Aw crap... NOW what did i do??

suiteo · Posted: October 8, 2009, 1:28 am Post subject: Aw crap... NOW what did i do??

Alright, so newbie first time working on stock carbs. Should have known this was going to happen. Managed to get everything apart and soda blast the carbs. Nice and clean, and then I realized, I forgot to remove the needle seats in both carbs. One popped out relatively easily with a tap from a small nut driver, but the other was a little more stubborn. I was tapping the needle seat out from the bottom of the carb, using a small nut driver with a square end. The end was apparently slightly smaller than the diameter of the bottom of the needle jet, and a few probably firmer than needed taps, and now I have a square indentation at the bottom of the needle jet. The stock slide needle goes through it ok, but the bottom of the needle jet is a little buggered up. Is this going to be an issue with reassembly and the carbs functioning properly? Of course, these are the ONLY parts I didn't order this week. I was hoping to reassemble and sync Saturday morning so I could go for a nice ride, but now I don't know if this is going to be an issue. Any thoughts or insight if this will be a problem? I'll try and post a pic tomorrow. Just freaking out tonight. Sorry for the long post.

Jay

despecial · Last edited by despecial on October 8, 2009, 3:49 am; edited 1 time in total

use a magnifying glass and check that none of the holes have deformed

and buy or make a set of brass drifts - useful not only for carb repairs

RandyRyder · Full Member Joined: Sep 27, 2009 Posts: 33

I believe I'd plan to reassemble on Saturday morning. If you get 'em both put together and mounted properly in that amount of time, you'll be doing real well. If you can ALSO get 'em synched, you're way ahead of the game, and if you get it all done so it all works properly in time to go for a ride before noon, then you'll know that God loves you.

Joseph · Full Member Joined: May 22, 2007 Posts: 767 Location: NY

I think you'll bee alrigh.

suiteo

Ok. Here's some photos of the damage, so hopefully this will make more sense. The threads at the bottom of one needle jet are a little jacked up. Should have used a brass drift, but patience was never one of my strong points. Always learn the hard way. I'd save myself twice the money I spend just getting the right tool for the job. <sigh> Someday I'll learn...

I apologize again for the lengthy post. Just like to make sure everyone has enough info.

Jay

Srinath

Heli coil it. Easy, you have access to both sides of it, just knock the tang off when you're done and get it out from the other side and you're good.
Cool.
Srinath.

despecial

- that jet is nice and black...have you had a popping problem? or a coke build up preventing the valves from sealing properly? or some such other problem? (black=rich or oil)

suiteo

Yeah, right cylinder was popping pretty bad. I've ordered new jets from Mikes and a set of needles from xsjohn to properly jet the carbs to hopefully eliminate the problem. Needles came today, waiting on the parts from Mikes to complete the rebuild. Is there a store that a heli coil kit can be picked up, like an auto parts store? And is there a particular thread count I'm looking for? I didn't see anything that actually threaded into the bottom of the needle seat, so I'm not sure what the threads are for. Thanks again

Jay

despecial

- think youll find your main jet goes in here - try recutting threads with a tap first

RandyRyder · Full Member Joined: Sep 27, 2009 Posts: 33

I wouldn't horse around with it. I'd just replace it. Hell I'd probably replace 'em both just to keep a matched set in there.

One thing I'm certain of is that they both need a good soak in a bucket of Gunk and scrubbed with a wire brush. And unless you got a bore brush small enough to clean inside them, I don't think that black one is ever gonna smooth out for ya.

Yer gonna put new needles in them crappy old seats -- would you put new valves in worn-out guides?

weekendrider

A wooden dowel works well for driving them out/in.
The thread count and pitch do matter when using helicoil's. It might be tough to find that size. New jets are probably the cheapest/fastest fix. Especially if your are putting new needles in.

Srinath

RandyRyder wrote:

I wouldn't horse around with it. I'd just replace it. Hell I'd probably replace 'em both just to keep a matched set in there.

One thing I'm certain of is that they both need a good soak in a bucket of Gunk and scrubbed with a wire brush. And unless you got a bore brush small enough to clean inside them, I don't think that black one is ever gonna smooth out for ya.

Yer gonna put new needles in them crappy old seats -- would you put new valves in worn-out guides?

Its not a needle seat, its emulsion tube, the needle does go through it, but that thread in the bottom - well its only job other than not letting in gas around the threads is to hold the main jet in there.
Helicoil is the way to go IMHO ... or a generic version of heli coil, like permacoil or this or that.
Get the right thread measured, I wanna say its a 5mm std thread if I remember and get looking on fleabay.
I may be able to do it for you, I have a few of the common jap bike sizes and this certainly is one. $10 and return shipping. And on gstwin.com I have done several 100 carbs for people. On that site I go by the handle of "the buddha" ... long story, dont ask. I have heli coiled cam caps on gs500's but not this, closest I did was the bling cap on a seca carb.
Cool.
Srinath.

despecial

- by the time you buy the helicoil gear and cost your time i guess its cheaper to buy new brass

RandyRyder · Full Member Joined: Sep 27, 2009 Posts: 33

Srinath wrote:

Its not a needle seat, its emulsion tube, the needle does go through it, but

There is no but. The needle goes through them crappy old seats, just like the valve stem goes through a guide. If the fit isn't right between the valve stem and guide, the engines sucks oil through the guide and the valve doesn't seat right on the head.

In this case the inside of that seat is NOT smooth and perfectly round. It has deposits of crap built up on it here and there. The needle may stick, or it may be pushed off center-bore so it doesn't fit perfectly into the jet.

And I say: If you can't get the guide perfectly clean or if the guide is in some way deformed, the only answer is a new guide.

On the other hand, you can fart around tearing it apart and cleaning it and putting it back together. It's great practice at carb disassembly/reassembly. If that's how a guy wants to spend his days, it's OK with me.

I'm out of here.

Joseph · Full Member Joined: May 22, 2007 Posts: 767 Location: NY

I'd say new needle jets if you can fit them in your budget. If not in budget clean them as best you can inside and out, maybe use pipe cleaners to help. If you cant get the jet to thread into it I'd trash it. I bet you can clean that thread and get the jet in. Dont forget the washer before the jet.

suiteo

Thanks all for the input. Very helpful indeed. Hindsight being what it is, I should have just ordered some new seats, but didn't think about it at the time. Budget is tight (dang ex-wife) so new seats will have to wait until payday. Blew my wad and then some just trying to get this done before the weekend. Amazing I'm willing to go without food just to go for a ride. Very Happy

I'm going to try and tap the threads and clean the crud out of them as best I can and see how it does. Odd thing is I ran by the local hardware place and tried to test the threads on one of those display units they have set up. M5 threaded a little snug, but 10/32 threaded well on the good seat. Doesn't make sense to me, but I'm assuming it's metric since its a metric bike.

Supposed to be 91 on Saturday and a great day for a ride. Haven't been on the bike in a couple of months due to some other issues and I really need to get out. If it doesn't work, well lesson learned to not be so ham-handed with brass items, and I'll replace accordingly as soon as I'm able. Will keep you posted to see if I can get the bike on the road by Saturday. Thanks again all for your insight and help.

Jay

despecial

- i wonder what effect soaking the needle jet(s) in oven cleaner or paint stripper would have

suiteo

Ok. So I got every thing really clean and reassembled the carbs. Got the needle seat issue taken care of, and the jet screwed in without any problems. Put the carbs on the bike, and it fired up on the third kick after not being started for 3 months. Thought I was doing pretty good. Synced the carbs which were pretty far off and the bike smoothed out pretty well. Reved ok, but has some hesitation when applying throttle. Here's the strange thing. The bike will run for a few minutes, and then die, and i have a hard time starting it. And when it is running, when I take the vacuum cap off the left carb port, it runs ok, but as soon as I put the plug back on, it dies. Doesn't happen on the right carb. Here's what I've done so far:

Fully cleaned the carbs inside and out.
Installed new xsjohn jets with small spacer and clip in the middle position
Installed new 135 main jet
installed new 45 pilot jet
Adjusted the floats to 27.3mm
installed new float needle, seat, and float bowl gasket.
Installed new mixture screws, rubber washers, and metal washers
set mixture screws at 2 1/2 turns from bottom

Any ideas what I might look at next? I've got the carbs back out, and am just throwing darts at this point...

suiteo

Alright, so I found part of the problem. Helps if you put the pilot jet in the right spot. DUH. Anyway, now there is a different issue. From 1/2 to WOT the bike is stumbling and falling on its face. If I crack open the throttle all of the way, the bike sputters, stumbles, and then wants to die after bringing it back down. Seems like the left cylinder is running much worse than the right. If I'm reading correctly this is the needle jet set at the wrong height? Is this the part of the carb that affects the upper end of the throttle? Seems like it's starving for fuel when at WOT so if I drop the clip on the needle, this would allow more fuel at mid to WOT? I've read so much I think I'm all confused now...

Jay

xsjohn

Not sure what you have done to the carbs but the needle clip in the middle position """"is correct"""""........ did you put the stock spacer on the needle ........and did you also put the rubber plugs over the pilot jets.........WOT is some needle but mostly main jet.........are the slide rubbers in good condition..........and what kid of air cleaners are you using........

Sounds like something wasn't cleaned or assembled properly...was cleaner coming out the three tiny holes in the throat from the pilot circuit..... and did you change out that needle jet with the YO.............the 336 YO is kinda rich for my needles............what do the plugs look like...........white or black........

Two weeks ago a member sent me Some BS34's to clean and install needles and jets...............he sent along new mix screws to install.............they were totally different looking without the tiny point like the stock mix screws...........they surely would have dicked the mix screw circuit.............

When you set the floats at 27mm ......that is without the needle spring being depressed ....correct....

xsjohn

Srinath

RandyRyder wrote:

Srinath wrote:

Its not a needle seat, its emulsion tube, the needle does go through it, but

There is no but. The needle goes through them crappy old seats, just like the valve stem goes through a guide. If the fit isn't right between the valve stem and guide, the engines sucks oil through the guide and the valve doesn't seat right on the head.

In this case the inside of that seat is NOT smooth and perfectly round. It has deposits of crap built up on it here and there. The needle may stick, or it may be pushed off center-bore so it doesn't fit perfectly into the jet.

And I say: If you can't get the guide perfectly clean or if the guide is in some way deformed, the only answer is a new guide.

On the other hand, you can fart around tearing it apart and cleaning it and putting it back together. It's great practice at carb disassembly/reassembly. If that's how a guy wants to spend his days, it's OK with me.

I'm out of here.

No this is wrong on so many levels.
The first point is, yes needle goes through the emulsion tube correct, however 2 huge differences between it and the valve guide vs valve. Valve and guide are in contact all around and supposed to keep oil out and some of the heat transfer done out of the valve stem. Emulsion tube and needle are not in contact, should not be in contact on a constant basis and the gap is designed to let fluid (gasoline) flow though in copius quantities.
And 2, the needle does not run all the way through the emulsion tube and stick out the bottom as it sits in the carb. That part of the needle is rather very small, its tapered to a near point as it were, so it will not get pushed at all. needle sticking in the emulsion tube, I have see some seriously bad crabs, but never a needle stuck in the emulsion tube. Slides sticking to the wall and the white guide (in carbs that have those, like GS500 carbs) yes, never needle in emulsion tube. The holes on the sides of the emulsion tube getting blocked is a bigger issue than needle getting stuck.

The threads on the bottom serve 2 purposes only. Hold the main jet there and not let fluid through that has not gone through the main jet. A heli coil will cover both jobs well.
Of course a heli coil kit comes with 20 threads a tap and install tool and a breakaway tool all of which costs 75 bucks. Practical reasons make it un suitable, a emulsion tube costs whatever your local junkyard will let you pull em off a junked carb rack for.
I have this size helicoil and am 3/4 of the way in the thread pack having fitted it to many other locations, so in my case, I will helicoil it in the time it takes to get the pic posted on the site. Else ... your preferred fix is fine.
I would have helicoiled it and it will have been a permanent fix and been the fastest and cheapest for me.
Cool.
Srinath.

xsjohn

Good way to clean the inside of the needle jets is to use the paper stick from a q-tip and carb cleaner.............that one needle jet looked crudded and they have to be clean inside and out and the tiny emuslion holes on the side of the needle jet........

And a hardwood dowel is good for tapping out the needle jets on the BS34.......

xsjohn

suiteo

xsjohn. I was hoping you'd chime in here. Smile

To answer your questions:

The stock spacer is on the needle, however, now that I'm thinking of it. I'm not sure if I put the rubber plugs over the pilots. Questioning everything I do now. Have to check that after work now to make sure. The second time I took the carbs out, I blasted them yet again with carb cleaner, and used some nice small bore brushes for cleaning air guns that I found. Various sizes that fit almost all of the passages, so the inside of the needle jets are really clean, as well as the outside that I worked on to get much cleaner than they were. I used the needle jet that was in there, but didn't verify which it was and am assuming it is stock. Have not checked the plugs yet, as I haven't been able to run the bike long enough to see a result. Slide rubbers are in good condition and take more than 5 seconds to fall when covering the hole. I'm using UNI foam style air filters. The mix screws I installed were from Mikes, and the rubber and metal washers under the screw are in place. When I set the floats, i inverted the carbs and set the height with the floats resting on the needles. Thanks for the suggestions.

Jay

xsjohn

Didn't I send the wire for the 46 pilot........sure would do that.....I have left the rubber plugs out myself...........very rich especially on heavy throttle...............

Some allens in the float bowl....(home depot or the like)...

Did the new mix screws look ""just"" like the old ones.............

xsjohn

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