Motor Problems

Crusadar 350 , 270 HP I have had both carbs rebuilt, fuel pumps changed, filters replaced, gas tank emptied. one day the boat runs fine, the nest day one engine will loss power ,back fire etc. Sometimes both engines will act up. Any ideas appreciated.

How empty was that gas tank? I suspect they didn't get the crud on the bottom out, and the stuff that gasahol creates will not burn.

Jeff

Sounds like twin engines with a single tank (shared) based on your description. In addition to Jeff's thought (tank emptied or emptied and cleaned out?), I'd add checking the vent line for restrictions, the infamous anti-syphon valves, and checking the filler cap o-ring. You may also want to take a sample of the fuel being used to make sure you still have good fuel going into those clean (new) components.

Yes, Ethanol is the root of all evel in the most engines and if it sits in the tank, it will separate. The refineries blend it in line into the tanker trucks for that reason. You are buying crap for your boat if the engines are older like my 1995 Crusaders. I had similiar problems with starting after running for a little while and letting them sit for an hour. Seems the heat in the bilge caused phase separation or something technical like that. Had a similiar experience in a 2001 Honda Accord the wife drives last summer! And those fuel line check valves collect more crap faster than you can imagine, so pull them out and clean them up! They caused a lot of power loss issues due to fuel delivery on my 454's.

Here's what that non-burning crud that collects in the tank (thanks to ethanol gas) looks like. The white "stuff" flows right through filters but won't burn, and no know additive will make it. The only solution is to get it out of your tanks.

Jeff