Looking for suggestions on what fuel primer bulb fits 7.5mm ID fuel hose

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Emil Wojcik
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Looking for suggestions on what fuel primer bulb fits 7.5mm ID fuel hose

#1 Post by Emil Wojcik »

I'm trying to find a fuel primer bulb on Amazon that will fit with 7.5mm ID fuel hoses for my '64 C. The closest I can find is 5/16", which is just about 8mm. Will this work if I use hose clamps or is there a better option?

This one is highly rated but don't want to order something that's not going to work.

https://www.amazon.com/gp/product/B0054 ... 0DER&psc=1
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Re: Looking for suggestions on what fuel primer bulb fits 7.5mm ID fuel hose

#2 Post by Greg Bryan »

I think 5/16 will be fine. The fittings on the fuel pump etc are 8mm. Most people use 7 mm hose and it seems to work although 7.5mm was the original size
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Re: Looking for suggestions on what fuel primer bulb fits 7.5mm ID fuel hose

#3 Post by John Brooks »

That is what I have used in the past, get good clamps for the hose. Mind the arrow on the bulb, go toward the pump.
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Re: Looking for suggestions on what fuel primer bulb fits 7.5mm ID fuel hose

#4 Post by Steve Turino »

So I have a couple of questions about the priming bulbs. Sounds like John is saying the arrow on the bulb points toward the fuel pump not the direction of flow? Is that right? Or is this installed before the stock fuel pump.
Also how do you know how many pumps to give it, can you flood the carbs? I am considering either this simple option or the electric fuel pump behind passenger foot board.
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Re: Looking for suggestions on what fuel primer bulb fits 7.5mm ID fuel hose

#5 Post by Martin Benade »

Arrow is direction of flow. After several squeezes it gets harder, then the carbs are full.
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Emil Wojcik
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Re: Looking for suggestions on what fuel primer bulb fits 7.5mm ID fuel hose

#6 Post by Emil Wojcik »

Thanks to everyone for the replies, I'm ordering today.

I've seen some bulbs installed between the fuel tank and pump and some between the pump and carbs, as shown in the photos below (Don't remember who's photos these are but I believe they're member's cars). Which works best?
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Re: Looking for suggestions on what fuel primer bulb fits 7.5mm ID fuel hose

#7 Post by Steve Douglas »

Be very careful in your choice of bulb pumps, as I have recently seen two that deteriorated with ethanol gas and were leaking. The good ones used for outboard motors are more expensive but list as ethanol proof. The cheap ones sold on Amazon, Harbor Freight and Walmart don't last but a few months.

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Emil Wojcik
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Re: Looking for suggestions on what fuel primer bulb fits 7.5mm ID fuel hose

#8 Post by Emil Wojcik »

Thanks, Steve. The one I'm planning on buying is from Attwood Marine, which the specs list as "Compatible with Ethanol blended fuels"
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Re: Looking for suggestions on what fuel primer bulb fits 7.5mm ID fuel hose

#9 Post by Wes Bender »

I would mount the bulb between the tank and the pump. In normal outboard motor use, they see suction while the motor is running. They are probably designed for that rather than constant pressure. Just my $.02. (I only have experience with these on outboards and am using an electric pump on the Porsche.)
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Emil Wojcik
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Re: Looking for suggestions on what fuel primer bulb fits 7.5mm ID fuel hose

#10 Post by Emil Wojcik »

Thanks, Wes, that makes sense.
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Re: Looking for suggestions on what fuel primer bulb fits 7.5mm ID fuel hose

#11 Post by Brian R Adams »

I got a squeeze bulb at the local West Marine store, and installed as Emil's photo shows, but could never get any draw there. Someone opined it was because I have an 'A' model and fuel cannot be forced by vacuum through the fuel pump. The implication was that the 'C' pump would cooperate. Seemed odd to me, but I removed the bulb and never followed up.
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Re: Looking for suggestions on what fuel primer bulb fits 7.5mm ID fuel hose

#12 Post by Wes Bender »

Did you install it before the pump, Brian? He shows both locations in the two photos.
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Re: Looking for suggestions on what fuel primer bulb fits 7.5mm ID fuel hose

#13 Post by Brian R Adams »

Wes Bender wrote: Mon Mar 20, 2023 6:59 pm Did you install it before the pump, Brian? He shows both locations in the two photos.
Glad you asked, I used the wrong terms. I installed it before the pump, trying to push (not draw) fuel through it thence to the carbs. I didn't want to section the 'T' hardline between the pump and carbs, so never tried that.
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Re: Looking for suggestions on what fuel primer bulb fits 7.5mm ID fuel hose

#14 Post by Steve Turino »

I thought I had seen the bulbs only installed after the fuel pump hence my confusion on John's comment. I know the arrow indicates flow direction. At any rate, installing the bulb between the tank and pump makes sense.
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Re: Looking for suggestions on what fuel primer bulb fits 7.5mm ID fuel hose

#15 Post by Martin Benade »

Brian, that’s one of the typical locations to add the bulb. It should work fine regardless of which fuel pump you have, as long as the valves in it aren’t stuck.
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