Float bowl level, Using bowl level gauge Options

[scrz914]

I bought the float bowl gauge from partsklassik to double check my bench settings on the float and needle valve. I was surprised to see the level rise to the top. I shut the pump off before it overflowed. In reading the instructions I noticed it said to do the check while running the engine. I only ran the pump. Is there any reason to believe the levels would be different between running the engine as opposed to just running the pump? Also, is it possible that the needle valve is just sticking? I’ve heard even new needle valves can be problematic.
I have Weber IDA3C.
Here’s the gauge I bought. Not cheap. But it does come with different needle valve shims.

[brant]

I always have the car running
Why not follow the directions

I use two at the same time. so it goes quicker

[brant]

I think the motor running would change things slightly

The vibration alone

[scrz914]

I always have the car running
Why not follow the directions

I’ll end up doing this eventually. Just trying to avoid running the engine right now as I’m diagnosing some other issues. Was just hoping to get carb and ignition settings close before running the engine. I forgot to say that the engine is newly rebuilt and is on a run stand in my garage.
Thank you though.

[stownsen914]

Yeah running. Needle valves are imperfect even when working "perfectly." With the engine running you account for a little usage and vibration, both of which impact level in the float bowl.

[Superhawk996]

Also, is it possible that the needle valve is just sticking? I’ve heard even new needle valves can be problematic.

To answer your question - the gauge should not have overflowed even with the engine not running.

Yes, the float needle may be sticking - based on your description it most likely is sticking.

Yes, new needles can be problematic. There are two types. One is solid brass or stainless. The other is a solid body but with a viton rubber tip to the needle. Generally speaking, I’ve had better luck with the soft tip needle valves but of course over time the rubber hardens, wears, and then fails to seal. So no perfect solution. Add cheap no-name China made parts to the equation and things get worse.

Note: you don’t mention what your fuel pressure is but carb needles are easily overwhelmed if your fuel pressure is too high - generally 3 psi or so is plenty.

[scrz914]

I went ahead and checked the remaining 3 bowls and realized they wouldn’t overflow. That would be a major design flaw. I’ll have to run the engine to get accurate readings. Just gonna get it warm till it stops backfiring.
I did check psi from both sides of the fuel tee connection and it was 3 psi dead on.
What I’m really chasing is a temperature disparity between the left bank/right bank from readings at the exhaust ports. So I’m starting with the simplest most probable problems. I’m not really experienced with carbs so learning as I go.

[930cabman]

I went ahead and checked the remaining 3 bowls and realized they wouldn’t overflow. That would be a major design flaw. I’ll have to run the engine to get accurate readings. Just gonna get it warm till it stops backfiring.
I did check psi from both sides of the fuel tee connection and it was 3 psi dead on.
What I’m really chasing is a temperature disparity between the left bank/right bank from readings at the exhaust ports. So I’m starting with the simplest most probable problems. I’m not really experienced with carbs so learning as I go.

Could the temperature difference a clogged jet or be other than fuel? compression, overlap, ..

I considered trying this gauge, but used the setup from Pierce, worked perfect

[scrz914]

Could the temperature difference a clogged jet or be other than fuel? compression, overlap, ..

I considered trying this gauge, but used the setup from Pierce, worked perfect

When I first saw the temp differences my mind immediately went to cam timing. But I decided to make the assumption (For now) that the professional mechanic that rebuilt the engine more than likely knew what he was doing and that the amateur that tore apart and cleaned the carbs (me) has more work to do.

What is the set up from Pierce?

[930cabman]

Could the temperature difference a clogged jet or be other than fuel? compression, overlap, ..

I considered trying this gauge, but used the setup from Pierce, worked perfect

When I first saw the temp differences my mind immediately went to cam timing. But I decided to make the assumption (For now) that the professional mechanic that rebuilt the engine more than likely knew what he was doing and that the amateur that tore apart and cleaned the carbs (me) has more work to do.

What is the set up from Pierce?

It states 48 IDA and was unable to find another one. I have a similar or the same. Works perfect. I considered the gauge from PartsKlassik but was unsure how to view it when installed into the car and when removing things could get messy