mercury 7.5 hp outboard water tube

davids_1718

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Joined
May 18, 2010
Messages
29
Hello to all. I have an early 70's 7.5 HP Thunderbolt Short Shaft that I recently change the water pump on due to purchasing a small fishing boat last year that came with the motor but no carb. I have since replaced the carb, fuel fump. I have 2 questions that I believe may solve my problem. The first question is if my lower unit is on a vice and the propeller is to my right what direction are the impeller fins suppose to be (bending to the right or bending to the left?). I want to make sure I am installing it correctly. I did install it right with the key in place just unsure if the impeller has a right or wrong way of being installed. My second question is being that I have a short shaft my existing water tube is locked in place to the upper housing. How far down to the lower unit is it suppose to be before sliding into the sleeve. The reason I am asking is because it is short enough that it does not pass the housing at all and when I mount the lower unit back on it fits into the sleeve but I have no idea if it is locked tight to the water pump grommet as some people say. Also how snug is the copper pipe suppose to be to the sleeve. Should it be tight or loose. Mine seems to be a different diameter then the other copper pipe that is horizontal to the pump. Is that correct or could it be that my water tube is the wrong diameter?
 
M

Maxz695

Guest
Re: mercury 7.5 hp outboard water tube

turn the shaft slowly in a clockwise direction all vains on the waterpump will move to the right direction at this point A little greese on the vains is a good idea when putting in the impeller. also lightly greese the spines but not the nipple on top if there is one there hope this helps
 

davids_1718

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Joined
May 18, 2010
Messages
29
Re: mercury 7.5 hp outboard water tube

max I was able to get the impeller in with no problem I was just curious to see if there is a right or wrong way because I was not getting any water up the shaft into the block. Do you have any input on the water tube to water guide installation. Is it suppose to be a snug fit or should there be some play in there?
 

thebubba

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Joined
Dec 6, 2011
Messages
17
Re: mercury 7.5 hp outboard water tube

I know this is an old post. Did you ever resolve your issue?
 
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