Water Pump Evinrude 7.5

[Burnsoftx]

This is a 1982 Evinrude 7.5 A previous message on this board from last year prompted me to replace the piston rings. Just finished rebuild with new Pistons, Rings, and Seals. I have the engine up on a stand with the lower half in a Trash can of water. The engine starts on first or second pull, runs smooth. However, I have not run the engine for more than one or two minutes because no water seems to be running through the engine. I see some white smoke exiting the water discharge hose, but no water. If I pour water into the discharge hose while the engine in off, I see a steady stream flowing from the water intake at the base near the prop.<br />Is the Water Pump activated by the exhaust pressure against a metal plate at the discharge hose?? Gaskets are good and I do not see any problems with compression leakage.<br />The only thing I am unsure of is the alignment of the brass/copper pipe attached to the bottom of crankcase which protrudes down the lower unit next to the drive shaft. When I have the engine off the base unit I can see the guide hole at which this tube should be inserted. I have removed and replaced the engine twice, am I missing the mark with this tube? or something else? Thanks for your help...

 

[CAPTBLACKSMARINE]

Re: Water Pump Evinrude 7.5

WELL YOU SHOULD PULL THE FOOT IT IS ALMOST IMPOSSIBLE TO ALIGN THE WATER TUBE FROM UP TOP AND KNOW THAT IT IS RIGHT. ALSO IF YOU REBUILT THE MOTOR YOU WOULD BE ALOT BETTER OFF TO GO AHEAD AND REPLACE THE WATER PUMP IMPELLER REAL CHEAP INSURANCE ON NOT COOKING A REBUILT POWERHEAD.

 

[Burnsoftx]

Re: Water Pump Evinrude 7.5

Thanks, I will take the foot off tomorrow. I will need to order the impeller. Does Ii-boats.com ship quickly?? or should I use a local shop to order? Is there a trick I need to keep in mind when I am ready to replace the foot? Any springs or O-rings to watch out for?

 

[CAPTBLACKSMARINE]

Re: Water Pump Evinrude 7.5

NO THE IMPELLER REPLACEMENT IS RELATIVELY SIMPLE ON THIS ENGINE.YOU SHOULD HAVE NO PROBLEM,NO SUPRISE PIECES TO FALL OFF SO IF SOMETHING DOES IT IS BROKE.BE SURE BEFORE YOU PUT THE FOOT BACK ON TO BE SURE THE RUBBER GROMMET IS STILL IN PLACE IN THE WATER PUMP HOUSING WHERE THE TUBE GOES IN IT .YES BUY THE IMPELLER FROM A LOCAL DEALER THE LITTLE YOU SAVED OFF LINE WOULD NEVER BE WORTH IT,THEY ARE FAIRLY CHEAP .DO NOT REMEMBER EXACT PRICE ON THAT ONE BUT SHOULD BE LESS THAN $25 AND I THINK MORE LIKE $15. GOOD LUCK

 

[Burnsoftx]

Re: Water Pump Evinrude 7.5

Well, I pulled the foot down afew inches and was able to direct the copper tube into the correct position. Refilled with gear oil and started her up. I am getting a strong steady flow out of the Water Discharge hose. When I place my hand in water coming out of the discharge hose, it does not feel warm at all. I have only let the engine run at idel speed for about ONE minute but the Head is too Hot to leave my hand on it. The main crankcase is still cool, but the Head and the shaft midway down toward the prop are very Hot. What am I missing. I have not replaced the impeller yet, am i wrong to assume that it is working properly because of the strong water flow from the discharge hose? It does seem to me that water is not flowing thru the heads for some reason....

 

[robsd]

Re: Water Pump Evinrude 7.5

It should be working correctly. My 9.8 takes a few minutes to get some warm water out. You might try running it a little more and at more than an idle...just use caution. The discharge tube comes directly from the engine block.<br /><br />The impeller change is simple but there is one part to be aware of. There us a loose piece of metal that goes on the shaft. The parts manual calls it a "key". It's small and easy to lose if your not careful. The keys purpose is to keep the impeller from spinning on the shaft. It's not hard to replace...just something to be aware of. Local shops have non-OEM impellers that fit most engines. Mine cost $11.<br /><br /><br />Good Luck,<br />Rob

 

[Burnsoftx]

Re: Water Pump Evinrude 7.5

As a related question: The discharge hose I am using is made of extra fuel line. (without a cap with a small hole at the end) Does the Caliber or internal size of the tube have anything to do with this? Should I reduce the size of the hose with a constriction of some sort? Would this allow the water to stay within the head longer and increase cooling?

 

[Burnsoftx]

Re: Water Pump Evinrude 7.5

Should I reduce the size of the Discharge hose with a constriction of some sort? Would this allow the water to stay within the head longer and increase cooling?

 

[Burnsoftx]

Re: Water Pump Evinrude 7.5

I have removed the Thermostat. It looked like it was not opening. Is this OK to run like this?

 

[Burnsoftx]

Re: Water Pump Evinrude 7.5

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[Burnsoftx]

Re: Water Pump Evinrude 7.5

Just Ordered the Manual from the iBoats link.<br />SELOC Volume II (2-60HP 1971-89) Part # 230-008X.<br />"When all else fails -- Read the Manual" <br />Now I can tell my wife I am being Proactive....

 

[btwitche]

Re: Water Pump Evinrude 7.5

To burn. Be carefull when changing the ammount of restriction on the discharge hose as you might disrupt the flow balance within thre cooling system, sometimes even allowing exaust gasses to force thier way into the cooling system. Many times these are calibrated so that the cooling system is able to maintain a certain ammount of pressure within the cooling jackets in the engine. It could lead to air/steam pockets and subsequent overheating. Also, dont remove the thermostat. It can lead to a host of problems including uneven cooling, plug fouling and even overheating.