Fuged mix screw. Might need carb bodies

joebgd

XS650 Junkie
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I have a seized air mix screw, bs34s, I got a screw extractor w reverse bits and it's just crumbling and flaking n I'm so close to the end I'm afraid that it's goner. Idk wtd. I'm gonna look on eBay for bs34s.
Edit- Dang, I put so much work into cleaning electric connections and totally rebuilt carbs then have the mix screw buggerd in pieces. I should have worked on the screw 1st. I'm gonna try and get the pieces out tomorrow but I don't see how I can and not hit the carb. Ugh
 
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I'm not a fan of those VM34 carbs. I can sell you a set that would be just for parts. I dunno, $25 plus shipping sound good? I mean these carbs were on a bike that sat outside for a very long time.
 
I've had to drill those out, go slow and carefully and you can drill right to the threads and then pick out the remnants.
 
Thanks. Appreciate the help. I hope I can make it happen w what I have. I'll know tomorrow when I get back to it.
Jay, I might take u up on that, can u send me a pic? I just wanna be sure were talking about the same carb. I'll pm you. There stock on 1980 and up bikes.
They are cv I think, I see you wrote vm, I'm not sure if cv and vm are just a different way of saying the same thing.
Pm sent.
 
Holy cow, I got it!!!
. I thought I ordered 2 new mix screws but apparently I only ordered 1 and the pin on the end looks a bit thinner than stock. I'm not worried about it. It will be fine just maybe be turned in a bit more.
 
Dang, I thought I had it. Turns out I must have hit the threads. I thought I had it in but on ride it came out and I couldn't get it to go back in. The last test ride I actually lost the screw, must have popped out on the road. Ughh
 
I have a lead on a set of carbs that I can go through swap parts.
I ran it with no mix screw in one carb to sort out and confirm my battery is shot. The carb was leaking like crazy. The day I lost the mix screw I didn't leak at all. Can not having a mix screw cause allot of gas to fill the carb or I have a problem w the float. I'm going to take them off and wait for some parts. I ordered 2 Yamaha mix screws from partzilla. I'll take a look inside when I get them off. I did have to resolder a float on, It was strong I can't imagine it came off but something is going on in there.
 
Okay I am back from my trip to the country home in upstate N.Y.
I got the nos mix screw from partzilla to thread in no problem. Shwew I am thrilled about that. I got a set of carbs with the newer bowls and probably newer floats. The bodies are actually worse than mine tho. The float in my right carb is mangled so I'll swap that out and the bowls. I'm going to start her up later and go for a.little ride. I think I lost that one mix screw because I had it turned out like 3 and a half. I also put anti siez on the threads which I did again and have it on both mix screws now to avoid furthers sticking. It's a grease type substance used to.splice copper and aluminum. It helps keep the different elements from seizing together.
 
Be aware that if you switch to the newer type plastic floats, they have a different setting spec (22mm) than your original brass ones (27mm).
 
This time I'm starting w 2 turns out because I am up on the both the pilot and main jets. I am going to go 2 1/4 on the right. I like the idea of a fuz more fuel on the hotter running cylinder. I also have a very very slight shim under the emulsion needle on the right carb. The emulsion tube and needles are stock.
 
Thanks 5, for that, got it 22mm on plastic. Also the tip on the nos mix screw. Good call on that. Just because it's not listed as a part for my bike doesn't mean it's not available and used and listed under other bikes and bs34 years.
 
IMG_20200722_170955.jpg
Any ideas on how to get that drain screw out without ruining anything? On the other carb it came out fairly easy. Nothing got stripped, this one is stubborn and I want to be able to check fuel heights. I have penetrating oil on it now, what about heat?
It is already starting to strip the screwdriver slot.
 
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Edit- The head stripped right off that one. If I can get it out with a reverse bit and screw extractor where can I get a screw like that?
 
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Got the carbs sorted out nice. Finally got it where I want it. Maybe a little tweaking as I go on a longer ride.
Put the Kawasaki clutch lever, I didn't go for a long ride but it seems it might give a fuz more separation as well as a sturdy lever.
 
She is running like she wants to. You know so good you just don't wanna stop. Carbs sorted new battery, I don't have to worry about it stalling if it idles at a long light due to a beat battery and she sounds good exhaust doesn't sound all frighteningly lean, sounds nice and content. :)
 
Everything is running good since carbs sorted, new battery, I think there is a little stumble between 2-3k rpm, need to ride more and get a feel for it, in general tho running awesome, I think I'm even getting better gas mileage, I'm not sure because I've been taking the parkway more on my usual commute. I can use the e start no problem, doesn't stall after idling a bit.
I've been using Stabil 360° protection, half ounce a tank. The Kawasaki clutch perch definitely lets off smoother, there is 0 bumping when taking off in 1st, I have it set just right, there is 0 free play when cold once she warms up the lever has free play.
So I'm happy with the yuasa lead acid, conventional, battery, the carbs and the clutch lever.

Edit- just thought of something, I started using regular gas, when I started getting better milage.
I did allot all at once when I noticed better mileage so idk if it is any one thing, or may even be I'm doing more highway driveing.
 
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I am having trouble w idle, sitting here now thinking, I think its to rich at idol. It doesn't really hold an idol less than 14k and is much better at 15. When I idle at a light if I don't feather the throttle and let it idle for a min or less, when I go to take off it kills the engine. I had the plugs gapped at max even a bit over. I closed the gap on the plugs and I'm going to go in a half turn on each mix screw. I think they are both at like 2 1/4 out right now. I'll post after the next adjustment.
 
I would turn the fuel screws 3 turns out. I have tried so many ways to run these bs34s and even go up sizes on pilots have always found the sweet spot is around the 3 turns. Maybe a touch less or a touch more but try 3 turns. However if the screws are not stock and the end is smaller like you say then it will need to be turned in. I have one set like that I think I got from mikes and I have to run them at 1 turn out. Also you say your spark plugs are maxed out to what? I have found mine always ran best Gapped at 0.032 inches.
 
I had the plug gap at .89mm the high side of recommendation is .8mm , I closed it up a little, I forget right now to what but it was under the .8 .
In inches .8 is prob ab .032
The high side recommendations in the manual are 8mm or .031"
 
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