Me and carbs

[grant.mckenzie]

For some reason, although I'm pretty confident around the atomic 4 these days, me and carbs never really hit it off. Basically every time I have attempted to clean a carb with say idle problems, I generally make the problem worse!

Problem of the day.

Cold start, no leak.

[YOUTUBE]6P0tePhngE4[/YOUTUBE]

After a few minutes running, leak.

[YOUTUBE]ts0ceHDKLKQ[/YOUTUBE]

Its not obvious to me where it is coming from. Gasket fail perhaps?

Any advice welcome.

[joe_db]

IMHO the carb eventually will have issues that aren't fixed by a simple cleaning. I had endless low-speed issues and eventually just bought a new carb. Not saying not to clean it, but they eventually will need more than that.

[roadnsky]

Basically every time I have attempted to clean a carb with say idle problems, I generally make the problem worse!

A bit more info please?
When you say clean the carb... did you take the two halves apart and clean (rebuild) it?

It's really hard to tell from the video footage where exactly the leak originates.
Likely spots are:
• Where the fuel hose connects to the carb inlet
• Where the carb bolts to the manifold
• Where the two halves of the carb screw together

And, in the carb rebuild instructions, this caution...

"Do not over tighten the ½" hex head or the sealing washer is likely to extrude out from under the hex head and cause a leak."

That hex head and washer are exactly where your video shows the dripping.
Although with gravity, a leak from one of the other mentioned sources would appear there too.

[joe_db]

I haven't had it happen, but I have hard of carbs warping so the top and bottom don't mate perfectly. Must be a way to check this, sharpie marker and paper or ???????????

[roadnsky]

I haven't had it happen, but I have hard of carbs warping so the top and bottom don't mate perfectly. Must be a way to check this, sharpie marker and paper or ???????????

Check out John's POST #2 here...

[Al Schober]

The seal between the upper and lower half is NOT a fuel seal - it's an air seal. Put the two halves together with no gasket and test the gap with a strip cut off a file card. If it goes in, you've got some work to do. Oh yeah, that gasket doesn't need sealant.
Take off the flame arrestor and see if you're getting fuel in the inlet.
What do you have for a fuel pump? Any pressure gauge on the carb inlet? If fuel pressure is too high, it could be forcing the float valve open.
Carb to manifold joint is NOT a location for a fuel leak.
My money is on the gasket around the plug for the main jet.