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7.5 Mercury Outboard issues

W

wmila

New member
Hi I'm new to the board, but have been reading a lot of the posts here and I am looking for some help. My serial # on my 7.5 mercury 2 stroke is 2633432. The problem I'm having is when I prime my engine with a gas mixture of 50:1 the motor starts without any issues. Runs for a minute then dies. I recently replaced the impeller to get water circulating coming from the tell tale hole. In idle the water is not a consistent stream, not sure if it's supposed to be. When I give more throttle the water comes out stronger. But the water is coming out hot as well. I'm not sure if it's a cooling issue, carb issue, fuel issue or all of the above LOL. Any help would greatly be appreciated. Thanks!
 
If you can keep your hand on the left side exhaust plate, then it's not overheating. Run it, in gear, in a barrel and see.

I've seen the tell tale on these plug with ?? crud and become erratic.

Was the old impeller intact when you changed it? No missing vanes that might be blocking flow somewhere?

Jeff
 
Sorry guys for getting back to you guys so long and first off thank you for the quick replies. First the cooling issue is fixed water pump works great impeller and new key plate on the shaft work great. Now for the dying issue it's still happens but I can keep the motor running by pumping the hand pump on the gas tank fuel line. So I'm guessing fuel pump or something not sure???? Thanks!
 
I installed a new diaphram with the gaskets inside the water pump put it back together and started it up notice a difference in how it ran, but it died again after a couple of mins like before. The tube coming out of the fuel pump to the block seems to come off very easily. Im going to try and replace it or try some zip ties and see what happens. I did have that connector on my fuel line but I took it off and used the hose clamp straight to the nipple where it was supposed to be connected. I did not see any fuel leaks. I will get back to you all soon! Thanks!!!
 
Hey guys thanks you all so much for your help. I found the issue. I started think there were spark issues and found out I had spark. I traced it back to fuel issues. Started with the pump since that was the easiest and most accessible. Tire it apart and started cleaning it and blowing out all the cavaities upon doing this a small piece of rubber came flying out. Looked closer and another little piece was lodged in between the fuel filter pieces. Cleared it finished cleaning and reassembled the fuel pump started it up and it runs like a champ no heating issues, water is flowing steady from the tell tale hole and does not die. So I'm ready to go out do some trolling with my boat. Thanks again for all the advice and pointing me in the right direction.
 
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