Re: 1975 Johnson 85hp Water Pump
where is the water pump located on my 1976 johnson 115 horse and how the heck does the lower unit come off
The lower unit is held on by four exposed bolts just below the cavitation plate, and a fifth one hidden by the trim tab above the prop. You have to remove the trim tab (which is easier if you also remove the prop, mark the position of the tab before you remove it) which exposes the fifth bolt. The manual for my 1976 85 HP says to drain the gearbox oil first, but I didn't the second time I dropped it and I can see no reason to, so long as the lower unit is kept upright.
And then there's the trick: the shift rod has to be disconnected from the shift link, and it is hidden up underneath the carbs. If the 115 is the same as the 85, you have to remove the link end nut and the big centre pivot bolt and then split the two halves of the shift link, which allows the shift rod to come free. The lower unit should then drop down if you have also removed the five bolts. Two pairs of hands makes this easier than one pair as you MUST keep the lower unit straight, otherwise you'll bend the drive shaft.
Set the lower unit on some soft ground in the vertical position. The water pump sits on top of the lower unit with the drive shaft goes straight through it. Make sure you have the replacement parts to R&R the water pump, and kits usually come with instructions. The minimum kit has an impeller, a key, and the housing O-ring gasket, grommet(s) and a seal. If the water pump has never been upgraded, you might want to get the upgrade kit which includes a new housing and a stainless housing liner. If your's has the two tube pump (the 85 HP does), the upgrade kit and even the basic kit is getting hard to find, but they do show up on eBay. iboats is usually out of stock.
Installation is the reverse of removal, but you have to be very careful to get the water tube(s) inserted into the pump housing. Again, I am not sure if the 115 is the same as the 85, but these years of J/E used two water tubes (versus the typical one) and each one has an insertion guide tube that you slide down the tube, and into the water pump hole as you lift the lower unit into place. This REALLY takes two pair of hands, as you have to guide the tube(s) and keep the drive shaft straight while you lift the lower unit.
HTH and good luck.
