1970 Sea Raider Fuel System

[MMills]

Hello All,

We recently purchased a 1970 Sea Raider (Tri Cabin) a few months ago, and I was wondering if someone could shed some light on the operation of the fuel system, specifically the tank switches.

The boat has two 80 gallon fuel tanks. I was able to locate a valve in the fuel line near the port and starboard tanks. My question is this.... if I close either of these valves, I am assuming both engines will pull fuel from the other tank?? If both valves are open, will fuel be pulled from both tanks at an even rate?? Are there any other fuel tank valves I may be missing?

It seems reasonable that it would pull from the tank you have the valve open on, however, I have noticed with both valves open, it doesn't seem to use fuel evenly from both tanks.

Thanks in advance! I appreciate the info!

[The Dog House]

I'm not familiar with the Sea Raider fuel system but it is not uncommon for a boat to preferentially draw fuel from one tank over another. In my 1971 F26, if I have both tanks open the engine only draws from the port tank. The length of fuel line from the port tank to the fuel filter is much shorter than the length of fuel line from the starboard tank to the fuel filter. The longer length results in greater resistance, so the engine pulls from the tank with least resistance (the port tank). I need to make sure I only have one tank open at a time to properly manage my fuel.

[MMills]

Thank you sir, I appreciate it info!

[captainmaniac]

This is from a 1969 Sea Skiff manual (the boat was a 28 footer, but the manual is somewhat generic). Only being one year off, it may reflect your config too.

1969%20Fuel%20System_zpst3drz1q6.jpg (73.96 KiB) Viewed 1184 times

So... one shutoff where the fuel line comes out of each tank, OPTIONAL shutoff in the crossover line, and one shutoff at the transition to flex line for each engine. Shutoff for crossover appears to control whether both engines feed off of both tanks, or each has its own dedicated tank. Generator (if you have one) may be tapped in to one of the tanks with dedicated shutoff at the tank and dedicated feed line.

[MMills]

Thanks!! I appreciate it!!