the metal) and checked. With 3 out of 4 the pin was loose in the stanchions but still glued to the float. The other was glued to the stanchions. I gave the pin a shot of carb cleaner spray and then used a 1/16 inch center punch and pushed -- no hammer -- to try to get the pin to move laterally. I pushed in both directions. One refused to budge, another moved less than half a millimeter. Both of these went back in the pot for 10 to 15 minutes.

5. If I could push the pin sideways a few millimeters, I picked the side where it seemed to move farther and pushed it as far as I could. Then I clamped down on the protruding end with a pair of long nose 6-inch vise-grip pliers and started twisting the pin on its axis, while also exerting some lateral pressure to pull it out. The one part I was willing to maul is the pin. It took a few minutes and I had to reposition the pliers closer to the stanchion a couple of times, but the pin came out.

6. For the pins that did not yield on the first try, the second boil worked. The pins moved and I was able to extract them, as above.

Observations/tips/cautions:

I was not very careful about bracing the stanchions, either when pushing with the punch or pulling with the vise-grips. I am not a big guy and I backed off if what felt like a "good effort" did not move the pin. Depending on size and strength, someone else might easily snap one off while wielding the center punch, even without a hammer.

I bought an automatic punch, but a couple of trials showed that it required a lot more force to "fire" than I was willing to exert against the stanchions.

I was working on an unmolested set of pins. They had not been hammered on. Obviously boiling water would be useless against a splayed end.

Of all the good advice I got, the best was a single word: PATIENCE.

If your pins are stuck with varnish then it's a safe bet your jets and your needle valve are too. Pull or unscrew them as soon as you have the pin out, while the varnish is still soft. I figured this out after the second carburetor, but unfortunately I was not ready for the emulsion tubes. It looks like I will be boiling all the carbs again tomorrow.

Questions:

1. Would you kindly share your methods for removing stuck emulsion tubes? I have read many threads on this forum about these fascinating little devices, but the only extraction advice I found was either chopsticks or a brass drift, and knock 'em out from the top. I am reluctant to use brass against brass and there are no oriental food stores near my house. Anybody have another method?

2. Veterans/moderators of the forum -- should the above question be posted as a new thread?

Again many thanks,

Dave

[DH]

Go to a hardware store where they sell small diameter wooden rod, 5/16"
I use a small length of it, thru the top of the carb, and drive the needle jet
downward. Before you start, sharpen the dowel in a pencil sharpener to a size that best matches the jet without getting jammed either in the jet or bore. IIRC, the 500 carbs have the needle jet as part of the emulsion tube,
so its all one piece(?)...my results were obtained from 750 carbs, but I think my 550 carbs were the same as yours, and I was able to use the same method. Use care/light force, maybe a little heat. Use hardwood if possible. 1/4"or 5/16"

Credit to: www.salocal.com

[Black 750K8]

Make the heat shield out of at least 20 thou Aluminum.. Foil is too thin..

Think beer can

[rtbmrgl]

Make the heat shield out of at least 20 thou Aluminum.. Foil is too thin..

Brought up an old post, Member 754 had a great idea using a heat shield, made one from angle aluminum. Used propane torch, came out like butter.