Mercury 1984 7.5 outboard is spitting water...

[abk]

On the transom of my MAC 25 there merc 7.5 . The tell tale shows it is cooling properly until reved up and becomes intermittent. I tried the flush but it didn't seem to help. Any help on the impeller and the tube that runs up through the shaft, gaining access to it for inspection and repair, and a source for these parts? Also, is the water intake the small aluminum looking vent on the lower end of the motor?In the spartan manual it shows how to replace the lube in the lower end but the photo is so poor that I cant seem to locate the "vent hole" so I can change the gear lube (any suggestions on what to use?)Are the 2 black caps on the shaft covering some bolts that I need to remove for access to inspect the coolant tube? How do you remove the caps w/o damaging them, probably just prying them off, but when going into uncharted teritory it is good to be armed with some direction and experience...Geez, lots of ?'s...Thanks in advance

 

[Bob Tigar]

outboard cooling problem

In order to service the impeller you have to pull off the lower unit. The rubber plugs on the lower portion of the shaft expose the shift lever rod. This rod has a clamp that must be loosened. Then there are 2 bolts under the fin that hold the lower unit to the shaft. THese are removed and the lower unit drops off to expose the water pump and impeller. Putting it back together requires aligning the shaft spleen and shift lever rod. It requires some patience. As long as you are going to this much trouble, why not pull the head & clean the water jacket. Over years you get a build up of deposits in the jacket & especially the head.Before you go thru all that, try something else...pull the "telltale" hose off the engine case & rod out the area wiith a small drill bit or nail. That may improve the waterflow form the overflow spout.

 

[Landsend]

you have a baad impeller...

time for a replacement