Yamaha F4A

[Ian_Rob]

I have just serviced my Yamaha F4A outboard, including replacing the water pump and impellor.

There are various You Tube videos on this, all of which describe the replacing of the lower unit as ‘requiring patience’. It is pig and took me well over an hour. The shift linkage and exhaust are easy enough but locating the splined end of the drive shaft into the engine is very awkward. Are there any tricks to doing this?

 

[VicS]

The usual difficulty , although it's not clear if this is your problem, is that of aligning the splines on the shaft with those in the crankshaft end.
The solution to this is to slightly rotate the shaft by turning the prop, which requires the unit to be in gear or to rotate the engine by tuning the flywheel, if it is accessible.

 

[Ian_Rob]

Thankyou!