Carb experts, I need your help..

AKmotorider
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AKmotorider
Edited Date/Time 6/3/2016 3:22pm
Recently, a vent hose fixture broke off on the carburetor of my 2014 Husky TC 250. I tried a custom fix but it didn't work. I don't want any dirt getting into the carb. What should I do here? Can I JB weld the hole shut or is that a bad idea? Does anyone know what part of the carb this vent hole is relevent to? I don't want to have to buy a new carb if I don't have to, but the current situation is preventing me from riding.

EDIT: Please disregard all the dirt, this is an old picture before I cleaned it, it's no longer there. But the hole is. Left side of bike next to the choke.




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AKmotorider
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AKmotorider 5/30/2016 2:15pm
5/30/2016 2:15pm Edited Date/Time 5/30/2016 2:17pm
slipdog wrote:
Here ya go.

http://www.ebay.com/itm/Hose-ID-1-4-Barb-x-1-16-Male-NPT-Water-Fuel-Oil…
I considered something like this but my confusion turned me away from it. I don't understand how this would work. Is that the right size? The hole is 2.5 mm large and 1/16 of an inch is about 1.6 mm. How would installation work? Wouldn't I have to drill it? Then I'd have to take the carb apart to get the shavings out??

Plus, the picture shows the thread area being much wider than the barb area, even though the barb area is supposed to be a 1/4 inch and the thread area only 1/16 of an inch. Is the picture not to scale?

As a 21 year old man I shouldn't be this confused, but I am.
cwtoyota
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cwtoyota 5/30/2016 2:21pm
5/30/2016 2:21pm Edited Date/Time 5/30/2016 2:23pm
AKmotorider wrote:
Recently, a vent hose fixture broke off on the carburetor of my 2014 Husky TC 250. I tried a custom fix but it didn't work. I...
Recently, a vent hose fixture broke off on the carburetor of my 2014 Husky TC 250. I tried a custom fix but it didn't work. I don't want any dirt getting into the carb. What should I do here? Can I JB weld the hole shut or is that a bad idea? Does anyone know what part of the carb this vent hole is relevent to? I don't want to have to buy a new carb if I don't have to, but the current situation is preventing me from riding.

EDIT: Please disregard all the dirt, this is an old picture before I cleaned it, it's no longer there. But the hole is. Left side of bike next to the choke.




1) Plug that hole with a rubber plug or an ear-plug or something like that.

2) Wash the bike thoroghly and remove the carb or rotate it out to the side so you can access the top vent-tube nipple.

3) Remove the upper vent tube hose and the rubber plug from step 1.

4) Coat the outside of a piece of your brass tubing in some JB-Weld (or other epoxy).

5) Slide the tube down through the upper nipple far enough that it blocks off the hole where the broken nipple used to be. Pack a little epoxy into that broken hole for a good seal. Then let the epoxy cure.

6) Find yourself a plastic tee fitting and install it in the upper vent tube.


Back in the day the carbs didn't have a vent tube with a drain. If fuel splashed up in the vent tubes, it could cause the bike to bog. Most racers installed plastic Tee fittings above the carb to allow fuel to drain out of the vent hose.
Eventually the manufacturers re-tooled the carburetor casting dies and included the Tee-fitting in the carb body. The lower the drain portion of the Tee is, the better it works, but you still have the vent on the other side too, so it shouldn't cause you a problem.
slipdog
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slipdog 5/30/2016 2:23pm
5/30/2016 2:23pm
Then you'll want a 1/8'(3.175") ntp to 1/4' barb fitting. Yes you have to take the carb apart and yes you have to drill and tap the hole. National pipe thread(ntp) is a self sealing tapered thread that wont leak once installed. If you cant handle that you should hire someone or buy a new carb.

The Shop

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slipdog
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slipdog 5/30/2016 2:24pm
5/30/2016 2:24pm
I've never done this to a carb, just trying to give you a fix for your problem.
cwtoyota
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cwtoyota 5/30/2016 2:31pm
5/30/2016 2:31pm
slipdog wrote:
Here ya go.

http://www.ebay.com/itm/Hose-ID-1-4-Barb-x-1-16-Male-NPT-Water-Fuel-Oil…
AKmotorider wrote:
I considered something like this but my confusion turned me away from it. I don't understand how this would work. Is that the right size? The...
I considered something like this but my confusion turned me away from it. I don't understand how this would work. Is that the right size? The hole is 2.5 mm large and 1/16 of an inch is about 1.6 mm. How would installation work? Wouldn't I have to drill it? Then I'd have to take the carb apart to get the shavings out??

Plus, the picture shows the thread area being much wider than the barb area, even though the barb area is supposed to be a 1/4 inch and the thread area only 1/16 of an inch. Is the picture not to scale?

As a 21 year old man I shouldn't be this confused, but I am.
That nipple won't do you any good.

1/16" is not the thread diameter, it is 1/16" Pipe Thread (NPT). Nominal pipe size is based on a measure of the ID of the pipe, so in reality, a 1/16" NPT has an outside thread diameter of 0.313 inch, there isn't enough material in the casting to drill and thread a hole that large.


Another option if you want to use the stock location is to press-fit a nipple in that hole.
Take a look at the brass overflow drain nipple on most Japanese carb float-bowls... They are brass tubes like you had in your other thread that have been press fit into a precisely drilled under-sized hole.

To do that you'll need to measure the exact diameter of your brass tubing and find a drill bit that is about .010" to .005" smaller than the tubing to drill out that hole. Then you can cut a piece of tubing, chamfer the edge and drive it in with a piloted-punch tool.
Uncle Tony
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Uncle Tony 5/30/2016 2:36pm
5/30/2016 2:36pm
We have dozens of old carbs at the shop, I can break you off a half dozen or so,I can send that little tube part and maybe JB weld it to your carb or you can have it welded by a competent welder (we have a guy around here who can fix it) but that wouldn't be cost affective, PM me if interested, BTW you need that vent do not block it off good luck man
cwtoyota
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cwtoyota 5/30/2016 2:37pm
5/30/2016 2:37pm Edited Date/Time 5/30/2016 2:39pm
This is the press-fit type of nipple I mentioned in my last post. It is probably the only high quality repair you can do to save that carb body.


AKmotorider
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AKmotorider 5/30/2016 6:49pm
5/30/2016 6:49pm
digger wrote:
The last time this happened to me,I used one thesehttp://www.partzilla.com/parts/detail/suzuki/SP-16910-09401.html It's a power valve breather off a late model rm250. I believe the part that would...
The last time this happened to me,I used one thesehttp://www.partzilla.com/parts/detail/suzuki/SP-16910-09401.html It's a power valve breather off a late model rm250. I believe the part that would press into the carb is just over 2.5mm and I don't remember having to drill the carb at all.
Thanks everyone, you're all very helpful. Without your help, I probably would have resorted to buying a new carb, because I didn't know about any of these things. Digger, I ordered a couple of those. I hope they fit. If not, I'll resort to toyota's method.
cwtoyota
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cwtoyota 5/30/2016 6:54pm
5/30/2016 6:54pm
digger wrote:
The last time this happened to me,I used one thesehttp://www.partzilla.com/parts/detail/suzuki/SP-16910-09401.html It's a power valve breather off a late model rm250. I believe the part that would...
The last time this happened to me,I used one thesehttp://www.partzilla.com/parts/detail/suzuki/SP-16910-09401.html It's a power valve breather off a late model rm250. I believe the part that would press into the carb is just over 2.5mm and I don't remember having to drill the carb at all.
AKmotorider wrote:
Thanks everyone, you're all very helpful. Without your help, I probably would have resorted to buying a new carb, because I didn't know about any of...
Thanks everyone, you're all very helpful. Without your help, I probably would have resorted to buying a new carb, because I didn't know about any of these things. Digger, I ordered a couple of those. I hope they fit. If not, I'll resort to toyota's method.
BOOM! Digger with a great repair part.

That's an awesome solution to have in your "back pocket"... I've never broken a carb like that, but I'll save that part number in case it happens.

If you do have to drill it out, make sure you drill it undersize. A little drip of red loc-tite can help if you aren't confident with the press-fit.
colintrax
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colintrax 5/30/2016 11:29pm
5/30/2016 11:29pm
I'd suggest you go with a press fit barb. If you want I'll dig through my machining handbook to find what size barb you'll need, and what size hole to drill.
AKmotorider
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AKmotorider 5/31/2016 3:55am
5/31/2016 3:55am
colintrax wrote:
I'd suggest you go with a press fit barb. If you want I'll dig through my machining handbook to find what size barb you'll need, and...
I'd suggest you go with a press fit barb. If you want I'll dig through my machining handbook to find what size barb you'll need, and what size hole to drill.
I appreciate the offer, and will certainly take you up on that if the part that digger suggested doesn't fit well. I ordered a couple of them, and if they fit well then I won't need to drill it. But if I do need to drill, I won't hesitate to ask you.
colintrax
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colintrax 5/31/2016 9:40am
5/31/2016 9:40am
AKmotorider wrote:
I appreciate the offer, and will certainly take you up on that if the part that digger suggested doesn't fit well. I ordered a couple of...
I appreciate the offer, and will certainly take you up on that if the part that digger suggested doesn't fit well. I ordered a couple of them, and if they fit well then I won't need to drill it. But if I do need to drill, I won't hesitate to ask you.
Well the reason I'm offering to find what the appropriate size is, is because if you go with too loose of a fit it'll fall right back out. If you go tight, it might Crack.
Besides I rarely open my handbook anymore, I need to shake the cobwebs off it Sad
AKmotorider
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AKmotorider 5/31/2016 12:50pm
5/31/2016 12:50pm
AKmotorider wrote:
I appreciate the offer, and will certainly take you up on that if the part that digger suggested doesn't fit well. I ordered a couple of...
I appreciate the offer, and will certainly take you up on that if the part that digger suggested doesn't fit well. I ordered a couple of them, and if they fit well then I won't need to drill it. But if I do need to drill, I won't hesitate to ask you.
colintrax wrote:
Well the reason I'm offering to find what the appropriate size is, is because if you go with too loose of a fit it'll fall right...
Well the reason I'm offering to find what the appropriate size is, is because if you go with too loose of a fit it'll fall right back out. If you go tight, it might Crack.
Besides I rarely open my handbook anymore, I need to shake the cobwebs off it Sad
That's a very good point. In fact, I'd be interested in knowing what size barb and hole to drill. It is a 2.5 mm hole, I believe. This information could come in handy.
AKmotorider
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AKmotorider 6/2/2016 7:40pm
6/2/2016 7:40pm
digger wrote:
The last time this happened to me,I used one thesehttp://www.partzilla.com/parts/detail/suzuki/SP-16910-09401.html It's a power valve breather off a late model rm250. I believe the part that would...
The last time this happened to me,I used one thesehttp://www.partzilla.com/parts/detail/suzuki/SP-16910-09401.html It's a power valve breather off a late model rm250. I believe the part that would press into the carb is just over 2.5mm and I don't remember having to drill the carb at all.
Unfortunately digger the part arrived today and it is waaay too big. Your memory must be faulty because this is nowhere near 2.5 mm. I'm going to have to try something else. Look at the size difference.

The one on the right is 2.5 mm.

Anybody have a suggestion on how to drill this?
AKmotorider
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AKmotorider 6/2/2016 7:43pm
6/2/2016 7:43pm
The Rock wrote:
Your title said experts so my advice is to call an expert. If memory serves correct believe Dick's Racing has a specific mod for your year...
Your title said experts so my advice is to call an expert. If memory serves correct believe Dick's Racing has a specific mod for your year and model Husky that could also be done during the repair. Good luck!

https://www.dicksracing.com/motorcycle_performance/4-stroke



Thanks for the recommendation but I'm not interested in mods or having somebody else repair it. I'm either going to repair it myself or buy a new carb. Just looking for "expert" advice.

Pit Row

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outbackmytrack 6/2/2016 8:38pm
6/2/2016 8:38pm
I have fixed this before.

I had access to many carbs/barbs/90 degree barbs to find the right fitting barb, that was key in finding the proper fit.
I destroyed a couple old carb bodies removing barbs to test in the hole, once I found one I was happy with I stripped the broken carb and heated the hole with a mini torch, I then lightly pressed in my new/used barb.
I couldn't thread the hole because the material was to thin.
Understand i had to search for the right fitting piece, if you do not have access to some brass tubing from old carbs this fix will be hard, every brass tube looks like it will fit, but it has to be he perfect size to really be fixed for good.
Before I had the proper brass piece I went through 4 wrong ones.
Hate to say it but if you can find a used carb for super cheap it is the best fix, because I have done this fix and time vs finding the right barb made this repair a loser for me. I did help a customer, but it cost me money to save him money.
If you try to thread the hole I would go to 3mm and get one of these.
http://www.amazon.com/Male-Thread-Pneumatic-Tube-Fittings/dp/B00880BBPW
gsxr6
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gsxr6 6/2/2016 10:11pm
6/2/2016 10:11pm Edited Date/Time 6/2/2016 10:14pm
Is it a quad vent pwk?...., the previous design got away with half the vents.....and if u plug that vent( with jb) it will work fine if it's a quad vent. It's gonna crack the carb trying to interference fit a tube into it.....that's pretty weak cast aluminum, as I'm sure u realize due to it breaking so easy in the first place. Those vents only allow atmospheric pressure access to the top of the gas in the float bowl, and in its original design these carbs only had two. They worked fine. The four vent setup is insurance for if any of them become plugged.........3 is still enough.
gsxr6
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gsxr6 6/2/2016 10:28pm
6/2/2016 10:28pm
The quad vent pwk actually only have 2 vents, each with a lateral nipple and vertical nipple. Looks like yours is only like that on one side( the side that didn't break). From what I can see in a microfiche yours has 3 vent tubes, the right side of the carb has two and the side u broke only has one. In that case I wouldn't plug it.
gsxr6
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gsxr6 6/2/2016 10:32pm
6/2/2016 10:32pm
Any late model KTM carb can replace it since probably 2000 or so onward. Also the 125 carbs are 38mm, yours is a 36mm. It's well known the bigger carbs offer almost identical low and mid with a noticeable increase in top end and over rev. Dicks makes good money boring those carbs to 38mm.......when a 2001 KTM carb from eBay is a bolt up, and if u choose the right model will be a 38mm. Heck KTM is even putting tmxs on them now, bet u could find someone on this forum who would GIVE u one of those carbs. Lol
gsxr6
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gsxr6 6/2/2016 10:38pm
6/2/2016 10:38pm
that's a 39mm.....and it has four vents in case this ever happens again. It offers more top end increase than any aftermarket pipe will give u as well.....

AKmotorider
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AKmotorider 6/2/2016 11:21pm
6/2/2016 11:21pm
gsxr6 wrote:
The quad vent pwk actually only have 2 vents, each with a lateral nipple and vertical nipple. Looks like yours is only like that on one...
The quad vent pwk actually only have 2 vents, each with a lateral nipple and vertical nipple. Looks like yours is only like that on one side( the side that didn't break). From what I can see in a microfiche yours has 3 vent tubes, the right side of the carb has two and the side u broke only has one. In that case I wouldn't plug it.
Wow, that's what I wanted to know. I didn't know that vents were for the gas in the bowl, as far as I knew it could've been a vent for a different section. By the way, it is a quad vent carb. It is only hard to tell because the carb is caked in dirt, but directly above the piece that broke off is a vertical vent tube. I might just plug the hole and make sure that remaining three vents are clean and free of dirt .
AKmotorider
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AKmotorider 6/3/2016 1:53am
6/3/2016 1:53am Edited Date/Time 6/3/2016 1:57am
gsxr6 wrote:
[img]https://p.vitalmx.com/photos/forums/2016/06/02/137645/s1200_Screenshot_20160602_223622.jpg[/img] that's a 39mm.....and it has four vents in case this ever happens again. It offers more top end increase than any aftermarket pipe will give...
that's a 39mm.....and it has four vents in case this ever happens again. It offers more top end increase than any aftermarket pipe will give u as well.....

Here's a better picture, it's got another vent tube coming out the top there. So this is the quad vent?


gsxr6
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gsxr6 6/3/2016 6:42am
6/3/2016 6:42am
Indeed. U need to cover that hole without plugging the passage.
gsxr6
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gsxr6 6/3/2016 3:22pm
6/3/2016 3:22pm
If u press fit a nipple into that hole too far, it's just gonna block the vent anyways. But if u cover the hole, the upper nipple will still be a sufficient vent. So long as the passage is not blocked. Judging by ur picture I believe a nipple will have to be pressed enough in to not fall out, that the passage would be basically blocked . If it was mine I'd put a coffee stirrer or something that would fit in through the top nipple and down past the hole. Then jb the hole, when dry remove the stirrer and u should be set just fine.

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