Sits for awhile then runs great...then fouls?

[Aquadzac Captain]

Seems after my Bayliner 24.5 with 350 crate runs great I will go slow (idle speed) for awhile then it starts to get rich smelling when I pick up speed past 2500 rpm...starts to boggle down. Give it a hard forward it stalls. I have to baby it run under 25oo. Then I let it sit for about 15 minutes it runs fine then the cycle starts over again? I installed a new filter and cut off switch works great. All new dis,rotor and power system with new elec pickup. Seems to be the carb to air ratio? Any old ideas or Ill take new ones before I ditch the old rochester 600 for a new one.

 

[Skipster1]

Re: Sits for awhile then runs great...then fouls?

This is a long shot but it might be worth looking into.<br />I had this problem and it turned out there was a small gas filter where the fuel tank hose connected to the fuel pump. I took that hose off and found a tiny micro-filter there.... and it was clogged with junk. <br />The junk would pile up and shut off gas flow to the engine but, when I turned it off the back pressure in the fuel lines would force the junk back into the tank.<br />So, when the engine bogged down I would pull that little filter out and clean it and re-install it. After a couple of those incidences I had all the gunk out of the tank and she ran like the devil for years.