Hope you guess my name ( new member, sort of )

[5twins]

No, that's a float or float needle and seat issue. The floats may have gone bad, filling with fuel and becoming "sinks", lol, or the float needles aren't sealing in the seats.

 

[John Regular]

Alrighty then, I got distracted by a crazy red head named Maxine and have been spending a little time getting to know her
She is going to need some work. Back to the carb guide! The next step is pulling the float bowel and removing the floats and

valve. The Guide and pic of a suzuki BS34 state that The BS34 float needle is retained by a screwed-down tab, however mine was not. It came out with the

float


Is this normal for a 1980 BS34? Do I maybe have the wrong seat? Does that needle look ok? I'm going to attempt to unscrew the seat but if it's stuckk I'm

going to wait for the JIS drivers that I ordered to get here. I'l test the floats tonight.

 

[5twins]

The float needle seat is retained by that little screwed down tab, not the float needle. It is as you found yours, and that all looks correct and original. The seat is just a press in fit into the bowl and has an o-ring around it to seal it into the hole. They can often be quite stuck and getting it out can damage it - unless you make up a simple "special tool". This is nothing more than an old shanked bolt with a slight taper ground on the shank end ......

You tap it into the seat and grab it with some vice grips. It allows you to rock the seat back and forth but more importantly, to twist it and break it free .....

And the best part is no damage is done to the seat.

 

[John Regular]

The float needle seat is retained by that little screwed down tab, not the float needle. It is as you found yours, and that all looks correct and original. The seat is just a press in fit into the bowl and has an o-ring around it to seal it into the hole. They can often be quite stuck and getting it out can damage it - unless you make up a simple "special tool". This is nothing more than an old shanked bolt with a slight taper ground on the shank end ......

View attachment 348278

View attachment 348279

You tap it into the seat and grab it with some vice grips. It allows you to rock the seat back and forth but more importantly, to twist it and break it free .....

View attachment 348280

View attachment 348281

View attachment 348282

And the best part is no damage is done to the seat.

Thanks, thsat's what I figured but wanted to be sure. So there is a typo in the guide that might confuse people who don't know any better, like me.
"The BS34 float needle is retained by a screwed-down tab" I tried to take a screen shot but can't find it, Ill try to make one of those special tools

 

[John Regular]

So it took a while to get the chokes unstuck, one is still a little sticky. I decided to make one of those tools to remove the float seat but smoothed it out a little too thin to fit tightly but I found another way, One of the seats just kind of fell out once I removed the keeper. I'm guessing that that's not good? Here's some pics Looks a little dirty to me. Everything else was all shiny and new so I was hoping I wouldn't have to mess with them too much but it will be good practice and I have 2 more sets to rebuild. I need to get a real parts cleaner, I've been using one for gun brass

 

[John Regular]

I decided to get started on the carbs again today . I figure after seeing how gummed up the choke and valve seat were that I would plan on doing a

complete tear down and cleaning Following the guide. With all the tips and tricks and little caveats of info it's nearly idiot proof. Nearly. I don't mean to

criticize the guide but myself and how I often miss the obvious. I was trying to remove the needle jet per the instructions. I knew you smack it out (gently)

from the bowl side through the venturi. I installed the main jet back on and found a piece of ABS plastic to make a drift punch out of and gently beat the

shit out of that circuit for hours. I only got it to move a coup;e of milometers. I tried heat, penetrating oil, prayer, nothing would budge it. I knew I had to be missing

something so went back to the search looking for an answer and every post seemed to mirror the guide instructions, Install the main jet hit it out from the

bottom and it will eventually come out. Then I found the phrasing that I needed with a little extra nugget of info. To remove the needle jet First remove the

slide assembly, the main jet then REMOVE THE WASHER that is under the main jet, re-install the main jet and gently TAP out the needle jet. Thanks Twins.

I learned that the washer, which is also brass and looks like part of the needle valve especially after hammering on it and fusing it together with said valve,

actually holds the needle valve in the carb body. Well I still managed to move it a little so how bad did I f@ck it up?

 

[5twins]

I think you'll be OK. If you deformed the washer from beating on it, "dished" it in towards the needle jet then I would recommend flipping it over when you reinstall it so the needle jet will get pulled in completely and seat into the carb body all the way.

Good thing you got it out, it looks nasty, lol. My buddy swore up and down to me that he cleaned and/or replaced all the parts in his BS34s. When I finally had a look at them, they were a mess, lol. He never pulled the needle jets out and they were even more gummed up than yours. And he had plastic floats set at the brass float spec.

Make sure you clean out all the little holes down the sides of the needle jets. Those are the air bleed holes and if plugged, there won't be enough air let in to mix with the fuel, resulting in rich running.

 

[John Regular]

I think you'll be OK. If you deformed the washer from beating on it, "dished" it in towards the needle jet then I would recommend flipping it over when you reinstall it so the needle jet will get pulled in completely and seat into the carb body all the way.

Good thing you got it out, it looks nasty, lol. My buddy swore up and down to me that he cleaned and/or replaced all the parts in his BS34s. When I finally had a look at them, they were a mess, lol. He never pulled the needle jets out and they were even more gummed up than yours. And he had plastic floats set at the brass float spec.

Make sure you clean out all the little holes down the sides of the needle jets. Those are the air bleed holes and if plugged, there won't be enough air let in to mix with the fuel, resulting in rich running.

I thought maybe I malformed the top of the needle jet and I did slightly mushroom the top of the main jet but I don't think it will effect anything. The rest of the carbs looked really clean and had new bits put in (from PO) I have another pair that He Cerakoted (the carb bodies) with new jets and pieces. I have another pair on a spare motor I picked up so 6 in total, I figure if I rebuild all of them then I should have a better understanding of Bs34s.

 

[5twins]

Even though many prefer the BS38s, the BS34 is a nice carb. It's lighter and more modern that the BS38, and once you "fix" the factory lean jetting, they're a really good carb. Speaking of which, even an all stock bike will be happier and run a little nicer if you go up one size on the mains (132.5 stock to a 135). The bs34 also has a removable air jet feeding the idle circuit you can change. This doesn't have as big an affect as changing the actual pilot jet does, so it can be used to "fine tune" the idle circuit. You can achieve richness levels in between pilot jet sizes by changing it. And the jet is nothing special, not an actual dedicated air jet, but rather just a small round main jet (as used in the BS38s), but in this case it flows air, not fuel.

 

[John Regular]

So I decided to get back to finishing the carbs today. After putting it off for 2 months I guess I felt inspired by some of the threads that I read, or maybe
motivated? Compelled is a better word, yeah that's what I was feeling.. I finally got some doctor ordered time off of work so figured I had better get moving.

I got everything all shiny and put back together, however, when I was installing the choke rod I realized that the ball and spring keeper were missing. No big

No big deal, probably the cat, I could still hook up fuel and see if it still leaked.. But while I was connecting them together I kept hearing a rattle inside so I

pulled the bowels and it was both of the pilot jet covers, plugs? They would not stay in and I was hoping that maybe they didn't really need them but I

soon found out that hey do so feeling defeated, I ordered parts and thought of what I could do next, I decided to install the exhaust that I bought last winter

and figure out mounts and such. The left side looked pretty cool and I thought that this might be the look I'll stick with. I had wanted to build a tracker of

sorts but it had already been started by the PO as a cafe racer and I just wanted to finish it. I could start a street tracker next time besides I don't want to put

Halfmile's pipes on a short squatty special. but those pipes look alright. As fate would have it, the right side would

prove to much more challenging. Although the left cone had plenty of clearance, the right ran right into the shock mount. No matter how I tried to adjust it as soon as i tightened the exhaust nuts it went right back. Furthermore it was in the path of

the brake pedal as well. With the slight up-sweep and the cones position I might have had a hard time fitting rear sets as well as well. I thought maybe I

could bend them just a tiny bit and even found a thread where the same thing had happened to another member who had bought aftermarket pipes. The

advice from the guru was NO do not bend them yourself as the chrome will crack, take it to a muffler shop. So, I pondered, WTF to do now?

I could run open exhaust, find tiny cans, use them on something else? They would look dumb on my chopper..... Then It hit me, You know, It was like a

blinding realization, like pure truth. The choppers original head pipes might work! They are from a 77 but I didn't think that they were up-swept and might

even miss that shock mount. Well I found them, they were angled but were much shorter and still needed to be bent a little. They fit real tight against the crank case and made contact on the right side but were kind of beat up anyway so I was like F**k it! I heated the

bend with a propane weed burner and stuck the safety rod from my harbor freight lift in the tube ( fit perfect) and pulled ever so softly until I thought it

might have bent. I then bolted it back onto the exhuast port stuck a 1/2 " piece of plywood between the crank case and the pipe, tightened the nuts, and let it cool in that position. It worked I'm gonna call that a win. So what do you think?
I'm calling it a "ScramFatBrat"

 

[John Regular]

So I got the rest of my carb pieces yesterday, installed them and buttoned everything up. I hung my chopper tank up as a remote reservoir, Hooked up the fuel line and turned the petcock on. A few seconds later gas comes gushing out of the right

carb worse than before I cleaned them. I figured something like this would happen so I drained them, pulled the bowel and

the the float. I could feel the gas sloshing around in the float and noticed, for the first time. that that float had dents and solder all over one end of it. How did I miss that? I was so fixed on the seat and the passage ways that I didn't really even think

about the floats. Luckily I have 3 sets of BS34s so I cannibalized one from another carb and replaced the sink. I buttoned everything up again, turned on the

fuel and this time the left starts gushing. It was just fine a minute ago. So I pulled the bowel and the first thing I check is the float, it's fine. I check everything

else including the float seat filter and it all looks good so I grab that spare carb and start comparing all the pieces. I noticed that the plunger on the float

needle that was in the problem carb worked but not as well as the one in the spare carb. Also the one in the spare appeared to be brand new so.....I swapped

it out with the other, installed, buttoned up, turned on gas and no more leaky. I let it sit overnight with the gas turned on and it was still holding tight when

I got up in the morning.

The reason I had the spare in the first place is because, as I have mentioned before, this was someone else's project that I acquired and It came with boxes

of extras including 2 extra BS34 carbs that were in pieces. He had gone through the trouble of cera coating them and I wondered why he didn't use them

then thought maybe he messed something up cerakoting them. After inspecting them this go round I now believe that these were the carbs he had

intended to use and I had assumed the ones that were installed on the bike were. They have new gaskets and shiny bits installed but were just in pieces in a

box. I plan on rebuilding the spare set once I get some more parts ( at least 1 float and one float valve) The third set I have are on a spare motor that I

picked up off CL. It's pretty dirty and the mixture valves still have the covers on them so it might be all original pieces. I will wait until I get a sonic cleaner

before tearing into those ones

I installed the carbs back on the bike and they are still looking good I still need to figure out

what I am going to do in the battery/electrics area, attach the seat and hook up the rear brake. I think I have enough done to try to

start it, I just have to check all my connections and revisit the starting procedure for that moto gadget knock off it has.

 

[5twins]

Are those 145 main jets I see in your last pic? If so, I think you're going to find them too rich. 137.5's are the biggest I've been able to use in BS34s so far.

 

[John Regular]

Are those 145 main jets I see in your last pic? If so, I think you're going to find them too rich. 137.5's are the biggest I've been able to use in BS34s so far.

Yeah they are, I have other ones (135? I think) I don’t remember the pilots but I can check when I get home. Good thing I have another pair, I can put smaller jets in and do the Pepsi Challenge to see which one works best, provided I can get it started

 

[5twins]

With those freer flowing mufflers and (I assume) pod filters, you'll need at least 137.5 mains, maybe even 140s, and one up on the pilots (42.5 stock to a 45). And if the pilot circuit still needs to be a bit richer, you can reduce the air jets one size (135 stock to a 132.5). But only riding the bike is going to tell you exactly what's needed. Yes, these bikes require re-jetting for mods, but not a radical change, only a few sizes from stock on the mains and usually only one on the pilots.

 

[John Regular]

I figured out why the PO didn't use the coated carbs does that look salvageable?

I have 1 more set and they don't look like they have ever been messed with so I would have to drill out the plugs myself without buggering them up,I read the tech thread, any more tips?

 

[GLJ]

I figured out why the PO didn't use the coated carbs does that look salvageable?

From what I can see in the pic the answer would be yes.
I would use heat and a ez-out.
@gggGary could prolly give you a good idea on better ways to do it.

 

[gggGary]

https://www.xs650.com/threads/what-have-you-done-to-your-xs-today.32082/post-888187

drill a hole slightly smaller than the OD of a T15 bit with 6 points of contact, Then tap in the bit, that bit doesn't expand the brass wedging it in ever tighter (near as much as an easy out). the hot tip.

Bonus points it's about impossible to bust off a T15 bit in a brass jet.

 

[John Regular]

https://www.xs650.com/threads/what-have-you-done-to-your-xs-today.32082/post-888187

drill a hole slightly smaller than the OD of a T15 bit with 6 points of contact, Then tap in the bit, that bit doesn't expand the brass wedging it in ever tighter (near as much as an easy out). the hot tip.
View attachment 353874C
Bonus points it's about impossible to bust off a T15 bit in a brass jet.

Challenge accepted.