3607 Fuel Probs

Follow the fuel line from the carberator or the fuel injection, it cannot be far and many times is mounted on the engine. If you are not capable of finding it without help, I would highly recommend paying a pro to change it. A Gas leak on a gas inboard boat is nothing to play with and can be very deadly. There also may be 2 fuel filters, a primary and a secondary.

since i have a carver with crusader 454 xli i will try and help. didnt know what year your boat is mine is a 405 1997 throttle body injection. if similiar read on. as the gas line comes to the engine there is a black round disc (oberg filter) it has a bolt running through the middle of it. there is a screen inside of it that if you take the nut off the filter housing will seperate and you can remove and wash out (put someting under it to catch the gas that will come out as you loosen the nut) with soap and water etc. check the screen for any tears etc and be careful cleaning it so you dont damage it. reasseble it then next there will be a water seperator its in a gold housing or similiar and will have a nut on the bottom (you can open and drain this housing)fuel lines in and out of it on top. it unscrews and there is filter inside. you will have to replace this no cleaning out except any big stuff you can see. the filter if like mine is racor 110A using a rt11 filter inside. should be some info on the outside saying what model or make it is. next at the throttle body there is metal cannister filter mounted horizontally with metal fuel lines with nuts securing the lines to it running out of each end. this part is crusader filter 23250 or sierra 18-7976. the fuel will be under some pressure so you will see a valve like a air fitting right beside it to push and relieve the pressure or if not place a rag under and around it when you undo one side slowly, then the pressure will release and you wont get sprayed with gas. you will have to change it no cleaning it either.
verify what you see and if its not like this there are plenty of manuals online or if you have the original manual for the boat the crusader manual should be in there hopefully this helps. if not post some more info on your engines so we can help. if nothing else you could open the oberg filter and see what it looks like while your waiting to purchase the other filters. once you have replaced everything make a couple of inspections while running the engines and after to verify no fuel leaks. good luck

to help find it the oberg filter housing looks like this
http://www.amazon.com/Oberg-Filters-4028U-Billet-Micron/dp/B00CJ3Z40W

the screen that you clean looks like this
http://www.circletracksupply.com/images/P/OBERG SCREEN-01.JPG

Yes, change fuel filter first; easy and quick. If that doesn't solve the problem, which sounds almost exactly the same problem I had when I bought our boat 4 years ago, it could be a distributor going bad.

Idle was fine, then we'd power up ok, but then would just start sputtering and total loss of power, until we throttled down, and then up again. Eventually it just failed altogether and needed to be replaced; problem solved.