G'day folks,
Sparker, 9P602-0058-H1 is actually the Model and Type codes for this engine - Briggs dropped actual serial numbers back in the early 1960s.

The manufacture date code is the 8-digit number stamped just after this one; format is YYMMDDxx where 'xx' is the Briggs plant location code.
E.g. if the code is '13121751', it was made on 17 Dec 2013 at plant 51.

BTW, another good download site for Briggs IPL's is http://bsintek.basco.com/MDEXResultsPages/default.aspx

As NormK says, Briggs' first plastic bodied carby was the Vacu-Jet tank mounted 'Minlon' body type. Dunno offhand exactly when they were introduced, but these are described in my 1981 vintage Briggs repair manual.

Their plastic bodied float type carbies came along relatively recently, and are a conventional design, with butterfly throttle valve. Unlike the G4/LM!

PS: The Repair Manual for this engine is HERE - 15MB PDF download. That should help with working out exactly where the spring goes.

Cheers,
Gadge

"ODK Mods can explain it to you, but they can't understand it for you..."

"Crazy can be medicated, ignorance can be educated - but there is no cure for stupid..."