NS5B won't start...

[eMKay]

I bought a boat, it came with an NS5B, first thing I did was start it up, it ran great but no water was coming out of the water output, so I ordered a water pump kit, installed it, and started it again but this time it ran like crap so I shut it off right away. I looked in the fuel tank that came with it, RED GAS! It was full of rust, so I got a new tank, new gas, and cleaned out the carb but now when I try and start it I get nothing, and fuel is pouring out the bottom end, and the primer bulb will not firm up, it firmed up within 3 pumps before, but now will not at all.

One thing I noticed was where the fuel enters the carb, a little box attached to the carb, there is a diaphram that appears to be leaky, is this what holds pressure? Is fuel just pouring past this and through the carb? I'm an auto tech so I'm mechanically inclined, but I know squat about 2 stroke engines.

 

[TOHATSU GURU]

Re: NS5B won't start...

That is a fuel pump and it might be the problem.

 

[trimjb]

Re: NS5B won't start...

Seems to me that if your getting raw fuel out the lower end then the float/needle must be stuck.
I'm getting ready to install a rebuild kit on mine as we speak. The block you inquire about has a couple of small reed valves in it to let the fuel into the carb. I would think the gaskets/diaphragm need to be leak free for it to operate properly.
John

 

[eMKay]

Re: NS5B won't start...

The float and needle are ok, I took it apart and cleaned it. the diaphragm definitely leaks, so that is the fuel pump then? I put some gasket maker on both sides of the diaphragm, let it cure, and put it back together. It runs now, but the brand new impeller I put in for the water pump was shredded, so I put the old one back in taking care to shove it in there the right way (the way the engine turns right?) and it seems to work. I'm ready to ditch this 20 year old polluter and get a 4-stroke.

 

[TOHATSU GURU]

Re: NS5B won't start...

Never replace just the impeller. Always replace with a kit. Chances are the wearplate and liner need to be replaced...We don't even sell impellers(alone) to the public just to keep them from tearing them back up.