Tech Tip: Holley Clear Sight Plugs

[Silver68RT]

If you tighten them up and leave them in, and it gets a little chilly overnight, the heads will pop off. Then you'll be pulling your carbs off to remove the float bowls and dig out the threaded portion that's now stuck in the hole.

They didn't mention that on the instructions, so I thought I'd share it.

[squirrel]

YOu don't need to let them get chilly, they do it in the summer too. Thanks for the tip, you're a little over a year late for me.

[milner351]

perhaps that's why the barry grant and others have a clear sight glass held in with an E clip, no threads.

Sorry to hear of the problems Doug - bummer.

[Silver68RT]

Thanks, this thing is just fighting me every step of the way.

Besides the sight plugs this weekend I've had trouble with the starter, can't get the clutch inspection plate off, and the trans appears to have no gear oil in it. Pulled the plug and stuck my finger in, can't feel anything as far down as I could reach. I really can't trust that anything was done right on this car.

Haven't gotten to the compression test yet.

[antmnte]

Mine started to leak before that happened .Put the brass screw back in. I guess its good temporarly but I wouldnt leave em in there.

[Silver68RT]

Mine started to leak before that happened .Put the brass screw back in. I guess its good temporarly but I wouldnt leave em in there.

Yeah, I put them in yesterday because I wanted to set the floats, then it wouldn't start. I left them in overnight because I hadn't fixed the starter problem yet. Got the starter working this morning, then noticed the head of one of the plugs on the floor while I was under the car. 3 of 4 snapped off overnight, and they've only been on the car 1 day.

[CDMBill]

I never had that happen unless it was when I hamfisted one and broke it off. I was taking it off becuase it had become cloudy as they didn't like oxygenated Cali pump gas. They always became cloudy. Back to brass.

[anotheridiot]

are they recommended to be left on or just used as you are adjusting your level?

[squirrel]

holleys instructions say to remove them after adjusting the float level. If you can get them to last that long you're doing good

[Beagle]

holleys instructions say to remove them after adjusting the float level. If you can get them to last that long you're doing good

Dayyum! That's not much of a testimony - wonder if the Holley boys know this?

[Silver68RT]

I've got a 750 Speed Demon on my '69 Dart, it's got sight windows and they're still crystal clear after 10 years. It's a neat feature, but clearly getting the Holley sight plugs was a waste of time and money.

[milner351]

I generally set the float level with the bowls off and inverted - to the measurement in the rebuild kit - then I don't mess with them.... but that sight on the demon bowls is sweet - never have to wonder if the float level is right.

[oj]

The way around breaking the head off is to retap the float bowl to coarse thread. If you look at the original holley screw yu will see it is national extra-fine thread, the clear plastic sight plugs are coarse thread. Run a tap thru there and finger tighten to seat the 'o' ring and you're done.
fwiw, i don't use them at all. I upgrade the bowl to the glass lens or leave the brass screw in place.