Holley Carb sight plugs

[ceslaw]

Simple question:

Replaced the two plugs on the side of the float bowls on the Holley carb with the clear plastic sight plugs to simplify float adjustment. The floats are now adjusted. Is it okay to leave them in permanently or must they be removed and the metal plugs replaced? I am not sure if prolonged exposure of those plastic plugs to heat and fuel is appropriate.

[4into4]

You're correct. They're intended to make float adjustment easier, then replaced with the metal plugs once your level is good. Over time, they can break/leak.

[wtm442]

They were brought to market so Holley could make more money. They are much more prone to leaks and resultant fires. Plus, the adjustment of the float level will NOT be as accurate as if you were using the brass screws.

[danc30]

QFT carbs come with the clear sight plugs installed. Mine are fine and make it much easier to see and adjust.

No issues yet.

[ceslaw]

Nice discussion on adjusting the floats. That is exactly how I did it. Then put the plastic plugs in to make it easier to spot check it in the future.

But the point is well taken. Putting the screws back in is cheap insurance against a plastic failure.

Thanks for the good info.

Originally Posted by wtm442

They were brought to market so Holley could make more money. They are much more prone to leaks and resultant fires. Plus, the adjustment of the float level will NOT be as accurate as if you were using the brass screws.

Adjusting primary float level
http://clubcobra.com/forums/showpost...0&postcount=36

Adjusting secondary float level
http://clubcobra.com/forums/showpost...0&postcount=37

[wtm442]

Something really screwy with hy last post. No matter what, it only would link to ONE post and not two.

Check out page 3 of this post for a detailed description on float adjustments.

http://clubcobra.com/forums/showthre...240#post853240

[Rick Parker]

The sight plugs being discussed are those marketed by some vendors that screw into the float bowls in lieu of the OEM Brass Plugs. The clear plastic plugs seem to get cloudy with any age and can easily break off the treaded section when being tightened. They are intended to only be used temporarily and removed after the float levels are verified and adjusted.

[Ron61]

Rick is correct. I used them for a while and then went back to the brass plugs. It was not so much work as putting the plastic ones in and setting the float level and then taking them out and checking it and putting the brass ones back in. I never had any leaks or cloudy problems with mine but they were never in the carb for long. Now I just use the brass plugs.

Ron

[danc30]

I agree that if you have a Holley, use the glass to set the float and put the brass back in. BUT, if you have a QFT, the float level must be around halfway up due to their emulsion hole set up. There is no way you can set the float without glass plugs. Besides, they come with clear siteplugs already installed.

[sharpe 1]

Read the instructions that come with the carb.I believe it tells you to use the clear plug to set float level, and then to remove them and install the brass plugs.

[Michael C Henry]

Are ther actually glass version of those plugs? I tried the Plastic plugs and they seemed to swell in the threads over a short period of time.

[Rick Parker]

No removable glass ones, but a few models of Holleys have a larger glass or plastic port, (about the size of a Nickel) allowing the fuel level to be viewed. The "Window" is built into the side of each of the float bowls and is not normally intended to be removed. On carbs without the sight plugs, the fuel level is correct when with the brass plugs are removed, the fuel just ever so slightly dribbles out, right at the bottom of the threads.

[rodneym]

I was going to post a new thread but thought I resurrect this one...

Last night I screwed in some Holley Fuel Bowl Sight Plugs, finger tight. About 10 mins later I decided to give them another crank because I didn't want fuel spilling on the intake. I go back to the engine and see one of the plastic 'heads' had popped off, leaving the threads inside! I try to unscrew the other and it popped off just touching it! I tried to super glue the heads back on and unscrew but I only managed to get a half turn out of one. I tried a couple of other methods and got nowhere. I had to take out the carb and bowls, put tape behind the threaded hole so pieces wouldn't get inside, and dig out the remnants. Love having to spend time on something that went wrong, only hoping you never did it to begin with.
I went online and read similar stories. Don't know if the plastic to too low grade, or maybe the threads of the bowls weren't very clean 'that far in', but at any rate, be VERY careful or don't bother with those clear plugs, any brand. The factory installed windows are a different story.
Live and learn I guess. I'll have to do it the old fashioned way.

[mreid]

For many, many years we adjusted Holleys without these cursed plastic demons! I say don't waste your money. The float level is very easy to adjust without them as it has been done since the beginning...

[WardL]

I bought my Cobra used 16 months ago (seems like yesterd'y) and it came with cloudy rubbery bowl plugs. They seemed to weep gas a little but because I didn't know what they were I left them alone. Last week I was trying to adjust the float and since they were cloudy I pulled them out to see what was going on. About the 3rd time I pulled one out it broke in half as described above. I ordered new plastic and brass plugs before reading this thread! I suppose now I have to pull off the bowl and poke out the plastic piece left in the carb! Thanks for the threads on float adjustments. I need them!

[JBCOBRA]

With the crazy additives in gas now, had some of the plastic plugs melt right off the carb!