First time carb teardown

[exzachtly1]

I continued to tear down #4 to see what I was getting into, and the pilot jet is all sorts of mangled. I haven't touched this yet - PO did a real job on it. I don't have a screwdriver that fits this channel so I'm probably gonna have to go buy something before I even try to remove it.



I'm worried that this means I may need to buy new jets. Are the kits on Z1 worth the money? Guess my bike is going to be out of commission longer than I thought

[mike10]

Screw drivers

Buy some good quality screw drivers if you don't have them. It makes a difference they fit better and will get a screw out where the cheap ones won't. Penetrating oil, Tap on it with something metal that will fit down in there but not too hard and not your screw driver, could mess up the tip or the handle not ment for beating. Give the oil time to work. Take the screw driver and work it back and forth. Most screws can't much of this and will give up and come out.

[exzachtly1]

Buy some good quality screw drivers if you don't have them. It makes a difference they fit better and will get a screw out where the cheap ones won't. Penetrating oil, Tap on it with something metal that will fit down in there but not too hard and not your screw driver, could mess up the tip or the handle not ment for beating. Give the oil time to work. Take the screw driver and work it back and forth. Most screws can't much of this and will give up and come out.

Thanks, I will give this a try. Soaking them in PB blaster now. Another problem area is the pilot jets - all of them are pretty mangled already, previous owner stripped all 4 of em. There's almost nothing to bite into even if I did have the world's best screwdriver. I have only gotten one out so far.

Once I manage to get these bastards out and am ready to rebuild, it doesn't look like Z1 sells the jets individually; am I stuck buying the rebuild kits (25$ / ea.) for each carb if I want to replace the pilot screws and pilot jets?

[exzachtly1]

This may sound like a dumb question, but is it critical to the cleaning process to get these particular parts out? I'm just wondering if the benefit of getting them out is worth the risk of potentially having to ruin them. These things seem REALLY stuck.

Walking away for now I guess before I get too mad

[7981GS]

In Ed's tutorial, it even tells you how the file down the screwdrivers for a perfect fit.
Follow his directions and use a lot of down force on what you are trying to unscrew with plenty of penetrant and you should be good.

Eric

[exzachtly1]

In Ed's tutorial, it even tells you how the file down the screwdrivers for a perfect fit.
Follow his directions and use a lot of down force on what you are trying to unscrew with plenty of penetrant and you should be good.

Eric

Yeah, I saw that he had what looked like a fatter, filed down screwdriver. The problem is that wouldn't even help me... the 3 remaining pilot jets are already BADLY stripped from the PO. In fact, they're so bad that one of them appears to not have anything left to bite into. I am fearing that I will have to use desperate measures to get these out, like a screw extractor kit (destroying them) and replace with new.

The pilot screws are a little less worrisome but still giving me trouble.

EDIT: here are pics of the 3 stripped jets:







The last one was the worst one, and the only one i attempted to loosen. As you can see, now there is NOTHING left on it. It's completely flat.

Here are the 2 remaining pilot screws. First is near completely stripped. This one was definitely my fault, I got over-confident... but I'm hoping i can still work with it:

[mike10]

Ask Around

Someone may have the jets you need many guys fool with carbs around here. Hate to waste money on kits. If you have to replace them.

[exzachtly1]

In Ed's tutorial, it even tells you how the file down the screwdrivers for a perfect fit.
Follow his directions and use a lot of down force on what you are trying to unscrew with plenty of penetrant and you should be good.

Eric

Actually, I don't see an explanation of how to do the filing... what is the appropriate tool to use to file down a screwdriver that way? I'm assuming that you generally cannot find screwdrivers already made at that width that will fit inside the channels that these screws are in? Would you use a manual file like this to do it?

I have a screwdriver that is very close to working for the mixture screws, but nothing close for the pilot jets.

[GateKeeper]

that file can be used, or use can ue a bench grinder, or a dremel, or anything that will file the sides of the screwdriver down enough to fit into the hole and turn without hitting the sides....

the other important part is to get a screwdriver that fits the slot of the screw/jet properly and fully, as this will prevent from damaging the walls of the screw/jet and allow for easier removal

.

[exzachtly1]

Cool. I'm hitting a bit of a wall because I don't have some of these essential tools... no heat gun, no vice grips to hold the carb body for me while I work, no dremel / files, no extra screwdrivers to file down (I have a couple of normal screwdrivers, but none the appropriate size. All of the others are bits that go into a ratcheting driver, which have been perfect up until now).

Starting to feel the pain of how much money I'm probably gonna have to spend to do this right. I'm definitely going to have to buy new float bowl gaskets, pilot jets, and maybe even a couple of fuel mixture screws. I'm worried that one of them is too stripped to continue using after I get it out.

Everything was coming apart so easily up to these few final screws... such a bummer

[exzachtly1]

Well I've just ordered new pilot jets, plugs, and float bowl gaskets (the old ones were pretty shot, one fell apart). Bikebandit had a pack of 4 pilot jets for $12 (Mikuni 42.5).

So... at least I will have everything ready when (if) I can get the stripped jets out.

In the meantime I will continue to accept any advice for dealing with these things. I think one of the screwdrivers I have is the perfect size for the mixture screws, but wont fit into the channel. I put together a shopping list...

bench vice clamp (to hold the carb body)
left hand drill bit (please advise if this is the best method for the stripped jets)
screwdrivers - .0385" for mixture screw, .0350" for jets (or just use existing screwdriver)
file
torch

[exzachtly1]

Question - assuming I have trouble with the mixture screws and (worst case) I need to replace one or two of them, where can I find a replacement? I haven't been able to spot them anywhere online. Closest thing was on Z1:

http://www.z1enterprises.com/ItemDetails.aspx?itemDescription=Fuel+Mixture+Screw+%28BS+Series%29+GS750+GS850+GS1000&item=KL18-2645

But that says it's for the BS34. I'm confused though - Ed's tutorial says that GS550, 650, 750, and 850 share the BS32? Will this part fit my GS650? It sure looks like it will and I just want to be prepared in case I have to replace any of these.

[exzachtly1]

I did some searching on the forums and I think I might end up trying Steve's suggestion of re-slotting the mixture screws with a hack saw or dremel. I am probably going to have to ez out or left-hand drill the pilot jets.

Do you guys think that soaking the carbs in the carb dip before doing this stuff will help loosen the threads on these remaining screws? I understand that it will probably eat the rubber gasket on the mixture screw - will that be a problem? I have the replacements from cycleorings.com already.

Picked up a propane torch for heating, some new screwdrivers that should fit much better, and an ez out bit today. I may be posting in the "parts wanted" section soon if things don't go my way

[GateKeeper]

Always think positive.....

[exzachtly1]

VICTORY!
...almost

I got the 3 pilot jets out. Here's what worked for me - read this a couple of times and decided to give it a whirl since I remembered that I actually did have a Torx lying around...

T8 torx, set it in the center of the jet head with a few firm whacks with a rubber mallet. This gave a really good bite and i was able to press down with all my strength on the bench and turn the carb body with my other hand. POP! Came right out. No heat required.

Now I still have to deal with the 2 damaged mixture screws. I plan to tackle that later with the slot method, copious amounts of heat and PB blaster. My only concern - will the heat melt the rubber o-ring inside? I have replacements BUT i dont want to gunk things up in there with melted rubber.