Need some advice disassembling carbs.

Hello again, been awhile since I last posted here.

I'm currently trying to tear down my carbs for a complete rebuild, but i'm running into my usual problem of frozen bolts and screws. (This motorcycle is just one giant glob of rust, I am convinced.)

I was able to pop off every "cap" screw successfully with some PB blaster and some light tapping, but these 2 ended up stripping pretty badly. I stopped before it got worse to see if anyone had any good tricks to get them out.
https://i.imgur.com/uGg5170.jpeg


I also noticed while taking the carbs out, that on the bottom of the rack there appears to be a few holes, some have flathead screws in them and some dont. I am unsure of the function of these holes, but am I missing pieces here?





Heres just a few general pictures of the carbs, they're pretty darn dirty! I don't believe the original owner had ever once cleaned them. (And he owned the bike since 81)

 

with a good set of small vicegrips you can grab the hat screws and turn them out. always soak with pb, I use kroil best stuff I ever purchased at 14 $ a can . soak bottom of screw let pen oil soak in from bottom.

the carb bowls have a screw to drain fuel. when bowls are made thay have locations cast in both sides of the nipple so they can become carb 1 and 2 bowls or carb 3 and 4 bowls. (cost saving measure by hatachi/yamaha)

 

go slow and be patiant.
do not force anything.

buy a set of JIS screwdrivers to stop damaging screws.

 

For hat screws that wont come out....
1. Yep, try to grab with visegrips to loosen.
Or
2. Use a dremel and cut a new slot for Flathead screwdriver.

I use either method with success.

in the rare instance that a head twists off, just drill the shaft, clean the threads, and carry on

holes—The screws are your bowl-drain screws. The holes, once you clean the mud-wasp mud out, will be where the fuel drains out. You’ll get new ones with your complete deluxe rebuild kit from Len.
The “hole” on the other “leg” of the “Y” is just an unused bore. It could be drilled and tapped if need be. The bowl blank Could have been used for either side of the rack.
dfox

 

Thanks so much for the replies, a small pair of vice grips worked a charm.
I do own a few JIS screw drivers, but the PO had already begun stripping these 2 before I got a hold of them, so there wasnt much left to work with.

The flathead screws holding the rack all together are not budging at all though, so I am going to keep soaking them in PR blaster.


Good eye hogfiddles, there was en entire wasp nest in the center of this carb rack before I took it out. Some of that mud is still around!

 

Those are assembled with some type of locking compound at the factory , they are a real beast to remove. Recommended solutions:

a) JIS screwdriver only!
b) Give them a strong whack with a hammer before trying to loosen.
c) If screwdriver fails, then vice-grips.

 

Thanks for the tips, I have a couple of impact JIS screw drivers that will hopefully do the trick. Is it safe to hammer down on that rack? It wont break anything?

 

Yes, within reason.

See above!

 

Only if you hit it too hard

 

Well after a couple hours of double handing a screw driver, excalibur style, I got every single rack screw out except for....
one.
And shes a stubborn girl.



The other two that stripped were easily removed with a pair of vice grips, but I twisted away at this spiteful screw long enough to make me pop an ibuprofen for the pain in my wrists. The little washer underneath the screw is ever so slightly wider than the screw head, and its causing the vice grips to slip off every time. I'm gonna soak it in more PB blaster over night and come back tomorrow with a fresh mind, and fresh arms.


On the bright side, the rubber diaphragms in here look a lot nicer than I thought they would. No tears or holes anywhere on any of them.

 

Taking the night off might work. Also, since it's an end screw, you can always break out the other carbs out of the rack, and then twist (turn) that long lower bracket (just like it's a wrench, so counter-clockwise) and maybe break the seizure on the screw in that manner.

 

I thought about using the rack as a wrench too, I'll probably give that a go tomorrow. Was hoping to get the rack off before breaking the carbs up, but oh well.

On a side note, is there a particular reason these screws were assembled with a locking compound? Will I need to do something similar on the reassemble?

 

Probably to keep the screws from backing out....but to be honest, I don't know if they actually were assembled with locking fluid (or similar), but they are always unbelievably tight (it could be corrosion). If you do use a locking fluid upon re-assembly, then I would use a low-strength type, just to prevent this issue from occurring the next time.......

 

If nothing else works, use a dremel or a hacksaw and creative a good slot for a big flathead screwdriver.

I use blue loctite for reassembly

 

So today, with a fresh mind and an extra set of hands, I was able to muscle the darn thing out. Freedom at last!

On a side note, I went to check the air filter on my bike because I assumed it had to be really bad by now. Well, it would be bad I'd bet... if there was one.



Am I wrong in assumiong there is supposed to be a filter here? Im worried about how long the previous owner was running the bike without one. Would explain why the air-side of the carbs are so disgusting.

 

1. Yup...Should be one there
2. Yup....probably why

 

Any personal favorite on which filters to buy? I see there is a few brands that seem to be compatible.

 

Standard paper filter