l just purchased w/o warranty a 2007 Regal destiny 2120 that started and ran in my driveway. Put in water with 40 gallons new gas and tries to start, but wo not at idle. Started after repeated attempts, but had to put in gear and increse RPM to keep running. Any help please. Plugs, fuel system, etc. Is there a way to increase idle speed. There seems to be no adjustments on carb.

clean injectops bleed fuel pump well

Many possibilities here. Probably varnish on the carb jets from being stored too long or with unstabilized fuel. You can spray the carb out with Gumout or any good carb cleaner & see if that does the trick. Recommend u put a carb cleaner in the fuel & replace the fuel filter. When storing, particularly if ur gas has alcohol in it, use the Stabil marine formula.

If cleaning this out does not do it, does the engine operate fine at speed & loaded? If so, it is likely the idle jet & u will have to remove it & clean it (provided filters & fuel pump r ok, but the fact that it runs fine at speed, loaded would tend to eliminate them as issues).

There must be a throttle stop screw,but if you cannot find it try this,
Where the throttle cable enters the Carb.you will find an ajustment to the length of the outer cable,adjust this and it will stop the throttle from
closing right down.
Good Luck.

Your engine is computer controlled and you should take it to a trained Volvo mechanic. He can run a simple diagnosis and tell you what is wrong quickly, but first get an owners manuel. you might not be starting it correctly.