Learning Curve #2 - The Carbs

[FJTillDeath]

Ah, much a heated discussion arises when someone mentiones the carbs, my questions are simple enough though...PS AndyB - your guide helps me understand my manual so much better!!!

Anyway. I attempted to sepaerate the carbs from one another. There are 2 mounting plates/ joining plates that each have 8 screws. In the maunal it mentions these will be very tight! They were. of the 16 I managed to remove 5. The other 11 heads are all stripped along with 2 broken skrewdrivers. I tried using a hammer to shock the skrews - only helped for 5 of them. I tried to use easy outs to remove the stripped skrews even after using penetrating oil and still managed to snap the easy out once. I asked around and a heat gun was mentioned as people often use loctite on the screws. somebody said that only an oxy acetylene torch would provide enough heat. The manual made mention of an impact driver, many warned me of this as it may damage the carbs so I did not try that

My question is. I bought the carbs rebuild kits from Randy, along with the oring and screw kit. Do any of the parts in his kit require the carbs to be seperated from one another? If so, how the flaming FUDGE must I remove the skrews??? Im fine with forever leaving them in if I dont have to seperate the carbs. I went to a good number of bike shops and oher places asking around what the best way to remove them would be and everybody has different options so I am a bit sceptical about taking them in to have the screws removed and pay an arm and a leg for it


Update though. I can and have seperated the tops of the carbs and the float bowl chambers. Also found a good amount of crud in the bottom of the float bowls there be the drain screw. Next project is to remove the floats and proceed from there. I cant help saying that I feel like a kid with a new toy when looking inside the carbs. Its really exciting and at the same time I dont want to stuff anything up

[FJTillDeath]

Oh and the float chamber gasket was very brittle and hard. I managed to peel it off, but there are still some smooth pieces of it stuck to the bowl.

Should I ignore it and just place the new gasket on, or what would the best way to remove the remaining pieces be? A file, razor blade edge, sandpaper?

[simi_ed]

Jessie, you're in dangerous territory here.  While those screws are difficult to remove, they MUST come out.  I really recommend that you stay away from an oxyacetylene torch.  That is way too hot for what you need to accomplish.  
Here's what I would do with stuck screws:  make a solution of 50-50 acetone and ATF (transmission oil).  Apply to the screws, around the heads.  Wait at least 24 hours, then try to loosen with a proper fitting screwdriver, which should be a #3 Phillips, IIRC.  If that fails, use an impact driver.  I would put the carb bank onto a block of wood to make them more stable, and to protect the diaphram mounting surface.  If that fails, use a drill bit slightly larger than the diameter of the screw body.  Drill the head CAREFULLY, until the head separates from the body.  Repeat as needed on the others.  When you have the bodies separated from each other, resume trying to get the screws out.  Put more of the 50-50 mix on the screws, and allow to soak again. After 24 hours, use a locking type of pliers (Vise-Grip type) to grab the exposed threads and unscrew from the body.  

When you are removing the floats, BE CAREFUL.  Otherwise, you'll break off a mounting post and then you will need a replacement body, or have to figure out a repair.  Either option is not good!

You need to change o-rings between the carb bodies that allow fuel to flow between 1-2 and 3-4.  Otherwise, you will still have fuel leaks after you're done.  No fun!  

Good luck!

[simi_ed]

Razor blade, carefully scrape the bits of gasket off.  Otherwise, it will leak from there as well.

[FJTillDeath]

make a solution of 50-50 acetone and ATF (transmission oil).  Apply to the screws, around the heads.  Wait at least 24 hours, then try to loosen with a proper fitting screwdriver, which should be a #3 Phillips, Since I have already stripped the heads, I think Drilling is the only option  

If that fails, use a drill bit slightly larger than the diameter of the screw body.  Drill the head CAREFULLY, until the head separates from the body.  Repeat as needed on the others.  When you have the bodies separated from each other, resume trying to get the screws out.  Put more of the 50-50 mix on the screws, and allow to soak again. After 24 hours, use a locking type of pliers (Vise-Grip type) to grab the exposed threads and unscrew from the body.  

When you are removing the floats, BE CAREFUL.  Otherwise, you'll break off a mounting post and then you will need a replacement body, or have to figure out a repair.  Either option is not good! I will definitely be careful here

You need to change o-rings between the carb bodies that allow fuel to flow between 1-2 and 3-4.  Otherwise, you will still have fuel leaks after you're done.  No fun! Ah flip, so much for the easy way out  

Good luck!

Thanks for the advice, this is definitely going to be a nightmare

[FJTillDeath]

Okay just to confirm. Is acetone Nail Varnish remover? I went to my local hardware store and the guy said they didnt have acetone and the only place to get such a thing was at some industrial place or to just get the nail varnish remover.

Since its not exactly 100 percent acetone what ratio would I use to mix. I would like to try this when I get home today so that tomorrow I can get the carbs apart and back in asap

[simi_ed]

Well, that's interesting ...  Acetone is rather common in the USA, surprising that a hardware store does not have it.  I don't really know about nail polish remover, but it appears that it is essentially the same stuff.  
The ratio is not really critical, the acetone is the solvent to allow the oil to penetrate better.  It then evaporates, leaving the oil to loosen the rust holding the offending bolt/screw.  And to further specify, ATF is automatic transmission oil, not gear oil for a manual transmission.  
Don't buy a large quantity of either for this project.  If you can get 1/2 liter of each, that's sufficient.  Also, you will something to mix this in, and then store the unused liquid.  If you plan on saving for later, it needs to be tightly sealed.

[FJTillDeath]

As far as I can tell there is no rust, atleast not on the screws I managed to remove. I will give it a try though. The skrews are just really small and I am wondering how effective gripping them with the vicegrips will be,

The last thing I am having trouble figuring out is how the head will be seperated from the thread while still leaving enough for the vice grips to grab ahold of.

If worst comes to worst nand none of this works, is it possible to drill the skrews out and then retap the threads? I really dont want it to come to that, but I need to know there is sort of a last resort...

[simi_ed]

Trust me. if these screws are not turning, they're rusted in place.  The rust may be clear or white colored, but they are oxidized in place.  The oil/acetone mix will allow you to get them loose.  If the screws are too short to attack with Vise Grips, get a smaller pair.  The next plan would be to slot the screw body with a Dremel disc cutter, and then use a flat blade screwdriver to get them out.

Drill out?  Yes, it's possible.  If that becomes necessary, you will need a variety of left handed drill bits, a sharp center punch and LOTS of patience.  Centerpuch DEAD-CENTER, then drill EXACTLY down THE CENTER of the screw body with the smallest drill bit you have.  Then drill again, with the next larger bit EXACTLY down THE CENTER of the screw.  Eventually, the drill bit will exert enough torque in the loosen direction to unthread the screw out of position.
Re-tapping the carb bodies?  Not really practical, but theoretically possible.  Better to not get to that point ...

[andyb]

Oxidization in any form on a metal = rust.  Usually that means iron oxide, with is the familar reddish color, but aluminum will do it as well (arguably it's galvanic corrosion, blah blah blah insert metallurgy rant here).

A propane torch is plenty of heat for this sort of thing, but don't go there.  Porous metal + open flame.... you know what's going to happen.  Aluminum is relatively easy to melt, while I'm at it, and I know that you can melt aluminum washers with propane... so don't go there.

Vicegrips imo are a last resort tool.  Seems like every time I get to that point, stuff gets broken and I have a bad day.

Left handed drills are a good idea, but don't bother with a drill at all unless you've got it in a press and have things securely locked in a vise.

Acetone is nailpolish remover.  Nailpolish remover isn't always acetone.  You'll see some marked as being gentle on skin or whatever, and that's not what you want.  Just read the label and you'll find the right stuff most likely.

ATF + acetone is a lovely penetrant, though the last time I used it, things ended up in a suspension rather than mixed as clearly as I wanted.  Using a spraybottle with a misting nozzle on it helped to mix them, and I just liberally blasted away.  As the acetone evaporates, the ATF is sucked into the spaces where it was, and seeing as ATF is just oil with bucketloads of detergents in it, it worked. 

If the heads are still there but chewed up badly, I'd try getting a penetrating oil on them for a few days, and then a dremel/die grinder to cut slots in the screw heads, followed by a flat screwdriver/impact driver.  Drilling is a last resort, and requires quite a bit of care to not screw (see what I did there) things up worse than they already are.

[soundmindryan]

Okay just to confirm. Is acetone Nail Varnish remover? I went to my local hardware store and the guy said they didnt have acetone and the only place to get such a thing was at some industrial place or to just get the nail varnish remover.

Since its not exactly 100 percent acetone what ratio would I use to mix. I would like to try this when I get home today so that tomorrow I can get the carbs apart and back in asap

Yes, there is acetone in nail polish remover, but a very small concentration. It's mostly water and fragrance, if there's any acetone in it. Most of it these days is ethyl acetate.
Go to the hardware store (or Home Depot/Lowe's/WalMart) in the plumbing section and get this:

It's about a 50/50 mix of MEK and Acetone.
KEEP IT AWAY FROM ALL YOUR FAIRINGS! It will eat it.
That leads me to a Fairing repair thread that I'll write.
Kookaloo!
Ryan

[FJTillDeath]

Cool now I feel a lot better and know what to do. I will see  if I can get any proper acetone, otherwise I will use the nail polish remover

Sadly in South Africa there is no such thing as walmarts/ lowes/ etc, but I will have a look. I will first try using a dremel to cut a slot in the head and if that doesnt work I will resort to drilling...

With regards to the impact driver - is it safe to use on the carbs? All the places I asked said it may crack something and that would be a nightmare... So in place of an impact driver would using a normal hammer(or is a rubber hammer better?) substitute in aid with the penetrant(I cant stop giggling at that stuff)

Well I'll be gone for a day or 2, so hopefully when I am back I will have the forks back on and my carbs seperated. And if I manage to stuff up my carbs, I can always make another loan to buy a new shiny set from Randy ...I hate DEBT

[soundmindryan]

With regards to the impact driver - is it safe to use on the carbs? All the places I asked said it may crack something and that would be a nightmare... So in place of an impact driver would using a normal hammer(or is a rubber hammer better?) substitute in aid with the penetrant(I cant stop giggling at that stuff)

We

Is this the impact driver you all are referring to? I think this kind will provide gentler results than an air or electric powered impact gun.

Just sayin...

[andyb]

Yes, there is acetone in nail polish remover, but a very small concentration. It's mostly water and fragrance, if there's any acetone in it. Most of it these days is ethyl acetate.

Read the labels.  I have a bottle of "Studio Tools professional strength nail polish remover" on my desk, and it's straight acetone with a tiny bit of denatonium benzoate added (to make it less drinkable, apparently...).

If you're using an impact (yes, a hand type usually is what I use on anything that's not huge), you have to ensure that you're supporting whatever you're hitting, or you can and will break tabs and corners and such off.  Just use common sense and you'll be fine.

[SlowOldGuy]

Go get a small punch or a nail driver and grind it to a sharp point.  Hammer this into the side of the head of the stuck screw in the direction such that you're unscrewing it (i.e counterclockwise).  The point should be sharp enough to dig itself into the screw head and with a few hits fromt he hammer the screws should break loose.  I've used this method on probably 30 carb sets.  Works for me everytime. 

DavidR.