didn't give much to go on..year?..model no.?..hp?..but, go to the Top Secret Files at the beginning of the Forum ..scroll down to Fuel Primer and click on the file containing a pic..is this what you're referring to?
The red part you need may be part of the fuel primer. It has been updated to part number 175158. Called a maintenance valve. This later version has been updated with the Schrader valve on it.
