1999 Nissan 50hp d2- Question

[flatsdude3]

I recently purchased a used 99 50hp Nissan. Couple questions....I pulled the cover to check the thermostat and there wasnt one?? Im thinking the previous owner removed it. Should I install a new one? The motor seems to run fine now. Also i pulled the lower unit to check the impeller and when reinstalling it I had problems lining up the pump with the telltale and ended up ruining the rubber that slides over the telltale, I have order a new one. Is there any trick to getting that lined up? Also when looking at the parts catalog it looks like there should be a rubber piece on the telltale? Does the water pump just slide over the sharp edge of the telltale? Thanks for any help

 

[TOHATSU GURU]

Re: 1999 Nissan 50hp d2- Question

"Should I install a new one?"

Yes, the engine will run hot if you don't.

"I had problems lining up the pump with the telltale and ended up ruining the rubber that slides over the telltale, I have order a new one. Is there any trick to getting that lined up?"

If you mean the water pipe, no.

"Also when looking at the parts catalog it looks like there should be a rubber piece on the telltale?"

If you mean the rubber/plastic grommet that goes into the water pump housing, yes.

"Does the water pump just slide over the sharp edge of the telltale?"

Yes.

 

[pvanv]

Re: 1999 Nissan 50hp d2- Question

Gotta agree 100% with Elvin.

Also...

I would recommend a Factory service manual, available from any dealer -- money well spent, to help you with these jobs.

You do want a thermostat installed for correct cooling. Removing it can cause the motor to warm up slowly, and then run too hot, as a result of uneven and improper water circulation in the power head.

On a motor of this vintage -- and unknown service life, if dropping the LU, I would recommend a complete wp kit, since you have already done all the labor, unless you are on a very tight budget, and the wp looks "perfect" with no wear marks on the plate and cup. We typically don't change just the impeller, as the plate and cup will also be worn, and will accelerate wear on a new impeller.

As for re-mating the LU to the motor... you have discovered why many shops charge $100 an hour for skilled mechanic's labor. It's absolutely critical that the water tube slide into the rubber grommet in the top of the wp housing. That tube supplies all of the cooling water to the entire motor. Requires some patience and skill to get it right. After you have some experience, they go together pretty well.

 

[WO2]

Re: 1999 Nissan 50hp d2- Question

Gotta agree 100% with Elvin.

Also...

I would recommend a Factory service manual, available from any dealer -- money well spent, to help you with these jobs.

You do want a thermostat installed for correct cooling. Removing it can cause the motor to warm up slowly, and then run too hot, as a result of uneven and improper water circulation in the power head.

On a motor of this vintage -- and unknown service life, if dropping the LU, I would recommend a complete wp kit, since you have already done all the labor, unless you are on a very tight budget, and the wp looks "perfect" with no wear marks on the plate and cup. We typically don't change just the impeller, as the plate and cup will also be worn, and will accelerate wear on a new impeller.

As for re-mating the LU to the motor... you have discovered why many shops charge $100 an hour for skilled mechanic's labor. It's absolutely critical that the water tube slide into the rubber grommet in the top of the wp housing. That tube supplies all of the cooling water to the entire motor. Requires some patience and skill to get it right. After you have some experience, they go together pretty well.

 

[WO2]

Just got an NS50D2- 2002 I think … I’ve had a bit of training and experience on engines and mechanics … observation is this engine has an auto oil feed, so no premixing gas. Is that correct.

 

[pvanv]

Yes.