90hp Looper Not Pumping?

[McGR]

After spending untold hours fixing up a neglected Crestliner, I finally prepared the boat for its maiden voyage tomorrow. One of the final tasks was to test the motor (1995 Evinrude 90hp looper) on the drive prior to dropping it in the water.

I bought this motor with a fixer upper boat and had never previously run it. In preparation for the season I rebuilt the carbs, put in fresh gear oil, new plugs and replaced the impeller. I have owned several outboards over the years and have never had any issues with any of the stated tasks.

Anyway... after a little cranking she fired up and came to life. Everything seemed to be going well except I did notice the pisser seemed a bit weak. Nonetheless, I thought maybe it was normal for this motor. After running the motor for a few minutes I shut it down and decided to inspect the powerhead for any possible issues. First thing I did was to place my hands on the block. I didn't get burned, but it certainly seemed too hot.

So, I proceeded to investigate. First, I pulled out the thermostats. There was some moisture present on them but they didn't seem wet. So, I decided to remove the thermostats and loosly replace the caps. I then ran the motor hoping for evidence of water leaking from the caps... No Water. %$#@@!

I then decided to pull the l/u and inspect. After pulling the lower unit everything seemed fairly normal. I pulled the pump housing and everything looked OK. The only suspicious thing I noticed was the nylon tube that connects the pump to the exhaust housing. It was more or less stuck in the pump. I thought maybe it was supposed to put in the exhaust housing side instead so I did this and reinstalled the l/u. I ran the motor again and it still seemed to be pumping weak and wasn't getting water to the thermostats. So, I shut it off...

So, are there any tricks to running these motors on muffs. What could I possibly have done wrong? Could something possibly be clogged. Any ideas at this point will be greatly appreciated. Thanks.

 

[marinemech1]

Re: 90hp Looper Not Pumping?

These motors are designed to run hot (140 degrees f +\- 15)...you probably don't have an infaray heat gun?
Did you remove t stat covers and start up motor too see if water present?
Has any one changed pump housing (there are two different they ones {look almost identical} depends on model number) Basically split or relieved exhaust or non split line.
Make sure you have corect one if in doubt order one for your model number.
Wayne

 

[McGR]

Re: 90hp Looper Not Pumping?

Hi Wayne thanks for your input. I just got in from removing/inspecting/reinslalling the lower unit for the third time. I'm not sure which housing I have. The one in there looked to be in decent shape so I reused it. Again I didn't find any problems when I pulled the l/u.

So I proceeded to run the motor again. This time I let it idle for about ten minutes while monitoring the motor. It seemed like the pisser eventually started "pissing" normally. I also pulled the thermostat caps with the motor running. This time I did see a flow of water on both sides, though it wasn't too impressive - perhaps this is normal?

I eventually reinstalled the thermostats and let it idle for another five or ten minutes. The temperature did still seem hot to me. However, perhaps you are on to something when you say these motors run hot. My frame of reference is mostly older motors. It did seem that the temperature did seem to stabilize, but it was quite hot to the touch. I splashed some water on the motor during the test, it certainly didn't boil off. Perhaps everything is normal and I'm just paranoid and confused.

I've got access to IR and thermocouple thermometers. Unfortunately, not till Monday. I want to go boating tomorrow.

 

[SparkieBoat]

Re: 90hp Looper Not Pumping?

i just had to repull a foot on which I had replaced the impeller...they had sent the wrong plastic wedge with the new impeller..it was about half the size of the old one and was allowing the impeller to slip...also you may want to connect a garden hose to your water tube (with the foot off) 5/8 water hose slips right on it, and flush out your motor.

 

[McGR]

Re: 90hp Looper Not Pumping?

Well... I guess the pump was OK after all. I took it out today and ran it and it did fine. In fact the pisser was pissing really strong - everything is good. Nonetheless, thanks for the advice yesterday.