Nissan 5 HP motor should be OK...
...with the external tank. I've seen this modification made a few times to that particular motor (NS5B, I think is the model?). Personally, I prefer the external tank anyway- Less likely to run out of fuel when I need it most. I don't remember anyone mentioning a need to beef up the fuel pump. Of course, on the H23, the fuel 'locker' is higher than the outboard motor mount anyway- This creates a siphon, which takes away most of the need for a stronger fuel pump. I'd recommend turning off the master fuel valve when the motor is not in use, to prevent flooding its carburetor. The post about either removing the internal tank, or installing a valve between the internal tank and the tee connector is spot-on. I've seen both, but I think the preferred method is to remove the internal tank. There are some advantages to the 2-tank setup, as well- If you ever have to drain the internal tank (a good idea for transporting), all you have to do is put the external tank lower than the internal tank and open the valves and vents- Gravity takes over. The same is true in reverse, so you MUST remember to close that valve when you use the external tank as the motor's fuel source! Finally, I'd recommend going with the Nissan-style fuel line connectors, for two reasons. If you look at the front of the motor, there's a rubber plug next to the 'kill' button- The fuel fitting should fit there nicely, as that's where Nissan puts them when they build the motor for use with an external tank. The other reason I recommend them is because the 'OMC' type connectors SUCK- Always leaking, and sometimes falling off(!!) when you need them most. Good luck! If you're not too mechanically inclined, a good small-engine mechanic or outboard repair person ought to be able to make this modification pretty cheap- perhaps even as cheap as a 12-pack of their favorite beverage and parts at cost. As always, if you have any questions, just holler... --Jon Bastien H25 'Adagio'
