10 Meter 454 losing power

[Lumpy]

Guys,
I've got a 10 Meter Express with Twin 454/350 Crusaders. In short when cruising at 3K the Starboard engine starts to lose power to the point where I have to take her off plain. She continues to run nicely at 1500 rpms. I believe it is a fuel issue but wanted to see if anyone has some insight on this. I've had this engine rebuilt down to having the crank checked & polished. It still has points which were just replaced, new fuel pump, wires, cap & rotor 1 yr old. The fuel line isn't completely metal. Coming off the fuel pump about 3 inches it goes to a hose for about 3 inches then back to a metal line. Would the vacuum cause the hose to collapse at speed? Any thoughts would be greatly appreciated.

Thx
Chris

[BobCT]

Chris,

A anti-siphon valve that's clogged will do that. Have you tried the crossover valve to see if the problem is with both tanks/sides? That was my issue and exactly as you describe.

Bob

[yorklyn]

I agree with Bob. check the siphon valve.
Is your fuel good?

[Lumpy]

I'll check the anti-siphon line. I only have one tank and the port isn't showing any of the symptoms. The line are original I believe so I'm thinking maybe the starboard line is failing.
Thanks for the input. I should be getting to her this week.

Thx
C

[yorklyn]

I replaced all of my original "hard" fuel lines with rubber ones that were rated for ethanol. After 27 yes I figured it was a good idea.
Your carb should have a small screen/filter where the fuel line attaches (I believe). It may have some crud on it.

[Lumpy]

I'll check that out as well, thanks.

C

[BobCT]

I know i've posted this before but the anti siphon valve doesn't look like anything but a fitting until you remove it, it's going to be the tank/fuel line connection. One down and dirty test is running with the gas cap removed. If the problem goes away it's the ASV

Bob

[Bimmerbill]

Here is a pic of my fuel tank original fittings. Can't remember which was the anti siphon, but think it was the last fitting prior to the flare fitting. I replaced both of mine since I also replaced all fuel lines with A1 hose and added Racor fuel filters.

Your fuel filters are OK? How about the little filter in the carb inlet?