Nissan 3.5A impeller

[Lovetoboat]

My Nissan 3.5a dingy engine is not producing water through the telltale. I blew compressed air through the telltale and bubbles came out beneath the prop. I pulled the impeller and it looks almost new, and very pliable. Put it all back together and still no water through the pee-hole. Any ideas?
Thanks

 

[TOHATSU GURU]

Re: Nissan 3.5A impeller

The pee indicator is just a visual indicator that pump is working. It can clog up and the engine can still have a good working water pump. While the engine is running, stick a thin wire up through the tube and into the block. That should clear it.

 

[Lovetoboat]

Re: Nissan 3.5A impeller

I tried the thin wire and also tried a reverse flush by connecting a garden hose to the tube. Water came out the exhaust port at the bottom. I put the dingy in the water, started the engine and what appears to be exhaust gas is coming from the pee hole but no water. Also, the prop is turning but is not propelling the boat. I'm baffled.
Thanks

 

[pvanv]

Re: Nissan 3.5A impeller

If everything else is right (telltale clear, good impeller, water tube correctly seated on top of the pump, etc.) you may have a significant base gasket leak. The water jacket could get pressurized with exhaust. If so, the motor probably also runs too hot.

As for the prop issue, you probably have snapped the shear pin. The 3.5's originally shipped with brass shear pins, which often got snapped, if even slightly abused. There are now stainless shear pins available for the 3.5.

 

[Lovetoboat]

Re: Nissan 3.5A impeller

Good call on the shear pin, that's what it was, Thanks!!
Since I had the prop off I changed the impeller and then decided to pull the lower unit to check the water tube. The water tube was seated tightly in the grommet and is clear all the way up to the block. Tonight when I get home from work I'm going to rig up a connection to a garden hose and see if I can pressure flush from the tube through the block.
Tom

 

[pvanv]

Re: Nissan 3.5A impeller

If you verify that the pump is pumping, and the telltale is clear, yet no pee indicator, (but only exhaust gasses), you will want a new base gasket.