Topic: 750 roundtop ( 7A) carb bowl gasket area "weeping"

[DH]

#3 carb bowl leaking. It appears to be coming from the bowl gasket area.
I have changed the bowl, the gasket, the bale clip, then loosened the phillips
screws that mount the carb to the rack, and THEN installed the bowl. The last
two steps have slowed the leak, but haven't stopped it. Not much to blame it on.
Any words of wisdom? I'm out of ideas... I've done the clear tube method, and the level is a little close to the top of the bowl maybe 3 mm. But nothing is running out the overflow. Thing leaks just sitting with engine off.

[lucky]

I would set the float level the way the Clymers' workshop manual describes.

NOT with the so called "clear tube method".

Make sure you have a good float needle and seat.
Toothpaste is not a machining tool.

[DH]

I should've mentioned, I did check the float height and its very close to spec.
i just used the clear tube to see whats up inside. The gaskets should be able to seal
completely tho, correct? I wonder if there's a crack in something where I can't see?
Gaskets are not new, but in good condition/fitment. I've tried several different ones. Bike on sidestand promotes the leak. Still maybe a fuel level issue (too high)?
I have the air cleaner removed, but can't really tell for sure if gas is running down the carb throat. It seems to run good tho. This one is messin with me.

[Don R]

Hit it with a hammer, if it breaks it needed replacing anyway.

 Seriously, if the fuel level is below the gasket there must be a crack or something. As a plumber I've always tried to check above the obvious leak for one not so obvious. Once I had fuel seeping from the petcock and running down the hose, dripping and showing up at the float bowl. Good Luck

[DH]

Hit it with a hammer, if it breaks it needed replacing anyway.

 Seriously, if the fuel level is below the gasket there must be a crack or something. As a plumber I've always tried to check above the obvious leak for one not so obvious. Once I had fuel seeping from the petcock and running down the hose, dripping and showing up at the float bowl. Good Luck




I'm about to that point Don, (The hammer trick) and I have extra bowls. But even replacing with a good one doesn't help. Oh well, i got time. Wish I still had good vision.

[Don R]

It sounds like you've tried all the normal things. Warped carb base?  I'm a fan of the clear tube method, it proves whether you got your float set right when you set them.  It's just one more tool in the toolbox. 

We had a pipe thread leak once. We changed the fitting, it leaked, changed the pipe still leaked. We changed the fitting and the pipe again, yep still leaked. We re-installed the first fitting, no leak.  Just so you know, it happens.

[greenjeans]

What kind of gaskets did you use ?    I'm finding that with aftermarket gaskets that are not Honda and that ethanol crap we're forced to use, I see some of mine weeping ever so slightly.   I also use the clear tube method, and park them on the engine stand so the bowls are level - but still, I see some slight weeping that I've never really had before.   Haven't ordered new Honda gaskets, but was thinking about it.  I currently have some ebay gaskets in both of mine that are new.

You might also check the gasket surface of the carb body.  Alot of times I find old gasket or sealant residue.  Make sure all that is out of there.

[hoodellyhoo]

I had a similar issue on a 750. I would go through everyone else's suggestions first and if that doesn't work, try fitting the bowl without the gasket. When I did this I found that the bowl wasn't bottoming on the gasket seat but instead was getting hung up on one of the float pin holders. A little bit of sanding and everything fit together nice again.

[DH]

I had a similar issue on a 750. I would go through everyone else's suggestions first and if that doesn't work, try fitting the bowl without the gasket. When I did this I found that the bowl wasn't bottoming on the gasket seat but instead was getting hung up on one of the float pin holders. A little bit of sanding and everything fit together nice again.

What area exactly did you smooth sir? This makes sense, and it tells me that I should stop tapping on the bowl....is it that shiney tip on the end of the post?

[hoodellyhoo]

is it that shiney tip on the end of the post?

Yessir. I think I put the bowls on and tried to move them around a little to identify where they were touching. There was some scuffing there on the post so that's where I ground a little off. Took a few tries but I eventually got the bowl to seat fully.

[hoodellyhoo]

Thing leaks just sitting with engine off.

Just re-read your fist post and saw this. Mine would only weep after riding it. When you say it weeps with the engine off, is that on the side stand or center stand? If on the center stand you definitely want to look more closely at your fuel level/float height.

[harisuluv]

I think the simplest solution to this problem would be to buy new bowl gaskets.  If I'm correct you're saying you haven't replaced them just tried different ones.  They get hard and won't seal like a new one.

[DH]

Thing leaks just sitting with engine off.

Just re-read your fist post and saw this. Mine would only weep after riding it. When you say it weeps with the engine off, is that on the side stand or center stand? If on the center stand you definitely want to look more closely at your fuel level/float height.

On  its sidestand is when it leaks...w/fuel turned off. Verified float height and fuel level several times.

I think the simplest solution to this problem would be to buy new bowl gaskets.  If I'm correct you're saying you haven't replaced them just tried different ones.  They get hard and won't seal like a new one.

Yeah, I agree, and haven't done that yet. I'm almost sure there arent any new locally either
I will check the previous suggestions tho, just to rule them out. Thanks for the ideas guys.

[Finnigan]

Check to make sure the surface or brass drain pipe isnt cracked?

[DH]

Check to make sure the surface or brass drain pipe isnt cracked?

Yup, and it was ok. Usually when thatt happens tho, it leaks out the overflow tubes rather than the gasket  surface.

What kind of gaskets did you use ?    I'm finding that with aftermarket gaskets that are not Honda and that ethanol crap we're forced to use, I see some of mine weeping ever so slightly.   I also use the clear tube method, and park them on the engine stand so the bowls are level - but still, I see some slight weeping that I've never really had before.   Haven't ordered new Honda gaskets, but was thinking about it.  I currently have some ebay gaskets in both of mine that are new.

You might also check the gasket surface of the carb body.  Alot of times I find old gasket or sealant residue.  Make sure all that is out of there.

I'm using used gaskets on all 4 but only one leaks (#3)..I may be forced to use genuine honda if all else fails. I hear ya on the ethanol. Wondering how long
before all the rubber parts in the engine are going to dry up, shrink and become rock hard because of it.

[DH]

Just to update,  I left the bike sit for about a week before working on it again. I ran it long enough before parking it to bring the fuel level down in the bowl, and then shut the fuel off. The bowl gasket quit leaking on its own. I suspect it just expanded on its
own after a period of exposure to gasoline. It's now possible to park on the sidestand again. Probably good to change to new gasket
tho. Just thought I'd post the results, if it helps anyone.

[dusterdude]

Been there before,good luck