What Life Do You Get From Your Diaphragms?

[Ray from Indiana]

I'm curious as to what other people see with regard to diaphragm life in years, not miles before you see degradation.
Then what type degradation do you see - stretched diaphragm, hole, tear?

In your reply please tell us what % ethanol is in your typical fuel too.

[ME 109]

I do mine about every 5 years. 98 RON fuel
What's ethanol?

[Ray from Indiana]

I appear to be getting about 3 years before diaphragms get stretched out making cable balancing for 3500 rpm next to impossible for repeatability.

I typically run what's available near me, 93 octane ,(RON+MON)/2, with 10% ethanol....that's what we have near me and I'm in the Chicago fuel market area.

[Jean]

Three to 5 years depending on usage.
When the acceleration goes sluggish, I figure it's TIME to replace.
This is before you see a tear or other obvious damage.

[Ray from Indiana]

Jean

Do you find your diaphragms to be stretched or distorted when you change them out? That's what I'm seeing even though acceleration wasn't sluggish I was getting vibrations from imbalance. Never have had a tear or pin hole.

I've seen the same thing on a lawn mower with Briggs & Stratton engine with a diaphragm...had to change it once per year when it started running like crap I knew it was time. I blamed it on ethanol vs. the diaphragm material.

I wonder if the Delrin diaphragms as sold by Motobins would be a better material
Sorry, its Hydrin, not Delrin

[jtoml]

I changed mine after 30 years (preventative maintenance....), and they were in good condition! I live in a dry and non-corrosive climate, and no ethanol.

[Ken in Oklahoma]

I changed mine after 30 years (preventative maintenance....), and they were in good condition! I live in a dry and non-corrosive climate, and no ethanol.

And I have never had to change a diaphragm that wasn't years old.

Ken

[Jean]

Ray, stretched could describe them. They seem a bit floppy compared to the new ones.
I've used the term "dead", before, to describe them. The new ones seem to be stiffer...

[Zombie Master]

She got pregnant. I don't trust them.

[ME 109]

She got pregnant. I don't trust them.

ZM, in your case 'human' would have been a more appropriate answer to the op's question.