MacGregorSailors.com

My fuel primer bulbs are lasting about 3 to 6 months.
They rot out and start spraying me and allowing air into the line.
Regular replacement seems the best answer.
The bulb that came with mine lasted years, so what gives?
What bulbs have you guys been using?
Any last for reasonable times?

My original bulb is still serviceable. 17 years old and still going. I don't know what BWY used when they installed it.

Last year I replaced my entire fuel line and added this one. It seems to be hold up well.

https://www.amazon.com/dp/B07H2X1BTB?re ... tle_6&th=1

tks, will try it.

I haven't had this problem (yet) but I think ethanol in gasoline can ruin gas lines. I had a chainsaw that had its fuel lines and primer bulb go to mush likely due to ethanol and me forgetting to add an appropriate fuel treatment. Perhaps the same is true for marine fuel lines and components? I'd like to think the manufacturers would have rolled with the times and created more resilient fuel system components though.

Duncan

PS - having lots of fun destroying the Christmas lights on the top of the webpage....very distracting to getting real things done

45Plus+ wrote: ↑Tue Dec 09, 2025 3:29 pm
PS - having lots of fun destroying the Christmas lights on the top of the webpage....very distracting to getting real things done

It's somewhat cathartic isn't it?

Good point on the Ethanol. I had a fuel line literally crumble first year of use. It may have been ethanol that did it.
NOW I ensure to use pure ethanol free gas. There are other reasons to avoid ethanol in boats. Attracts water and our boats are floating in water.

I think you just got a bad bulb. I don't think I've every had less than 15 years on a fuel line or bulb.

3 - 6 months sounds off. I replace mine every 5 years (just to be safe). Never actually had a problem.

leefrankpierce wrote: ↑Mon Dec 08, 2025 11:08 am My fuel primer bulbs are lasting about 3 to 6 months.
They rot out and start spraying me and allowing air into the line.
Regular replacement seems the best answer.
The bulb that came with mine lasted years, so what gives?
What bulbs have you guys been using?
Any last for reasonable times?

I agree, not normal, which is why I am asking here.
A 3 month old bulb just sprayed me with fuel after my engines float bowl filled.
I have been adding SeaFoam to my fuel, but that seems such a normal thing.
Only other thing is, I run my carbs empty before leaving the boat by unplugging the line from the tank while engine is running.
This collapses the bulb, but then I release the suction by pushing on the release valve before I leave.

Ethanol can harm rubber
DOES ETHANOL HARM RUBBER?
Ethanol can harm rubber, particularly natural rubber, by causing swelling, softening, and loss of elasticity. The extent of damage depends on the concentration of ethanol and the duration of exposure. Higher concentrations and prolonged exposure increase the risk of degradation. Ethanol acts as a solvent, breaking down the polymer chains in rubber, leading to reduced mechanical properties. Synthetic rubbers like EPDM and Viton are more resistant to ethanol damage. It is advisable to avoid using alcohol-based products on rubber components unless specifically designed for compatibility.
cyalcohol.com
+3
Lee

Forgot to mention I am only running E-Free fuel, 2 stroke, premixed.

You must have gotten a bad fuel bulb or supplier. I had a hose deteriorate the first time I installed it. I'm certain it was a bad/old hose. Perhaps sitting on a shelf dry rotting for a decade. Of course ethanol will not help, but a quality hose and primer should stand up to it.

Replace it with a some quality components and I bet you will okay.

I doubt Seafoam would do any damage. As far as I understand, it's made from petroleum distillates and won't damage fuel systems. I've stopped using Seafoam due to its high price, and some research raises doubts about its benefits.

I also have serious doubts about Stabil. It has an expiration date and some testing has shown it to be less than advertised. Stabil apparently does NOTHING to combat water in the fuel which is probably the biggest failure point in our engines.

I watch too many Youtube videos and found this channel where she talks about Stabil and why she uses Ethanol Shield. So now I'm a convert and using Ethanol Shield.

Russ,

In the first test she added water to the chemicals in the vials. In the second test, she added the chemical to the water. By that action alone there is mixture. She did not wait to see any separation. I would prefer to see an apples to apples test. The stuff may work, but she did not prove it. Unless I’m missing something.

Interesting. That's the "short" version of her video. The last test she did shake it.

Here's the LONG version of the test.

Obviously a better product.

Last I checked Seafoam is between 10% and 20% isopropyl alcohol. It's effects on fuel lines is different than those caused by ethanol but neither is good for rubber. It's possible that is what aged your primer bulb prematurely.