1971 280 SL Does not go over 80 mph

[miamipagoda]

my 280 SL has been sitting in a storage for couple of years, i have turn it on regularly and drove it on very short distances with no problem
I took it on the highway today and when I get to 80 mph, the car start stalling and does not want to push higher
any idea what the problem might be? is it a fuel issue because its been sitting? or the spark plugs might need to be changed?
thank you
Z

[ja17]

Hello,

The main fuel filter should be checked first.  If it is dirty you may also have clogged fuel screen issues in the electric fuel pump and fuel tank.  Also, replace the spark plugs (cheap and easy).