Stuck Float Pin Hinge Pillars

So I found a bank of carbs that needed a little attention. Seeing as they are extras theres little need to rush. Cool...right!?
NO...not really. I opened all float bowls and half a bowl of varnish slowly sludges out.
No biggie, but then I relize I can not get the hinge pins out. The floats dont move either, seized with the pin I assume.
Almost all thye other fasteners are screwed :lol: but this one seems like a doozie. Any advice???

 

Several cans of brake cleaner should free them up! Be prepared to get messy!! ;-)

 

I use carb cleaner to slowly "work" the float hinges first, so they move at least a little bit. Then I grab the mushroomed end of the hinge pin with some small but grippy pliers and "twist" it out. That way the pillars don't break :-D

 

Last week I took my carbs apart that had been sitting for at least 17 years. I also found stuck float pins along with lots of other gunky stuff. For the pins, I had a pin punch small enough to drive the pin out, and on the first carb I attempted to tap the pin out with a tiny tappy hammer. The stand broke, so I abandoned this process. Next, I went to the vise and used a deep 1/4 drive small socket to 'receive' the pin and ground down an old junk screwdiver to use a a short pin punch. Set it all in the vise and apply gentle pressure and the next three pins came out smoothly. It helps to have an extra set of hands to hold it all in place.
Of course, everything had been sprayed several times with carb cleaner, but I don't think that really did much good.
Just be patient, take your time.

 

I was going to suggest soaking the individual bodies in carb dip, but I don't know how well the floats would react. Might want to do that anyway once you get the floats off.

 

pb blaster just a tiny spritz and let them sit. You may even want to spray it in a cup first and just use a drop if you have any rubber compenents left in the carbs. Brake fluid itself is a great creeper into rusty places as well but hard on some surfaces.

 

Getting stuck Float Hing Pins out is Bomb Squad work.
One false move and it costs you the Carb Body when the Float Hinge Pillar Snaps.

I use two simple tools:

A set of large Diagonal Wire Cutters that I deliberately "Dulled" to make into my "Grab Tool"
I opened the Jaws and "Shoe-shined" the cutting edges with some 600 Grit Finishing Paper.
Took the cutting surface off them so they wouldn't cut through the Hinge Pin when I grab one.

Small Ball-Peen Hammer Head -- NO Handle!
Without a handle on the Hammer Head you can apply precise Impact to the Diagonals when you grab onto a Hinge Pin.
The Diagonals are wedge-shaped; too.

As the Pin moves ... you grab it closer to the back of the Jaws on the Big Dikes and apply Impact to the Dikes with the Hammer Head.

 

Might try to boil the assembly (stripped as far as possible) in lemon juice. I read a few success stories here in the past two months.

 

Are these Hitachi or Mikuni carbs? I ask because the float pins on the Hitachis, as I remember, don't have nail-type heads on them.

 

HiTots.
I have been coating with carb cleaner, wait until evaporation occurs, then hit it with some penetrating oil.
This has allowed one of the floats to "hinge" abiet with some convincing.
Trying to keep from braking anything, so I am proceeding at a snails pace.
Float needles are stuck inplace thanks to years of varnish too.

 

ok, who knows the heat and ice technique off the top of their head?
floats will now pivot but the pin does not want to release.

 

duuuuurh I didn't even think of that. I just got through rebuilding two sets of Mikuni's, so they were kinda stuck in my mind :lol:

I was thinking though... What if you take a small aluminum block and cut two slots in it so that the float pillar tops would snugly fit in the slots, and then use said aluminum block as a prop/reinforcement while you punch the pins out?....

 

I used a piece of metal from a "nail stop" that I wedged between the posts when I was removing the Mikuni float pins. And photographed it. And stuck it in the updated writeup.

No, you're not the first person to think of this. Mentioned it to Chacal. Apparently, the spacing between the pillars differs between different models of Mikunis.

Interesting approach, though. I was also considering using some sort of c-clamp setup. Perhaps put a small socket on one side to receive the head of the pin...

 

It sometimes helps to shave-off and burrs that might have formed on the ends of the Hinge Pin with a Dremel armed with a Cut-off Wafer.

Remove 10-thousandths off the end of the Hinge Pin and it doesn't get caught trying to get forced through the hole in the Pillar.

On severe cases the Hinge Pin is rusted-out BETWEEN the two Hinge Pillars and the Pin is hopelessly captive because the Outside Diameter of the Hinge Pin has swelled-up with oxidation that will not pass through the hole in the Pillar.

Should that be the case ... there is no alternative but to sever the Hinge Pins on the insides to be able to lift the Float Assy out from between the Pillars.

You are much better off cutting the Hinge Pins and continuing needing new Hinge Pins than you are placing the whole Carb Body at risk of being ruined by having a Hinge Pillar fracture and render the Carb Body useless.

 

I never said I was the first
I do have an idea for an easy to use, adjustable support tool just for stuck hinge pins. I'll try to muster something up once I dig up one of my trashed sets of carbs.

Are you talking about your Hitachi carb breakdown writeup?

 

You might want to try a heat gun applied to the carb, not the pin. The COE of aluminum is much greater then the steel pin, it should expand releasing the pin.

You can use a torch if you are careful, maybe even a soldering iron.

 

Whatever is is that you fashion to press-out those Hinge Pins ... be sure to
fabricate something to negate any thrust on the Hinge Pillars.

Those Pillars are Cast ... NOT Billet!
They aren't designed to take any lateral movement what-so-ever!

The slightest force to move them off-center will result in the Pillar fracturing and that will put you up the creek with no paddle.

 

No. I took the "How to clean your Mikuni carbs" writeup from the XJCD and added pictures.