350 Mag cooling issues HELP
#1
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Joined: Jun 2013
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I just got a 2002 Donzi 28 ZX with twin 350 Mags. One of the engines were overheating so I pulled the impeller and it was shot I replaced it and engine was still over heating I know there in nothing stuck in the system after the impeller because I have a T with fresh water flush out and the engine runs great on the hose so it have to be somewhere from the out drive to the impeller but I haven't seen anything about this maybe someone can help
Thank You
Thank You
#5
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Joined: Jan 2007
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From: Sweet Home, North Alabama and Orange Beach
On the hose you have no load on the engine and heat build up is less...this is assuming you have not ran with muffs on the hose. Run with muffs on hose to to verify that is where the problem is. Those hoses can fail and collapse and not leak since they are under suction and not pressure. Thats why it is a different type of hose with a steel spiral to keep it open, the internal lining can sag reducing water flow.
Last edited by looseconnection; 06-20-2013 at 06:19 AM.
#6
What everyone said plus check your actual pump and pump plates for wear if you have the new style with stainless steel wear plate change it I have head pumps that were worn that do not want to do build pressure
#8
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Joined: Jul 2012
Posts: 446
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From: Delaware
It isn't that easy. If you think that is what it is I would pull the plastic piece off inside of the transom. You will see the raw water hose is attached to a 45 degree fitting inside. That fitting is held on by two bolts. Pull that and double check if it is clogged. You will see white corrosion and the hose would be collapsed.
#9
If you just changed the impellor, the housing could still be badly worn causing the low water flow. Also verify the hoses were put back on the correct ports on the pump. I still get burned by this once in a while.


