Re: Johson Seahorse 10 hp problem


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Posted by Ed Mc. (63.17.116.225) on September 16, 2005 at 23:24:16:

In Reply to: Johson Seahorse 10 hp problem posted by Jack Thao on September 16, 2005 at 21:11:00:

The shift clutch (AKA "Shift Dog") in the lower unit is worn and likely the corresponding areas in the forward gear that the shift clutch engages are worn too. What you're experiencing is the clutch being expelled forcibly from the gear since its 'ears' are rounded off and won't hold in.

Caused by wear over the years, hard shifting at too high rpm, and/or slop/misadjustment in the shift linkage.

Solution is to replace at minimum the shift clutch and also replace the fwd gear if it's worn excessively. Which it's likely to be, after many bouts of jumping out of gear.

The gearcase needs to be 'split' then the gears are accessible. You'll want to also replace the o-ring (AKA 'spaghetti seal') that seals the gearcase split; also the propshaft seal.

Inspect the shift linkage for slop, starting at the shift lever and working your way down. There is a clevis under the powerhead, which attaches to the shift lever and also the shift shaft. If the locking screw/tab on this clevis works loose, it introduces a lot of slop in the shifting which can lead to worn gears/clutch. You'd have to pull the powerhead to gain access to this portion of the shift lever, for repairs.

Once rebuilt/renewed, it's important to ensure the shift lever is properly adjusted. You want a slight pre-load on the fwd gear when the shift lever is in the fwd direction. You'll see a locking screw/bolt on the shift lever and a corresponding slotted area thru which the lever has an adjustment range.

One 'sneaky' trick that sometimes works, if both fwd and reverse gears are identical, is to swap gears and shift dog around. Typically reverse gear will be less worn than fwd. But you have to be careful because too much wear and even a flopped reverse will jump and then it's shot too. Note that there are typically differences in the bronze bushings pressed into fwd/reverse gears and you'd have to swap bushings to make this 'sneaky' fix work.

Best if you got yourself a good manual such as Seloc or "Old Outboard Repair Manual Part I". Then you'll have the parts breakdown and all the instructions you'll need.

HTH and G'luck.........ed


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