The linkage...

the transmission gear selector should be solid... not a cable, IIRC. You most likely have some worn bushings in the assembly, or are you talking about the cable that actuates the gear selector quadrant on the dash?

The twin Zenith carb set-up on the engine should be equipped with a "dash-pot" which is designed to stabilize the idle speed, especially when the car is put in gear; yours is most likely incorrectly adjusted, or has failed.

A 250S is a lot of car for $400! Good luck on your purchase, but be prepared to DIY a lot, as bringing these cars to the dealer [if you can find one that will work on it, most will discourage you from bringing the car there] can get really expensive, really fast.

Additionally, I should mention that the car appears to be a European version, not an official import. Your profile does not indicate a location [you might want to complete this, as your location can prove helpful in advice given...] Usually, these have rust lurking in hidden, and sometimes not so hidden, places... Get the car up on a lift and check for this, as rust repairs can get expensive as well.


JR

 

my location is spokane, wa. there is some rust around the headlights and around the tires.

 

It's so simple, like my 220S. Buy the car and repair it. You will really enjoy driving it.