Problematic Honda BF75A gearshift

Honda BF75A gearshift problem

My 1999 model 4-stroke Honda BF75A developed gearshift problems last.season. Started with gear crunching while out fishing, so I limped home on auxiliary engine. I have renewed the Honda control unit in cabin, the gear cable and all external gear linkages and checked that the gearbox itself is ok. On this model the gear change is transferred from the external linkages outside the powerhead horizontally through the powerhead innards before a final internal linkage transfers the change downward to the gearbox. I can operate gear selection manually so I know all linkages are fine. I can set the gears fine in harbour, take her out on the water, run through some gear changes, and she performs fine for a short while, and then the gear crunching and gear jumping starts inexplicably again This problem starts when the powerhead reaches operating temperature , but why? Has anyone experienced this problem, and what did you do to resolve it?

Thanks

Don

Hi Don,

OK, more questions than answers. Does it suddenly jump out of gear? Or, do you mean it "crunches and grinds" only when you are attempting to change/select a gear?

See if you can explain in detail how you "operate gear selection manually". What I'm asking is; do you unhook the shift linkages under the hood or the shifter cable at the selector box... what part exactly do you place your hands on to accomplish a shift...that sort of thing. It might provide a clue.

When you say "the gearbox itself is ok", does that mean you've disassembled and inspected the clutch and shift slider and spring assembly? Items 1,6 and 4 in the link below? And, if so, what did the gear oil look like during the service?

Sorry to be so inquisitive but it's just got to be part of the process.

http://www.boats.net/parts/search/H...TA VIN# BBAL-4000001/PROPELLER (2)/parts.html