VM26 pilot screws broken

[KEITH KRAUSE]

Hey Bruce, here you go buddy

Read this! --> http://www.thegsresources.com/_forum...ic.php?t=38306

Mark, I just checked out your topic about removing broken pilot screw tips and I appreciate the effort and it looks like it could work.
But in your pic's those 4 screws aren't broken, and what you removed was really brass plugs installed by the factory.
From my experience, some '79 models received these leaner carbs. Had to be for smog reasons. I don't know what the manufacturing cut-off date was that the change took place. I stopped by Mikuni Corp. here in town and the representative couldn't answer that question but one of his technicians verified what I'm saying. Bikes with the leaner carbs were de-tuned slightly to allow for this. I made a topic about the two kinds of carbs a long time ago.
I've been through a lot of VM carbs and the only 2 sets I found modified like this were both off '79 1000's according to the salvage yard. I can't say they're rare, but they're not nearly as common as the "standard" carbs.
If you use a set of these leaner carbs on a bike that came with the "standard" carbs, you'll have lots of trouble if you don't notice the difference.
If you do remove the plugs, the "blunt tipped" screws won't properly regulate the second passage for the mixture. The bike will run rich. Or at least a stock bike will run rich. You have to find the sharp tipped screws.
I first ran across this years ago while rebuilding some carbs. I could see/feel the plugs but wondered why they weren't that sharp. Removing the screws, I could see they were machined blunt and in fact were just "dummy" screws and I then realized what I thought were broken tips were really brass plugs. This was obviously a way for Suzuki to meet changing requirements and to help stop tampering.
Your topic is still appreciated but I wanted to let others know how easy it is too mistake the plugs for broken screw tips. I don't know how easily your tip removing idea will work on a smaller, sharp tip of a broken screw, but it might. The blunter plug would be a little easier to hit squarely and not damage the hole.
PS: I guess I get kind of burned out making longer replies and trying to cover every possible base. That's why I haven't mentioned these carbs for quite awhile. If someone was to bring them up, as you did, then I speak up. Perhaps I should have posted this at your tip removing topic but I don't like to "hammer" other peoples posts that are meant to help others. Maybe I should have so people can fully inspect what they have before messing with their carbs but I won't bother to type all this again. If you think this should be added to your topic so others have more info, then I'll leave that to you to add it.
Good of you to make that topic Mark. I wish I could post pic's with my messages like that.

[Hoomgar]

I know what your talking about Keith. I don't think that is the case here though. Let me explain why I don't think so and if there is still myth in it I want to know so can pull my tip thread.

1. These carbs are the stock carbs of a 1978 GS1000C made in August of 1977 from what I understand. The VIN reveals it was one of the first few hundred made. The bike was one owner and according to the original owner all that was done to this bike was cosmetic and pipe and pods. He removed the grab handle from under the seat and the one on the seat to install the rack. He put a kerker header on it and removed the air box to install K&N pods. The carbs on it are the carbs that came on it when the bike was new in my understanding and I have no reason to think otherwise. If this is true then it rules out the scenerio you mention. But if they were replaced with a later model set of carbs, how can I tell? Outside of the plugs you mention?

2. Maybe you can't see it in the pics but the tips I removed are not all the same length and the bottoms are uneven. The tips of the screws are mangled and bent where the tips broke off from what it looks like to me. I can take some better pics if that helps? If you had them in your hand you could see what I mean. Two of them fell right out as I pulled the screws out. The one tip was still attached but it popped right off when I pushed on it because it looked cracked and mangled and was leaning to the side. Maybe it was just stuck to the pin with goo or something? It?s the one that is in the middle of the 3 screws together on the left in the first picture.

Is there any other way to tell? If there is a chance I am wrong about this I want to know it so I can both make sure I redo it right and to remove the tip thread.

Lay it on me dad

I wish I could post pic's with my messages like that.

You can, you just need to take the time to take me up on my offer to teach you

[KEITH KRAUSE]

First of all Mark, I don't think you should remove your topic about broken screw tip removal. It could help someone who really does have that problem. I do think now that what I mentioned about the leaner carbs should be posted there and people can just inspect and make up their own mind what they have. Your topic is about removing broken tips, but people should not automatically see a "tip" plugging the hole and assume it's really a broken screw tip.
To me, the leaner/modified carbs are obvious after inspection. The plugs do have kind of a "mangled" look as you say. But the end of the blunt screws used in these carbs is machined flat. If you took a "broken tip" and tried to match it to the end of the screw, it wouldn't match. The broken screws wouldn't look like that on the end. I can tell in your second pic' that there's a plug in there, not the end of a sharp tipped screw. Like I said, I've seen all these plugs/modified screws you're showing, right in my own hands.
And I read what you believe is the bikes history, but I don't believe the carbs are the original ones.

[renobruce]

Thanks for your response, Keith. IF I or Hoomgar DO have the carbs with the plugs in them, are they otherwise the same as regular VM26's? Is there just no adjustment for the pilot circuit? The screws are "dummies"?

[KEITH KRAUSE]

Thanks for your response, Keith. IF I or Hoomgar DO have the carbs with the plugs in them, are they otherwise the same as regular VM26's? Is there just no adjustment for the pilot circuit? The screws are "dummies"?

Yes, they are the same otherwise.
If your carbs have the blunt dummy screws and plugs, there's no fine tuning for the pilot circuit. You would have only the one open passage to the carb throat, regulated by the pilot jet itself.
I can't tell without seeing your carbs, but if you do have the leaner/plugged carbs, you could possibly remove the plugs and get some regular sharp tipped pilot fuel screws to achieve fine tuning for the pilot circuit.
To me, the dummy screws are obvious. Their end is blunt and machined flat, not twisted or broken shaped. If what you have was really broken screws, the broken tips, once removed, would match perfectly to the ends of the screws.

[Hoomgar]

OK that makes sense Keith. So the question then is since I removed the plugs, can I put regular pointed pilot fuel screws in there now and use these carbs? I'd like to if I can. They should be the same as my other carbs at this point now right?

Also Keith, if you would be so kind, please post in my tip thread about this and explain it the way you know it. I will then reference it from my first post so that new readers can see it and make the determination before modifying their carburetors.

Thx

[KEITH KRAUSE]

I can't be certain that the holes haven't been enlarged or damaged by the plugging procedure, and the couple of carbs I ran across that were plugged I just passed them up. So I've never tried it. I'm not saying these carbs won't work if you install sharp tipped screws, I'm saying they could be damaged and cause problems. You may think that if the holes really WERE enlarged that turning the screws in just a bit more would compensate for that, but I hate expereiments.
As I've found out before, you're going to do what you want and I try to understand that. You're trying to learn, and I'm just trying to give advice.
As for posting the extra info at the other topic, if you can, tell me how to without me re-typing and I'll try. I don't know how to post links or whatever you call it. If it can be explained easy enough (click this, click that) I'd like to learn.
By the way, at E-bay right now, a guy is selling what he says is a '77 GS1000/GS1000E owners manual. It looks like a '78 to me. Couldn't be much difference. I don't have the item # because I just thought of it, but just type in "Suzuki GS1000" and it's in there. I think there's about 2 days to go and no bids yet when I saw it.

[Billy Ricks]

Keith,

I know what you mean about the longer replies. I've copied some of my longer tips into a Word document so I can just go to it and paste the info into the forum. Saves alot of effort.

[KEITH KRAUSE]

Keith,

I know what you mean about the longer replies. I've copied some of my longer tips into a Word document so I can just go to it and paste the info into the forum. Saves alot of effort.

Sounds like a good idea. I have thought about saving info.
Of course, I don't know how to "copy into word document" or paste.

[Billy Ricks]

Sounds like a good idea. I have thought about saving info.
Of course, I don't know how to "copy into word document" or paste.

If you want to search some of your old tips then paste them into a Word or other document just highlight what you want to copy just as if you were highlighting something to quote here. Then right click with your mouse while keeping the cursor over the highlighted area. You'll get a box with a few options, select copy. Then minimize the screen you're copying from and have a blank Word document waiting to paste to. When you have the indent set on the Word page where you want it right click again and select paste. The copied dialogue should appear on the Word document.

[Anonymous]

Mr Krause, I work on Mikuni round slide carbs and can't recall having come across the "leaner" GS carbs you speak of. About 90 percent of my work is with Kawasaki VM series so this isn't really unusual I guess. In any case, you say the the pilot fuel mixture screw is not present and a screw in plug is in its place as I understand your explanation. Is there an air screw up on the side?

As far as the broken tips from the pilot fuel mixture screws being tightened too much, these are very difficult to remove without opening up the hole they seat in. I can remove some but not all without opening up the hole... I use a letter series drill bit to gently drill the end of the tip to loosen it and then try and press it out from the venturi side with a hooked dental pick with a broken off tip (blunt) to pop it back through. This works some of the time but many times it will not. You can drill through but even a very thin lettered type drill bit will slide off the needle tip and can open up th hole some.

I have found that one hole damaged/opened won't make a great deal of difference... some instability in idle... maybe 25 rpm will result and this is hardly noticeable. More than one hole opened up on a set and the idle variation becomes annoying as the small air leak causes a minor lean condition... two damaged holes can make the idle vary 100 rpm and this is annoying. More than two and the assembly might be considered unusable.

[xifer]

GS1000 MANUAL

By the way, at E-bay right now, a guy is selling what he says is a '77 GS1000/GS1000E owners manual. It looks like a '78 to me. Couldn't be much difference. I don't have the item # because I just thought of it, but just type in "Suzuki GS1000" and it's in there. I think there's about 2 days to go and no bids yet when I saw it.

Says 'From 77' on the front - it's 2.50 now with 30 minutes to go -
it is exactly the same manual as I have and while maybe not
perfect it covers everything as far as I can tell.

[Hoomgar]

Re: GS1000 MANUAL

By the way, at E-bay right now, a guy is selling what he says is a '77 GS1000/GS1000E owners manual. It looks like a '78 to me. Couldn't be much difference. I don't have the item # because I just thought of it, but just type in "Suzuki GS1000" and it's in there. I think there's about 2 days to go and no bids yet when I saw it.

Says 'From 77' on the front - it's 2.50 now with 30 minutes to go -
it is exactly the same manual as I have and while maybe not
perfect it covers everything as far as I can tell.

I couldn't find it. Guess I missed it :?

[KEITH KRAUSE]

Mr Krause, I work on Mikuni round slide carbs and can't recall having come across the "leaner" GS carbs you speak of. About 90 percent of my work is with Kawasaki VM series so this isn't really unusual I guess. In any case, you say the the pilot fuel mixture screw is not present and a screw in plug is in its place as I understand your explanation. Is there an air screw up on the side?

Yes, there is an air screw on the side.
These carbs are leaner because a second passage to the carb throat, which is normally regulated by the sharp tipped pilot fuel screw, is plugged with a brass plug. The pilot fuel screw used in this carb is blunt and machined flat instead of sharp tipped. It's easy to see the blunt/flat screw isn't a broken/twisted screw. This "dummy" screw only serves to seal the carb and even if the brass plug is removed, its blunt tip couldn't regulate the hole correctly.
The brass plugs are easy to distinguish from actual broken pilot fuel screw tips, because you can see their tip is fairly blunt also, not nearly as sharp as the tip of a normal pilot fuel screw.

[Hoomgar]

Keith, here are some better pictures of the screws like I promised. This is not to say your not right about the plugged carbs. I have no doubt you know what your talking about there. Quite the opposite here, I want to make sure that I know if I do or don't have the carbs your talking about. I am very hopeful of course that I don't but I also really think they may not be. Please look at these pics and give me your determination based on these. If you look at them close, you will see what is making me doubt.

They are different lengths...

The ends are not machined smooth at all. Quite the opposite, they are all rough and uneven and sharp and torn looking...

They are bent and two of them have sharp shrapnel sticking up still...

One of the two with the sharpest edges sticking up came out with the tip still attached to it and didn't snap the rest of the way off until I pushed on it...

Please look close, if you look at these and still say you think these were factory plugged carbs then I am not using them. Otherwise, they and nice and clean right now

The pics:






What do you think?