The plastic intake mainfold tube going to the carburetor on my Murray 4.5 gas push mower is broken which is probably why it won't stay running after priming. I was taking the carburetor off to have the O rings and gasket replaced because of the ethenol they add to the gas. Can this be replaced?? I now have Sta-Bil Marine fuel additive to add to the gas to stop the corrosion the ethanol causes to engines.

