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overheat ?

R

Rok

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I have a 1987 Evinrude v4 88hp engine. When I first start it at the lake, it overheats quickly at idle and the alarm goes on. After I let it cool, I start and run it fast and it works fine the rest of the day. I have already replaced the T-stats. That did not help. I had the heads off and cleaned the water passages and replaced the water diverters. That did not help. My water pump is a few years old, do you think that could be the problem? or maybe a piece of something clogs up and then gets flushed out at high speed. What do you think? Thanks.
 
Sounds like your water pump is bad. "A few years old" means exactly what? Typically replacing the impeller every 3 years is recommended. If you happened to have sucked in sand and grit it could have drastically reduced the life of your impeller. If you've done dry starts that will really reduce the life of the impeller. And if you used a cheap knock-off brand on your last replacement that can also explain your problems.

I would suggest you pull the lower unit and inspect the stainless steel cup in your water pump. If its in good shape, then install OEM Impeller Kit 5001593 and try again. Be sure to spin the driveshaft clockwise (looking down) as you place the cup over the impeller to ensure the fins are clocked in the right direction.
 
I think you may be 100% correct. I think it will be a winter project. Pulling that lower is a pain due to the shift linkage. Thanks for your help Kevin!
 
Rok said:
I think you may be 100% correct. I think it will be a winter project. Pulling that lower is a pain due to the shift linkage. Thanks for your help Kevin!
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Backing out the shift rod retainer is a bit of a pain, but not impossible. You should be able to drop the lower, replace the impeller, and reinstall in less than 4 hours.

This video is a good run down of the LU removal process --> V4 LU Removal from Brandon's Garage
 
I would say lower unit removal is elegantly easy on a fresh water motor.-----Should be a 1 hr job to replace impeller.
 
Rok said:
Do you guys replace just the impeller, or do you replace the whole waterpump kit? Thanks
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The entire pump kit is $101 for Part #5001594. The impeller only kit is $41 for Part #5001593. If you used a cheap knock off kit, or you've dry run the engine, I would strongly encourage buying the entire OEM kit so you have 100% good known parts. If the last time you used OEM and your stainless steel cup is in good condition, then you can probably get away with just the impeller. If you question any part of your current pump I would just get the whole kit and be safe.
 
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