After winter storage my 230 sl is not running as it should. It sounds like it's not running on all six cylinders - but it is. The spark plug cables, condenser, distributor cap, condensator and rotor have now been replaced. The cold start valve has been removed and tested to ensure it clicks as it should when directly powered. It sounds a bit like it’s running with the choke on, but it’s not producing black smoke as it would if the mixture were too rich. It had the same issue after the last winter storage, but it resolved itself after a few kilometers. There’s new V-power in the tank. The return hose to the tank has been blown through. Any suggestions?