'75 Merc 7.5 long shaft

[gyrenebill]

Bought this for good price. Used the first time and found that it starts in Forward (lever showed Neutral). Have used it for 3 months that way, and decided to make it right. Put shift lever in N (forward) dropped lower unit, moved lever to Forward gear, and tried to put lower unit back on. Didn't move anything, except shift lever after unit free. LU goes back in and stops 1" short of mating. Water line in place, and prop free wheels one way, but not the other (still in forward). Any ideas? Did everything like I have read here, but 3 hours of trying and no luck.............. Any ideas? Steelhead season is upon us and I am itching to go. Thanks for any help!

 

[7920hpMercury]

Re: '75 Merc 7.5 long shaft

Sounds like it was indexed wrong as you say if the shift lever was in neutral and the lower unit was in forward.

There is a little plastic coupling (you can see it if you look up in the mid section where the shift lever goes) that might be buggered as they say in the UK. I would suggest that you shift the lower unit in forward, flat on top of shift shaft on the lower unit facing aft. And shift the gear shift lever in forward and try to reassemble. You might have to jiggle the shift lever to get it to engage, make sure the water tube is aligned, and rotate the flywheel a little to engage the drive shaft splines. You can tell if the drive shaft splines are engaged by rocking the flywheel and watching to see if the prop is rocking too (all in forward still).

Good luck and failing that, I would try to clean out the plastic coupling spline grooves.

Great motors!

 

[gyrenebill]

Re: '75 Merc 7.5 long shaft

That is precisely what I have been doing. One time it lined up and I had 1/2" gap, but the water line wasn't lined up with the impeller housing. By the time I got it to, the LU had moved enough to come disengaged. There was a 4" piece of rubber hose on the water tubethat was "floating" free up and down the water line. Appears that it was a guide, but was hard and brittle and couldn't get it to go in the top of the impeller unit (swollen up too much). I will go and buy another piece of hose to match the opening in the impeller unit, it has a 1/2" shoulder the hose slipped into, and keep on trying with the water line in the sleeve. Thought that there was something "magical" that I had missed. As usual my law "Wilson's Law" , verifys that Murphy of Murphy's Law was optimistic when it comes to me and "Minor" repairs! GRRRRRRRR! Thanks for the info and will try not to bugger it up