Author Topic: Fuel Float Level Adjustment: Clear sight plugs  (Read 681 times)

Offline Angela

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Fuel Float Level Adjustment: Clear sight plugs
« on: May 01, 2020, 07:43:41 AM »
Personally, there are few things I dislike more than trying to adjust holley 4150 fuel float levels.  I hate the fact that this must be done with the engine running and fuel spilling all over fresh engine paint, it's dangerous and has to be done anytime the carb has been rebuilt or new gaskets installed.

I have read about but never used any of the clear sight plugs (many available on summit's website).  Can anyone who's used them comment on a brand of clear sight plug that works?  I haven't seen any that don't show substantial negative feedback, so perhaps I should ignore this option. I thought I'd raise the question here and see what advice folks may have.

Thanks!

1967 eight barrel

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Re: Fuel Float Level Adjustment: Clear sight plugs
« Reply #1 on: May 01, 2020, 09:57:18 AM »
They don't have to be adjusted with the engine running.  The clear plugs are of little help either.  On my dual quad 67 GT500 I simply run the car. Shut it down and check the level. It should just weep over the threads when you remove the plug.
One of the issue that many of us where having is the aftermarket Carter pumps were putting out 7-9 PSI, which blows the needle off the seat.
Be sure to check your fuel pressure as well.

Offline J_Speegle

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Re: Fuel Float Level Adjustment: Clear sight plugs
« Reply #2 on: May 01, 2020, 07:09:21 PM »
Only tried the clear plugs once. Couldn't see the fuel level so those got tossed. Never had problems adjusting with the engine running  - just set them on the dry side then edged up till the level reached the bottom edge of the plug hole. Of course on a fresh intake you need to take precaution   with a little splash of fuel. If I was really concerned I would just hook up a cheap electric fuel pump hooked up to a fuel source and adjust them without the engine running. - of course you can still have the fuel splash or over fill issue to be prepared for. Fire extinguisher close by if there isn't already one handy
Jeff Speegle

Anything worth doing is worth doing concours ;)

Offline RoyceP

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Re: Fuel Float Level Adjustment: Clear sight plugs
« Reply #3 on: May 01, 2020, 07:13:15 PM »
Not a fan of the clear sight plugs. They tend to get coated with fuel residue and then they are useless. I start by removing the float bowls. Set the float level so the top of each float is parallel with the float bowl. Generally when you start the car, then shut it off and remove the brass plug, it's perfect.
1968 W code 427 Cougar XR-7 GTE Feb 23 Dearborn C6 / 3.50 open
1968 R code 428CJ Cougar XR-7 May 13 Dearborn C6 / 3.91 T - Lock

Offline gimpystoy

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Re: Fuel Float Level Adjustment: Clear sight plugs
« Reply #4 on: May 02, 2020, 02:53:05 PM »
 Acword of   experience.   Those sight plugs are for use to adjust, then put  brass plugs back.. Do NOT leave in ! they will disintegrate over time. That was my experience w  the  Holley   sight plugs.
Gimpy
67 C code Metuchen, May "67" build 289 C4