Yamaha 2B 6A1 Power Head Removal

[nanofkyle]

Recent power loss, in otherwise normal 2HP two stroke outboard motor, makes me want to check for possible carbon blockage at cylinder block/head exhaust and silencer ports. Have removed the six hex headed bolts and opened a 1cm gap between power head and transmission unit. Is it just brute force to separate crank shaft from drive shaft or is there something else I should know, eg a dowel pin? Would welcome advice, or offer for sale of a workshop manual. Best wishes. Ron

 

[steve28]

it should come apart, what may have happened is the drive shaft may have corroded onto the splines. they use a square section tube as the shaft which is steel.
If it rufuses to budge it would pay to open the gearcase and remove the circlip from the transfer gear if only to stop it being damaged.
worst case by forcing is you will need a water pump top housing as the shaft is likley to draw the pump impeller pin up through it.

pm me if you need more help.


steve

 

[nanofkyle]

Thanks, Steve, for that. Now alert to consequence of prising the crankcase and drive shaft castings apart with too much force. Intend to change impeller, too, but will try using the play which I already have to rock things around. Job currently flooded with loads of penetrating oil. Ron