av8tor1977

My Feedback: (6)

Well now, these are the answer to my prayers if they indeed work as advertised. Can't seem to find any for sale though, even though the news release for them is dated a year ago. Being the suspiicious sort myself, I am guessing that is by design so that all their retailers can get rid of their "junk" inventory first....

http://spiraldiaphragm.walbro.com

I want some!!!

AV8TOR

Truckracer

My Feedback: (19)

That might be OK but what about the pump diaphragm? Over the years using the fuel in this area, when I've had a diaphragm problem it has always been the on the pump side where the pump valves curl and don't seat well against the carb housing. Luckily, gas in this area is fairly kind to diaphragms.

Steve Percifield

My Feedback: (14)

I was told by the local Stihl 2 cycle dealer/repair station, that all 2 cycle gas engine parts have been ethanol tolerant for 10 years now..

ahicks

My Feedback: (2)

Yes, and I'd agree with them, BUT, where the stuff built now is tolerant of 10% Ethanol, there's a new spec designed to handle up to 85% ethanol. I think that might be what AV8TOR, is reading about.

The only reason I know anything about it is I just replaced a 30 year old weed eater, and something that came with that mentioned it.

av8tor1977

My Feedback: (6)

Say what they might, I have been having all kinds of diaphragm problems myself, and repairing lots and lots of machines, (hundreds), with the so called "ethanol resistant" diaphragms they sell now. I haven't had too many problems with the pump diaphragms, but I always use either the brown, or the blue plastic pump diaphragms. The black rubber pump diaphragms ARE problematic and I have encountered numerous failures with them.

I searched for quite a while on the net last night and could not find any of these new "Spiral Diaphragms" for sale. I e-mailed Walbro about them, but meanwhile if anyone sources them, please let me know.

Thanks,
AV8TOR

j_keiter

My Feedback: (21)

Walbro Spiral Diaphragm - Walbro
Jeff Sensmeier
Vice President, Marketing
Walbro, LLC.
(520)229-5657
I called over a year ago and got such a weird response I cannot remember it. Not sure why they still don't sell these. I have to replace almost every 2 years in model airplane engines. They get crispy compared to a new one. I notice engine starts to miss at 1/4 throttle or sometimes I just cannot get engine to prime. Replace regulator diaphragm with new and all problems go away.

Jason in Vacaville

PiccoLino

I basically agree with Jason. You replace the metering and the pump diaphragm and you are ready to go again for some time. A spiral diaphragm is as expensive as three or four times a rubber one and it only takes to unscrew both carburettor caps to get the job done in a matter of minutes. In the meantime you can also take a look at the filter, check the needle valve and its spring adjustment. You can rinse the carb with some white spirit too, which is something that even an eternal spiral cannot prevent from having it to be done time to time. In addition to that, I guess that something is not quite reliable in the spiral yet, otherwise after almost four years from their launching the brand new Walbro's should have them installed already. Not to mention that outside the USA, there isn't a single retailer or distributor who keeps them in stock.
Besides alcohol, to my experience, the time span between carburettor inspections/repairs depends on how often you operate your engine. If you fly at least twice a week, you should experience no carb malfunctioning for a very long while. This is due to fact that flying frequently keeps the inner parts of the carb moist of fuel which significantly slows down rubber (neoprene) aging that, otherwise, occurs very fast when exposed to air. For instance, this is commonly found in old cars restoration.

Petro companies add some 10 - 15% alcohol to gasoline in order to increase the octane number. Then they also add some green colouring chemical to ultimately call it "Green Fuel", opposed to the old toxic Lead gasoline. At least this is what happens in Europe. Therefore I buy the alcohol free low octane gasoline, (consider that for the Petro companies alcohol is more expensive than gasoline), still available at the gas stations for lawn movers and small generators, then I add 0.75% (as indicated on the label) of STP Octane Booster, which is not alcohol, and I am okay with the engine performance as it was Premium.