Re: 1972 650 Lower Unit removal
Pretty straight forward job. THere are 6 fasteners to be removed. One nut at front, two nuts at side (one either side), two nuts underneath above the prop and one hidden bolt under the trim tab. The trim tab has to come off to get access to the hidden bolt. The trim tab bolt is either a hex socket type or a 12 point head type. I've seen both. Can't remember the allen key size but a 7/16" 12 point socket fits the other style.
It will most likely take some persuading to pull the unit off, especially if its been some time since it's been pulled. The shift shaft and driveshaft are sliding splined joints so they just slide apart, with any luck.
There are two schools of thought on the "best" way to pull the unit. Some like to have everything in neutral and others like it in forward. Each have there advantages and disadvantages. I always keep everything in neutral myself. Whichever way you choose, don't play around with the lower unit shift shaft once the lower unit is removed. People get curious and just have to give it a spin to "see what it does" and then end up posting back here that their F-N-R no longer works right
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While apart, carefully inspect the stainless cup inside the upper pump housing and the stainless wear plate under the impeller. If there is even the slightest marring/grooving, they should be replaced as well. Don't forget all new gaskets.
