Rough idle

[Theoneandonlyjohn]

I've had my Ingersoll 648 for as long as I can remember. I think my grandfather bought it, left it to my father and now I'm the one struggling with this heep of junk. To be fair, it's been serving its purpose excellently, but recently I've noticed some rough idle. Before I start tearing it apart, I could use some opinions. Shold I start with the carb before diving deeper?

 

[Christian Dior]

Yeah. I guess it's best to start with the carb and check for gunk or varnish buildup. Also peek at the fuel filter and lines while you're in there. It's always best to rule out the easy stuff first.

 

[Nikky19]

If it's still running decent under load, chasing a perfect idle is a waste of time, these old 648s weren't built for smooth idles...they were built to work. People obsess over carb tweaks when 90% of issues are ignition-related anyway.

 

[Christian Dior]

@Nikky19 makes a good point, but maybe it woukd be better to still give the carb a quick once-over. It's cheap insurance before you start chasing ignition gremlins.