Float level woes

[Tennessee Tim]

New member, so please be gentle...I tried to search to the best of my ability, but did not find answers.

I have a set of new-style "Made in Spain" IDAs for my 331 SBF. I am trying to get the float levels set properly, and I have some questions. I have fabricated the tools needed in accordance with the instructions I have found in several places. The first tool is the needle and seat gauge. As per the instructions, it is 25mm. My first quandary stems from the fact that none of my needle and seat assemblies are really close to the 25mm. Three of them are in the neighborhood of 24.5mm, and one is about 26. When I bought the carbs, I also bought two spare needle and seats, both of which are closer to 26mm. It almost seems as though there are two different types - the needle on three of them seems to be about a millimeter and a half longer than on the other three. However, I can find no markings that would seem to indicate two different parts. All 6 are 200s. Is this normal variation? This doesn't seem likely to me, since I have 6 needle and floats, with three having nearly identical measurements, and the other three having three identical, but completely different measurements. If this were simple manufacturing variations, I would expect to see more variability. At any rate, I don't see how I could possibly bring the 26mm parts down into spec, unless I eliminate the gasket entirely, and I'm pretty sure I don't want to do that.

Secondly, the tang on the floats are all embossed with "25.5". This is curious to me, as I would think that this is a measurement of some sort, or would at least have some meaning, but it does not correspond with any of the standard, widely published measurements. I am starting to become concerned that all of the measurements I have seen have been related to the old style IDAs, and perhaps the new styles require a different setup for float level. If the "25.5" were to correspond to the needle and seat height, it would make sense, since that is achievable with some tweaking with the two lengths of needle and seat I have.

Finally, given the uncertainty that I now have with setting the float level on these carbs, is there another, independent way confirm that the float level is correct? I.e., can I fill the bowls and check the actual fuel level against some criteria?

Any help with this would be greatly appreciated.

Tim

[barry950]

Check out this website.
www.biekerengineering.com
Phone 541-955-9777
They make a visible sight gauge that screws into the float chamber drain plug hole. Ive used it on 2 of our cars and it works great.

[Earl J]

Hi Tim,

I can appreciate your creativity in designing and building your own float adjustment tool, But there is an easier way. Without having to re-design the wheel so to speak, Gene Berg offers a tool (#GB552) which takes all the guess work out of setting float levels for the 48 IDA.

Float level is critical to the 48 IDA, get this wrong and you will hate Webers!

Anyway, I use this tool exclusively to set float levels on my carbs. No guess work. I have a set of early serial numbered carbs from approximately 1966 stamped 48IDA with serial #’s 931, 935, 1031 and 1035 which they have not been modified for/with the 3rd progression holes.

Back to float adjustments, I also use these 2 spacers and nuts (in the photos) due to the studs where I mount the needle/seat to the plate then attach it to the carb. Float levels are measured by inverting (holding and turning the carb upside down) then measuring how far the float hangs down once it rests against the needle/seat assembly. All I do is adjust/bend the tab on the float to achieve the required 5.5 to 6.0 spec (2nd part of the tool, see pic) so when I hold the other tool against the body I’m within tolerance per the Gene Berg instructions. Personally, the tool is a vital investment and not too expensive for what it does, it's easy to use too. I still have hair on my head!

Happy Tuning,
~Earl J

ps. By the way Welcome to the CC forum!

[Tennessee Tim]

Thanks, guys.

Barry - that link does not work for me and hasn't for a while. I had bookmarked it several months ago with the intent of getting the gauge when I got the motor put together, but it looks like I waited too long.

Earl - I like the Berg approach of fixing the needle and seat in place to measure the float height. One of the tools I made is to function as 98014.200 in this diagram:



It seems that this will only work if the needle and seat are at a fairly precise depth. The Berg approach seems like it is adjusting the float level directly off of the needle and seat as opposed to using an indirect intermediate measurement. As a result, differences in needle and seat height would not matter.I think I'll order a set of those tools.

Thanks again.

Tim

[Rick Parker]

The tool Barry suggests is the same type as used by Porshe techs on the IDA 3c, Zeneth & Solex 3 bbl carbs. It measures the actual level inside the bowl and uses a marked glass tube that attaches in place of the fuel bowl drain plug.The issue with using it with the 48 IDA is that the float level cannot be adjusted without removing the carb top, unlike the 3bbl which has the needle & seat which can be accessed without disassembly. The Gene Berg tool is relatively inexpensive and works well. Regardless of how it is achieved, the actual level in the float bowl is the item to focus on. A very important part to improvise is item #98013.800 It is made from a piece of Clock Spring (think clock repair shop) it holds the float while using the Gene Berg gauge and measuring the tang dimension.

[Dwight]

Tim, welcome to CC

there are 63 members in the Chattanooga Cobra Club. Several in the Nashville area.
And we have about thirty in North Ala. Florence to Huntsville.

Hope to see you at a show or one of the Cobra activities .

Dwight
North Alabama Cobra Club

[dallas_]

Originally Posted by Earl J

Without having to re-design the wheel so to speak, Gene Berg offers a tool (#GB552) which takes all the guess work out of setting float levels for the 48 IDA.

Thanks for the link. I just ordered one of those too.