Topic: Gas leaking out left carb??

[messeduptriple]

K so I took the bike in to be done. I replaced the jets from 110 to 120.
Left the idle at 38 I think they are.
I have a 4-1 exhaust.
The guy said that its running a bit too rich. Hard to keep idle.
Gas is coming out left carb. I still need to sync my carbs ... Any ideas what I have to do??? I get the bike back this Thursday and want to take out the carbs and see what's going on? Could it be the floats?? I asked about that once and said that left float didn't seem.very secure when I put it on compared to the rest... Was told it should be fine . Could that float have popped out and that's why gas is leaking out??? What should I check? How do I know what to adjust.. or bump up or down on jets???  Carpy told me to bump up to 120. If that helps any. Any help is greatful thanks !!
76 Honda 550
- cristian
* the bike was taken in to have wireing done and seat mounted and chain on... His carb sync is broken that's why that wasnt done.
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[luap]

I pulled this link from here it has some good reading
http://www.duncanracing.com/TechCenter/KeihinCarbJetting.pdf
Id adjust the float to 22mm manual has a good pick of how to, IMO 120 is to rich

[Flying J]

I would have left it at 110s. Unless carpy had your bike and looked at the spark plugs or did a dyno to tell if you are running lean. Anyway. If your carb is leaking, where is it leaking from? Is it the overflow tube? Then yes your float is not stopping the fuel. Could be that its just hung up or there is some junk caught in the needle. What i do is first bang on the bowl with the handle of a screwdriver. If that doesnt fix it. I turn the fuel off, then i drain the leaky bowl using the drain screw. Then i turn the gas back on. By draining the bowl you open the float needle all the way, then the influx of fuel hopefully clears the passage way of any debris . If that doesnt fix it drop the bowl and see why the float is not working.

Good luck

[messeduptriple]

I would have left it at 110s. Unless carpy had your bike and looked at the spark plugs or did a dyno to tell if you are running lean. Anyway. If your carb is leaking, where is it leaking from? Is it the overflow tube? Then yes your float is not stopping the fuel. Could be that its just hung up or there is some junk caught in the needle. What i do is first bang on the bowl with the handle of a screwdriver. If that doesnt fix it. I turn the fuel off, then i drain the leaky bowl using the drain screw. Then i turn the gas back on. By draining the bowl you open the float needle all the way, then the influx of fuel hopefully clears the passage way of any debris . If that doesnt fix it drop the bowl and see why the float is not working.

Good luck

do you think I should pull the whole carbs out first??? Then go from there??
How do I turn the fuel off? And where is the drain " screw " ? This just seems complicated now... I'm just not sure where to start first... Pull out the carbs or just futs with it first?
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[Mooshie]

I would have left it at 110s. Unless carpy had your bike and looked at the spark plugs or did a dyno to tell if you are running lean. Anyway. If your carb is leaking, where is it leaking from? Is it the overflow tube? Then yes your float is not stopping the fuel. Could be that its just hung up or there is some junk caught in the needle. What i do is first bang on the bowl with the handle of a screwdriver. If that doesnt fix it. I turn the fuel off, then i drain the leaky bowl using the drain screw. Then i turn the gas back on. By draining the bowl you open the float needle all the way, then the influx of fuel hopefully clears the passage way of any debris . If that doesnt fix it drop the bowl and see why the float is not working.

Good luck

do you think I should pull the whole carbs out first??? Then go from there??
How do I turn the fuel off? And where is the drain " screw " ? This just seems complicated now... I'm just not sure where to start first... Pull out the carbs or just futs with it first?
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Well I'm no expert but if your carb is leaking from the overflow tube then to turn the fuel off you would do that at the petcock.  The drain screw is on the bottom/s of the individual carbs it is a copper screw I believe.  Try hitting the bank of carbs with a screwdriver handle first (that worked when my float bowl got stuck on the #3 carb--no problems since-the hardest part was figuring out that it was coming from the #3 carb -I had to trace the overflow tubes back up to the carb bodies-it got crowded under there ).  But if my problem returns then I will assume there is debris and do the next two steps if not 3 steps (turn off petcock and drain the bowl).  Fairly simple steps.  Good luck.

[aperry]

I don't know the history of your bike, but when I rebuilt my 750 K3 carbs and then went to sync them I struggled for hours with leaking issues from the overflow tube.  Tried different float heights, etc.  After scouring this forum I learned that it's not uncommon for the overflow tube to develop a very small crack on the inside of the bowl, which means it'll have a continuous slow drip (as long as the petcock is turned on).

Sure enough, two of my overflow tubes were cracked.  The cracks are kind of hard to see, but definitely there.  Some people solder them closed, some use heatshrink wrap around the tube.  edit:  But don't close off the tube!  I replaced mine with used bowls from ebay ($20 each).

Apparently this is caused by gas freezing in the bowl over the winter in cold climates.

Anyway, maybe worth a look.

Regardless, I wouldn't take the carbs off for this issue.  It is likely something that's accessible by removing the bowl which is super easy (if your carbs are like mine).

Aaron

[Flying J]

If you can not figure out how to turn the gas off you should not be on such an old motorcycle. If you can not figure out what the drain screw is you should not attempt to take the carbs off the bike. If hitting the carbs with a screw driver or draining the bowls sounds confusing you have found the wrong hobby. Lucky for you, if you decide to stick with it there is plenty of help on this forum. We all start somewhere. Download the manual. Read it. It will identify all the parts you are confused about. And then next time you wont have to take your bike to somebody to do wiring or put a chain on because its easy and you can do it yourself.

And aperry is right the overflow tube could be cracked. I would try the other things first since they do not require removing the bowl.

[lucky]

QUOTE:

"K so I took the bike in to be done. I replaced the jets from 110 to 120.
Left the idle at 38 I think they are."

What did you take to be "done" Was it a CB750?
What was done?

To help you this is what i need.


1976 CB750
Exhaust type 4 into 1
Muffler?
Air intake system?
idle jets?
Main jets #120
mixture screws?

Without this information it is impossible to help you.
If you got information from CARPPY it is probably accurate. Thats all he does.
You did not say where the gas is coming out of the carb? THATS FIRST on the list.

Syncing carbs is LAST. The icing on the cake.

Your first step will be removing the rack of carbs from the motorcycle after you drain the float bowls.

Please show us a photo of the carbs with the float bowls off. Thanks

[Flying J]

Lucky read the first post. it says that its a cb550 and why he had it in the shop.

My opinion is removing the carbs because one is leaking is the stupidest idea. Check to see if crud is jamming the valve. Then drop 1 bowl. and see if its a cracked tube. If that doesnt fix it then you may want to take the carbs off and start from scratch. Taking the carbs off is not all that easy.  LUCKY are you going to diagnose a cracked over flow tube or a clogged float valve from a picture?  When you have a problem start with the simplest solution and then move to the more difficult solutions.  As for carpy, he knows  a lot but unless he has your bike he does not know what jetting you need. He can give you a good guess and get you close.

[lucky]

Lucky read the first post. it says that its a cb550 and why he had it in the shop.

My opinion is removing the carbs because one is leaking is the stupidest idea. Check to see if crud is jamming the valve. Then drop 1 bowl. and see if its a cracked tube. If that doesnt fix it then you may want to take the carbs off and start from scratch. Taking the carbs off is not all that easy.  LUCKY are you going to diagnose a cracked over flow tube or a clogged float valve from a picture?  When you have a problem start with the simplest solution and then move to the more difficult solutions.  As for carpy, he knows  a lot but unless he has your bike he does not know what jetting you need. He can give you a good guess and get you close.

I think I am right.
Take the carbs OFF.
The reason is it can be hard to get a float bowl off without damaging the screws when it is on the bike.
Also if the float level is incorrect I would bet they are all wrong.
I would get all new float needles too. If someone tried to adjust the float level because there were old float needles in it.....you get the picture.
Take them off and do it right.

Put in new float needles.
Make sure the idle jets are not clogged.
Write down what size they are.
Clean the float bowls.
Adjust the float levels if they need it.

That is what I would do.-LUCKY

[lucky]

I don't know the history of your bike, but when I rebuilt my 750 K3 carbs and then went to sync them I struggled for hours with leaking issues from the overflow tube.  Tried different float heights, etc.  After scouring this forum I learned that it's not uncommon for the overflow tube to develop a very small crack on the inside of the bowl, which means it'll have a continuous slow drip (as long as the petcock is turned on).

Sure enough, two of my overflow tubes were cracked.  The cracks are kind of hard to see, but definitely there.  Some people solder them closed, some use heatshrink wrap around the tube.  edit:  But don't close off the tube!  I replaced mine with used bowls from ebay ($20 each).

Apparently this is caused by gas freezing in the bowl over the winter in cold climates.

Anyway, maybe worth a look.

Regardless, I wouldn't take the carbs off for this issue.  It is likely something that's accessible by removing the bowl which is super easy (if your carbs are like mine).

Aaron

I think the overflow tubes get cracked from areas that have very cold weather.
The gas or water freezes and expands inside the overflow tube and splits.

[Flying J]

I guess im taking for granted that the carbs have already been cleaned. If you have not cleaned and adjusted the carbs then you need to do that.
As for getting bowls off. I use this tool from harbor freight with a phillips bit.
http://www.harborfreight.com/5-16-inch-side-terminal-battery-ratchet-wrench-97261.html


Once you have the bowl off you can fill it with water and see if it leaks from the overflow tube. Then you will know if your tube leak or not.

[aperry]

I think the overflow tubes get cracked from areas that have very cold weather.
The gas or water freezes and expands inside the overflow tube and splits.

Yeah, I think my 750 has been up here in the Boston area for a while.  The temps can get below zero (F) on certain winter nights, so I wasn't surprised to see the cracked pipes.  When it comes to leaks, this probably is not as common as a bad/dirty valve or incorrect float height, but I just thought I'd mention it because it caused me a lot of grief.

Aaron

[messeduptriple]

I did pull the carbs off when I bought the bike, there was a idle jet clogged I cleaned it..I cleaned them all, replaced the main jets to 120. When I was putting on one of the new jets I noticed that float wasn't really on very secure, I went on this forum and asked specifically about that, I asked is it going to pop out after I flip this over and most said yes it will be fine.. after I put fresh gas inside the tank it was leaking out the left carb only I noticed. I didn't know what to do .... So I finally turned that gas switch off and it stoppped the leak. That was last time I had the bike. Now I was told that its runs good but when on the gas running its leaking gas out that left carb still. If I take the carbs out how do I know how far to set the floats??  I've taken the carbs out twice so I know how to do this fine ...its just now doing the adjustments. I don't WANt to ruin anything on this bike so I just want to do this correct. I know u don't know everything obviously but that's why I'm asking what you vintage gentleman think. 

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[Flying J]

Download the manual. Also in the faq section under carbs are the stock settings for the floats for every model carb. Also make sure your petcock filter is clean.

[bollingball]

K so I took the bike in to be done. I replaced the jets from 110 to 120.

So did you replace the jets or did you have someone else do it? This is a yes or no question.

Left the idle at 38 I think they are.

Do you mean the slow jets are #38? You think they are. What do you know?
Idle is measured in rpm's.

The guy said that its running a bit too rich. Hard to keep idle.
Who is this guy?

Gas is coming out left carb. I still need to sync my carbs ... Any ideas what I have to do???

Yes Stop the gas coming out the left carb and sync the carbs.

I get the bike back this Thursday and want to take out the carbs and see what's going on? Could it be the floats??

It could be a lot of things. At this point I am not sure who has done what I don't even know if you do. If the bike were to come to my shop with what you wrote about in the op I would take the carbs off and start from scratch. There is no way to tell what is inside those things or how they are set up. First I would try to run it to give me some idea how things are working.

Carpy told me to bump up to 120. If that helps any.

So this is the other person? did he have this bike at his shop and told you this after working on this problem?

* the bike was taken in to have wireing done and seat mounted and chain on... His carb sync is broken that's why that wasnt done.

Are you telling us that this man that works on so many bikes only has one carb sync tool? Hell I do it for fun and have three different tools this is hard to believe.

I am with ffjMoore You have bit off a mouth full hope you don't choke. This has to be a project that you are not going to be in a hurry to fix. So take your time read a lot and start learning it can be fun. If you look at it in that way. At this point I would say take a deep breath slow down and learn a good trouble shooting technique one thing at a time in the correct order A community college would be a good place to go . If not motorcycles a small engine repair class.

Ken
 

 

[thrutheframe]

  Triple, am I correct in my assumption that you have your bike back?  If so great and good luck.  To address your issue I agree with FFJ, you have to take this stuff one step at a time.  Before you go any further try putting the bike on the center stand and turn on the gas.  If it stops leaking you most likely just need a float bowl gasket.  If it continues to leak take a rubber mallet or large heavy screwdriver and tap on the bowl of the offending carb.  Sometimes floats get stuck when the carbs are off the bike and inverted or placed on there back/face.  Whatever you don't hit it with a metal object.
  If neither of these methods works you most likely have a mis-adjusted float, a bad float valve or dirty float valve.  You CAN fix that on the bike but it won't be easy.  Fix this problem first and move on from there.  You should under no circumstance ride this bike with a carb leaking. 

[lucky]

I think the overflow tubes get cracked from areas that have very cold weather.
The gas or water freezes and expands inside the overflow tube and splits.

Yeah, I think my 750 has been up here in the Boston area for a while.  The temps can get below zero (F) on certain winter nights, so I wasn't surprised to see the cracked pipes.  When it comes to leaks, this probably is not as common as a bad/dirty valve or incorrect float height, but I just thought I'd mention it because it caused me a lot of grief.

Aaron

Seems like the overflow tube is brass and you should be able to clean it with steel wool or sandpaper and solder it. Easy.

[messeduptriple]

  Triple, am I correct in my assumption that you have your bike back?  If so great and good luck.  To address your issue I agree with FFJ, you have to take this stuff one step at a time.  Before you go any further try putting the bike on the center stand and turn on the gas.  If it stops leaking you most likely just need a float bowl gasket.  If it continues to leak take a rubber mallet or large heavy screwdriver and tap on the bowl of the offending carb.  Sometimes floats get stuck when the carbs are off the bike and inverted or placed on there back/face.  Whatever you don't hit it with a metal object.
  If neither of these methods works you most likely have a mis-adjusted float, a bad float valve or dirty float valve.  You CAN fix that on the bike but it won't be easy.  Fix this problem first and move on from there.  You should under no circumstance ride this bike with a carb leaking.

thanks

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[messeduptriple]

K so I took the bike in to be done. I replaced the jets from 110 to 120.

So did you replace the jets or did you have someone else do it? This is a yes or no question.

Left the idle at 38 I think they are.

Do you mean you mean the slow jets are #38? You think they are. What do you know?
Idle is measured in rpm's.

The guy said that its running a bit too rich. Hard to keep idle.
Who is this guy?

Gas is coming out left carb. I still need to sync my carbs ... Any ideas what I have to do???

Yes Stop the gas coming out the left carb and sync the carbs.

I get the bike back this Thursday and want to take out the carbs and see what's going on? Could it be the floats??

It could be a lot of things. At this point I am not sure who has done what I don't even know if you do. If the bike were to come to my shop with what you wrote about in the op I would take the carbs off and start from scratch. There is no way to tell what is inside those things or how they are set up. First I would try to run it to give me some idea how things are working.

Carpy told me to bump up to 120. If that helps any.

So this is the other person? did he have this bike at his shop and told you this after working on this problem?

* the bike was taken in to have wireing done and seat mounted and chain on... His carb sync is broken that's why that wasnt done.

Are you telling us that this man that works on so many bikes only has one carb sync tool? Hell I do it for fun and have three different tools this is hard to believe.

I am with ffjMoore You have bit off a mouth full hope you don't choke. This has to be a project that you are not going to be in a hurry to fix. So take your time read a lot and start learning it can be fun. If you look at it in that way. At this point I would say take a deep breath slow down and learn a good trouble shooting technique one thing at a time in the correct order A community college would be a good place to go . If not motorcycles a small engine repair class.

Ken

ken... Lol... Yea you put me in my place on that one. Yes I took them off and I replaced the jets to 120. Carpy is the man I bought the exhaust from. The other man is the man that installed all the wireing and seat for me.
He said his sync broke.
He did everything well though I must say.
Like I said earlier that float seemed really loose when I installed that new jet.. I came on here and asked about it.. would it be ok once I flip the carb back upside down and was told it will be fine.... I think something might have popped out... It's still leaking even after this morning I tapped on the bowl with a mallet. Hope this answers a few ?'s Ken.
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[bollingball]

Like I said earlier that float seemed really loose when I installed that new jet.. I came on here and asked about it.. would it be ok once I flip the carb back upside down and was told it will be fine.... I think something might have popped out...

I know it is late now but if this were to happen again turn the carb right side up with the bowl off then work the float gently with your finger to check for any binding. Sometimes little burrs on the side of the hinge or the post will cause it to hang up. After this is done try not to turn the carb upside down any more. Think of these carbs as a pocket watch they are fra gii lee.
 I think you will have to revisit the carbs off the bike (hope not) I know it is a bitty.
 At this point you must find out where the leak is. This could be a few things. First I would dry it really good then put some powder all over the out side then turn on the gas to fill the bowls look at the bowl gasket area if it is there fuel level could be to high then look at the overflow this could be the tube inside or the drain screw not closing good. Start at one spot and make sure it is not that before moving on to the next area you do not want to go back and forth to a place you have allready checked. Stay focused.

Ken

[lucky]

I cannot tell what this "loose" float thing is you keep referring to.

I wish we could see a photo. Maybe a part is broken or missing??
Just cannot tell from your discription.

[Flying J]

It sounds like he is referring to the float needle. I believe he thinks that the float needle was loose and that when he flipped the carbs over it might have slipped out. Two things
1Im not sure you know the differance between a jet, a float and a needle.
2 if you had the float height adjusted right the needle would not slide out.

Float


Float needle. Yours should not have a rubber tip or the metal clip. Also there should be no dime in you carb


Main jet


Pilot jet

[thrutheframe]

Uhhhhhhhh 

[messeduptriple]

It sounds like he is referring to the float needle. I believe he thinks that the float needle was loose and that when he flipped the carbs over it might have slipped out. Two things
1Im not sure you know the differance between a jet, a float and a needle.
2 if you had the float height adjusted right the needle would not slide out.

Float


Float needle. Yours should not have a rubber tip or the metal clip. Also there should be no dime in you carb


Main jet


Pilot jet

lol. Yea thanks for that refrence guide. Yes that float is what i thought pop out. I just got the carbs off. Going to take a look

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[messeduptriple]

I was told to feel the exhaust.... are they all hot... the far right header was cold... was told to look at the jets..maybe something is clogged

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[messeduptriple]

From that ref guide i replaced the main jets left the others alone ...but they were cleaned out ...i did them..one was clogged...i cleaned it

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[Flying J]

Its Not only jets that need to be cleaned. The passageways as well as the emulsion tubes. I thought all my carbs were clean until i punched out the emulsion tubes and this one was not the worst of the 4.

[messeduptriple]

I took the carbs out, the left and the right were clogged... i put them back in the bike.... i absolutely  hate pulling  carbs! 
Anyways, im going to bed ...in the morning ill fire it up and see what  happens.   

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[messeduptriple]

Lil pissed off....its still smoking, the rpms are really high and it dies when  i give it gas. I noticed it was leaking gas out the  right side of carb now. Im just upset now... that was a #$%* to take out and now put in... now i pull them  back out? 

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[Flying J]

Don't do it half ass or you will be pulling the carbs again. Clean everything. Then clean all the holes in the actual carbs. If you can, punch out the emulsion tubes and clean them. Set the float height and make sure none of your overflow tubes are cracked. Then bench sync them. Also your bike will never idle right until you sync the carbs.

[thrutheframe]

Don't do it half ass or you will be pulling the carbs again. Clean everything. Then clean all the holes in the actual carbs. If you can, punch out the emulsion tubes and clean them. Set the float height and make sure none of your overflow tubes are cracked. Then bench sync them. Also your bike will never idle right until you sync the carbs.

I agree with FFJ, you have them off, do EVERYTHING you can.  This is a game of patience and details.  You have a great start on a really nice machine, Your aesthetics are solid so far but think about this as priority list.

1 Safety
2 Reliability
3 Appearance

We all really want to see you succeed!

[messeduptriple]

Don't do it half ass or you will be pulling the carbs again. Clean everything. Then clean all the holes in the actual carbs. If you can, punch out the emulsion tubes and clean them. Set the float height and make sure none of your overflow tubes are cracked. Then bench sync them. Also your bike will never idle right until you sync the carbs.

I agree with FFJ, you have them off, do EVERYTHING you can.  This is a game of patience and details.  You have a great start on a really nice machine, Your aesthetics are solid so far but think about this as priority list.

1 Safety
2 Reliability
3 Appearance

We all really want to see you succeed!

the floats were adjusted but now the bike starts and runs good...only problem now is when I give it gas the bike wants to  putt out a bit
.then seems to catch and then have the power...seems to do this on 4th gear as well..what's going on now? .

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[Flying J]

Could be a million things. Have you synced the carbs? Until you have diagnosing issues is almost pointless.

[messeduptriple]

Could be a million things. Have you synced the carbs? Until you have diagnosing issues is almost pointless.

gotcha

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