Carb float heigth

[alberg]

What effect will be noticed if the float is not set correctly. On my A4 it set lower in the chamber than recomended, I have not noticed any engine running problems.
Alberg

[Don Moyer]

Alberg,

Float settings which provide a lower than normal fuel level in the float
chamber will result in a leaner mixture, which as long as your engine runs
OK would more or less be a good thing. Keep your eye on the plugs and look
for a dry light gray color. Be sure that you can still flick the throttle
forward as rapidly as possible without incurring any kind of hesitation in
the acceleration. If you do encounter a bit of hesitation, I'd tweak the
float level back up a bit.

Don

[tenders]

Leaner? I would have thought a lower level would result in less pressure from the float against the needle valve, allowing more fuel to get sucked in and a richer mixture.

[Don Moyer]

Perhaps I misunderstood your description. I thought you had the floats
adjusted so that they would be lower in the bowl when they closed off the
incoming fuel, which would result in a lower level in the float chamber.

Don

[alberg]

Don is correct the fuel level is lower than "normal".

Anyway as a side when at idle my A4 runs a little rough not enough to worry me until now. Yesterday I installed a device that lets me see the actual combustion process. This comprises of a glass centred spark plug that with a small miror allows me to see inside the actual combustion. What I noticed is a blue circle of detonation which is normal, however during the period of hesitation there is no blue detonation only the plug spark I now wonder if lower than normal fuel level is causing this hesitation.

alberg

[Don Moyer]

Alberg,

Can you tell us more about the device that allows you to see inside your
combustion chamber; including where to get them?

Thanks,

Don

[alberg]

Don

This device allows you to view the combustion process by viewing the colour of the gas explosion. In the kit there is a colour chart that indicates gas air mixture yellow for rich blue for normal and white for lean. It is available from Victoria British Ltd 1 800 255-0088 or [EMAIL="victoriabritish.com"]
search box 9-9009 (colourtune $112.44). In this kit there is a glass centred spark plug, long extention cable to connect the plug wire, a 2 piece observation tube with mirror, spark plug socket adaptor, cleaning kit, and comprehensive explanation on the test proceedure and test results.

Hope this helps

Alberg

[tenders]

$80 US from Northern Tool. (Googled "glass spark plug," result from a link from somebody asking pretty much the same question as Don, pretty far down.)

Wow, does that look like fun or what?!?

http://www.northerntool.com/webapp/wcs/stores/servlet/product_6970_200310599_200310599&issearch=16749

[alberg]

Yep same unit.