engine and drivetrain Weber 32/36 Needle valve question

[jan1968]

I got a rebuild kit for my 32/36 carb, the original settings for the needle valve is 2.00mm but the new needle valve I got in the rebuild kit is 2.5mm.

Should I keep the old needle valve or install the new? I'm not sure how this would affect the engine performance.

Thanks in advance.

[Guest Anonymous]

I got a rebuild kit for my 32/36 carb, the original settings for the needle valve is 2.00mm but the new needle valve I got in the rebuild kit is 2.5mm. Should I keep the old needle valve or install the new? I'm not sure how this would affect the engine performance. Thanks in advance.

Original settings? Affect performance??

In a typical rebuild, you might get a needle and seat. I can't understand if you have a replacement part that is .5 millimeter taller than the previously installed part or, whether your instructions now tell you to adjust the float drop by .5 millimeter. In either case, .5 millimeter is probably not critical in any respect.

Since the needle and seat are part of the top of the carb, I would leave things with the old parts in them - especially if the needle was not leaking. If it is bad, simply take the top of the carb off and replace or readjust the float level.

I also wonder what was wrong with the carb to cause you to rebuild it? Dirt, wear, or a combination of both?

[jan1968]

Original settings? Affect performance??

In a typical rebuild, you might get a needle and seat. I can't understand if you have a replacement part that is .5 millimeter taller than the previously installed part or, whether your instructions now tell you to adjust the float drop by .5 millimeter. In either case, .5 millimeter is probably not critical in any respect.

Since the needle and seat are part of the top of the carb, I would leave things with the old parts in them - especially if the needle was not leaking. If it is bad, simply take the top of the carb off and replace or readjust the float level.

I also wonder what was wrong with the carb to cause you to rebuild it? Dirt, wear, or a combination of both?

The replacement part works with the float and as far as I know needs to be screwed all the way in.

The original needle valve had two holes opposite each other on the hex part and was stamped 2.0. The new valve has 4 smaller holes and stamped 2.5.

If I understand it correctly, if the fuel level is low in the reservoir the float will activate the needle valve and will let more fuel in. The rate at which the fuel fills up the reservoir depends on the holes. In this case I guess it hardly matters.

It was a dirty carb and was never cleaned for many, many, many years judging from the crytalized fuel in the float chamber and carb filter.

Thanks.

[Guest Anonymous]

The replacement part works with the float and as far as I know needs to be screwed all the way in. The original needle valve had two holes opposite each other on the hex part and was stamped 2.0. The new valve has 4 smaller holes and stamped 2.5.

If I understand it correctly, if the fuel level is low in the reservoir the float will activate the needle valve and will let more fuel in. The rate at which the fuel fills up the reservoir depends on the holes. In this case I guess it hardly matters.

It was a dirty carb and was never cleaned for many, many, many years judging from the crytalized fuel in the float chamber and carb filter.

Thanks.

You are spot on respecting the float controlling the level but not the rate of flow. Chances are your miserly engine's fuel requirements will never exceed the fuel pump and needle valve's combined ability to supply go go juice. Of course, anytime you mess with the needle and seat or replace the top gasket, it might be a good idea to check the float levels (very simple with gauge, ruler or caliper) even though you probably do not need to adjust a thing.

Good luck