Setting float height.

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Steve6
Posts: 16
Joined: Wed Apr 23, 2014 4:18 pm

Setting float height.

Post by Steve6 » Sun Apr 26, 2020 4:30 pm

Hello All, I have been struggling to get my 1948 Rover 75 to pick up cleanly from idle. I thought i had found the problem when I discovered the fuel level in the carburretor bowl was 25 mm below the upper edge. The only information I can find indicates 12mm for most Solex but I can't find a value specific for the 30 PAAI carb. Can anybody confirm the figure please? The float is marked 20g and the needle valve has one fibre washer beneath it. No matter what I do, I cannot seem to raise the fuel level much before the float hits the gasket above it, and then of course it floods. What am I doing wrong? Thanks for any advice.

Ray
Posts: 20
Joined: Sat Feb 22, 2020 12:30 pm

Re: Setting float height.

Post by Ray » Fri May 15, 2020 11:19 am

Hi Steve,
I have a similar problem with my P3 in that it won't pick up from idle.
I have posted a reply to one of your earlier posts in which you suspected the accelerator pump.
You mentioned that you had invested in a replacement carb and I have asked if you have any parts you are willing to sell.
If it's of any help I can take the top off my carb and measure the distance from top of float bowl to fuel level.
Please let me know if you have already found a solution.
Regards,
Ray Lilly

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luli
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Re: Setting float height.

Post by luli » Fri May 15, 2020 12:58 pm

The fuel level should be equal to the center of the spray column in the venturi . Have you checked that it is so?
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Ray
Posts: 20
Joined: Sat Feb 22, 2020 12:30 pm

Re: Setting float height.

Post by Ray » Tue Jun 09, 2020 2:46 pm

The float bowl is full to the brim but the float valve is working OK (new)
I assume the float bowl is being fed by another path.
Any idea how that can happen ?
Regards,
Ray

Ray
Posts: 20
Joined: Sat Feb 22, 2020 12:30 pm

Re: Setting float height.

Post by Ray » Mon Jun 15, 2020 10:06 am

Hi Luli,
I have measured the distance to the middle of the spray column from the top of the float bowl. It was 0.27 inch.
Does that sound about right to you ?
If it does sound right, then my float level must be wrong because it leaves the fuel level at 0.71 inch from the top of the float bowl.
That is, 0.44 inch lower than the middle of the spray column.
If I have done this right that means my fuel level being low would probably cause a weak mixture but in fact it is too rich even with the volume control screws being almost fully screwed in.
Have I done this right. Please advise.
Regards, Ray Lilly

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