Topic: UPDATE: Float gasket expands??? SOLVED

[Nortstudio]

For anyone who read this post last week, I wanted to update it to let people with the potential same issue know how it panned out....

It was the fuel line!  Feel like I should have sussed it out sooner, because the issue was only with carb 3&4. But from looking at it from the angle on the right of the bike, it really looked like it was coming from the float gaskets.  Then today, after two days of no leak, after I had recleaned the gaskets, it started pouring out again.

The lesson here is: listen to Two-Tired.  He mentioned some issues that one might have with alternate style fuel line.  I had a hard time finding the correct size, and early on had bought some of the clear racing style.  It was 1/4" - the stock looking to be 5.5mm I believe.

Long story still too long, I replace the one side today with some rubbery type, closer to the stock size, and leak is gone.

DONE!......hopefully

I had some trouble with my floats leaking the other day. Seemed to be coming from the area where float meets the carb.

I just removed the floats and the gaskets are definitely larger than when I put them in there. They were brand new and fit perfectly (with a dab of glue to hold them in place - since told this may have been a problem). Now I would have to cut a piece out of them to make them fit size wise.

Is this normal???  Do gaskets expand this much???

Thanks

[MoMo]

Yes,  they will.   Try the fridge to make them constrict.  Also, they will somewhat return to the original shape with time.  Larry

[Nortstudio]

Thanks Larry.  It was fairly dramatic, so it seemed as if they were unusable.

I will try the fridge and time to see if that helps.

Appreciate the help.

[Jay B]

I've never put them in the fridge.
They will be fine in a day or so. Nice to have extras around so you have one ready to go in case you need to drop a bowl for somrthing minor

[Old Scrambler]

I am guessing you have installed KEYSTER replacment gaskets or another aftermarket brand. The original gaskets from HONDA are not known to expand. They are still available at most dealers and numerous on-line retailers. No bonding material should be used with fuel..........unless you like clogged jets!!!

[Nortstudio]

They were definitely not Honda. The local dealers here don't carry anything unless you want a helmet that has 14 unnatural colors.

I used a bit of superglue (suggestion here and also I think the PO had done it too). The gasket was round, and the 087a float is anything but round. After te fact I was told about the grease trick - I'll try that if year ever get small enough again - or replacements if not.

Definitely don't want clogged jets, but it all seemed to be there when I opened it up. I usd a pin prick worth, so hopefully I don't hit major snag with that. When I cleaned them the first time, what the PO had dabbed on there was not in the jets, so I'll keep my fingers crossed this time for sure.

Live and learn.

[Nortstudio]

I'm kicking myself for not having extras right now.

I'll let them sit. Can't wrench til monday anyway. Should have just left them outside on te curb with the bike - colder out there than the fridge!

My main question is now: would the expansion cause the leak?  The floats themselves seem to be moving ok.

[Nortstudio]

Anyone have a suggestion for a place that carries OEM Float gaskets for a 1976 cb550k?  Just a name would be fine. All the places I look carry K&L type - which I think I had already.

My normal OEM place is bikebandit and they are unavailable right now. Parts & more has some, but it doesn't list whether they are OEN and the cost is only $2/each so figured that would be aftermarket as well.

Thanks.

[Spanner 1]

Yes!.... the side clearance between the floats and the (normal) gasket is very little. Expanding gaskets due to gas exposure will stop the floats coming-up to close the fill valve.... a very commonly overlooked cause of overflowing/ way rich carbs... and often the seals 'bow in' when your putting the bowl back on ( K1 'thru K6 750 carbs )........ IMHO.

[Nortstudio]

Thanks Spanner. Is there a fix for this issue I should be looking at?

appreciate the heads up.

[Duke McDukiedook]

K&L and keyster gaskets should work fine if that is what you used.
I have used both types on my projects and no problems with them so far.

[FunJimmy]

I've had this problem with O-rings purchased through an industrial supplier.
There must be an issue with the composition of the O-ring and gasoline.
Will have to pass it on and see if there is an alternate material available.

[Nortstudio]

K&L and keyster gaskets should work fine if that is what you used.
I have used both types on my projects and no problems with them so far.

Also, so far carbs 1&2 seem fine. And actually, 3 leaked less than 4. Maybe it's anoter issue, I'll post back when I sort it out. Very frustrating to even think it might be new gaskets. Maybe it was the glue dab to secure it, but I really only used a speck.

[jimkalfakis]

speck = 5mg.  FYI 

[haill]

if you place your gaskets in a pot of boiling water for a couple of minutes then place in the freezer for half hour they will shrink back to the original size, so you can get on with getting it back together.
make sure you use a old pot not your wife's cookware.