Echo PB-500T won’t start properly

[Cfs]

I did think it was odd that the lever and spring were not included. I reused the old ones… not ideal. I was thinking that I had read somewhere that the synthetic pump diaphragms, like the electric blue colored one were an upgraded version and replaced earlier styles if they match are the pattern/configuration as the one you are replacing. I am going to try to research it at Walbro’s website

 

[Cfs]

Not to answer my own questions. But I just watched a YouTube video on the subject of pump diaphragm materials. I found it searching in my YouTube app
‘Walbro Carburetor Diaphragms’. The guy who did the video identified 3 types.

Rubberized which are black and rubbery, Acetone which are the stiff shiny dark blue and other colors, and Teflon which is an off white shade and appears to have a textile/fibery texture. He explains that the rubberized are the least resistant to ethanol…even though Walbro says all 3 types function fine with up to 10% ethanol. I won’t try to cover all the points he makes in the video but I thought everyone who is interested in this subject might like to view it for themselves. I would be interested to hear the reactions of the experienced members of this forum. I would try to copy a link to it but I am an old fart somewhat tech-challenged He said that they have different characteristics as pertaining to how well the pump, how oil rich of mix they handle and ethanol resistance and temperature performance
CFS

 

[StarTech]

I believe you mean Acetate not Acetone as Acetone is an liquid (solvent) used for all things the removal of finger nail polish. Also makes a good penetrating fluid when mixed transmission fluid.

 

[Cfs]

Yes I misspoke it is acetate. Thanks