water tube installation

[mr roach]

ok i had a bad prop & have acquired a quality replacement for my early 70's merc 115 6 cyl. I have installed anew impeller & have been trying to get the lower unit back on for 2 days. I can get it within an inch or so and after removing the lower unit & checking up inside to see if any obstructions are causing the problem and it is clear. It seems the water tube is not falling into place and i do not force copper tubing as i do know it needs to slip in, advice from this site suggested to turn the powerhead to align the shaft so i removed the spark plugs and attempted to install the lower unit and could not feel the splines on the input shaft making contact with the powerhead so to me this suggests the water tube is not allowing me to acquire that last inch or so. Am i on the right track & is there a "trick" to getting the tube properly aligned or am i way off base and need to go about it in a different manner. Thanks for any help you can send my way

 

[ski_bum]

Re: water tube installation

I second this question, I have a 71 Merc 7.5, same issue... What's the trick to getting the lower unit back on?

 

[nbnewbie]

Re: water tube installation

what do you mean "the water tube is not "falling" into place the copper water pickup tube in the mid-section is secured on it's top to the base plate beneath the power head and does not move up or down (not supposed to anyway) the water pump top houseing has a "guide tube" if you bought a top water pump kit it usually has a new one in it that guide tube slides over the copper pickup tube to guide it into the top pump housing there is some vertical tolerance between the copper pickup tube and the top of the pump but not much it is supposed to be a close fit if you are down to the last inch of closeing the gap you're right not to try to force anything because when everything is lined properly you'll be amazed at how easily it actually slips back into place if the guide tube (which is usually plastic) is sliding onto the copper tube then it is not likely that that is what is holding you back check closely that the shift rod splines are aligned with the shift linkage that runs down through the front of the mid section if both the pickup tube and the shift linkage are aligned the drive shaft into the bottom of the flywheel is usually the last step at the bottom of the power head is a base plate that the drive shaft has to go through before the splines enter the bottom of the flywheel the hole in the base plate is quite a bit larger than the top of the drive shaft but it can sometimes hang up there and you just have to kind of feel your way through that base plate before you can align the splines once you get to this last step it can be very helpful to have and extra pair of hands to slowly and gently turn the flywheel (in the same direction that it turns when running usually cw) while you apply upward preasure on the lu and finish bringing it into place i hope you find this helpful good luck

 

[mr roach]

Re: water tube installation

thank you nbnewbie when i removed the lower unit the water tube came out with it & thanks to the internet dr. outboard just said " i already installed the water tube while we switched camera positions" he must have forgot we need that info on the video ( at least i do obviously). I have checked the shift linkage during installation & it is a 1/4 inch from going in so i know that's not hanging me up. I will use your info & see if it goes back together will let you know when i get it fixed. Thanks again for the h20 tube info