I have a pair of 350 mercruisers 260 h.p. fresh water cooled 1987 vintage in a sea ray weekender with straight inboard shaft drives.<br />Having once replaced the starboard engine water pump and dealing with trying to get the 3/8 bolts back into the tapped holes I found it a tough job to say the least.One of the bolts on the ajustment arm also retains the alternator bracket and both brackets must be aligned with the tapped hole before the bolt can be started, and of course you pretty much have to do this almost blind where it is located.I am now in the process of replacing water pumps on both engines and have been considering using studs in the tapped holes and esna lock nuts with the washers so that the studs can be inserted first then the pump can be hung on the studs to locate it and finally adjusting the belt tension and tightening it to specs(30 ft. lbs.)This system has to be a lot better then trying to hang the pump assy from a rope and aligning the bracket holes with the tapped holes and inserting the 3/8 bolts.<br />Another detail I now use is to cut a hatch replacement from a piece of 1/2 " plywood that is about 12" shorter then the original hatch with this in place you can lay on the plywood over the engine and reach down to remove and replace the pump.I also have modified a nut driver by extending its length using a piece of tubing in order to reach hose clamps that are further then my arms can stretch.After removing the starboard pump I found some of the impeller blades missing, the next stop for the salt water is the tranny cooler exchanger. I removed the hose that goes to the cooler from the heat exchanger and back flushed the tranny exchanger, this forced out the pieces of impeller that were stuck in the exchanger.I would have liked to remove the tranny exchanger but it also is in a impossible location behind the front engine mount.I would love to ask the designers of these engines to do these maintenance operations in front of me so They might think about locating things in a better place.If anyone has suggestions as to help with replacing water pumps I would appreciate hearing from you. <br />Bill
<br /> I dont design them I just have to fix them. I will agree that some designers should be spayed/nuetered and removed from the gene pool. some boats I have worked on were so poorly designed/fitted that engine removal was nessasary for changing the oil filter.<br /> the studs sound ok. just be sure to tighten them securly and use loctite on them. I use the double nut method for stud removal/installation.<br /> good luck and keep posting