4,5,6 hp Tohatsu/Nissan impeller pin

It has not been detailed here but if the diagrams are to be believed the impeller pin relies on a flat on the driveshaft to 'wedge' the impeller cosequently causing the impeller to turn. Is this really 'the way it is?'. I'm working on a 2000 5hp Tohatsu and a 2004 4hp Nissan. By the way, I'm told that the 'D' on the back of the NSF4A2D designation means an integral fuel tank and connector for external tank. Haven't seen that listed here previously. Also, how can I distinquish between short and long shaft. Decal on outboard doesn't seem to offer this information. Thanks.

Re: 4,5,6 hp Tohatsu/Nissan impeller pin

The water pump info is fully detailed in the Factory service manual, available from any dealer.

Yes, on the MFS4, it is a vertical stainless pin that rests in a flat cavity of the driveshaft, and wedges against the pin cutout in the hub of the impeller. Just like most brands in this size range.

Yes, all MFS4 motors are equipped with integral fuel tank. All newer ones also have remote tank capability, but until a couple of years ago, it was an option to have the 2-tank setup. Many, many motors have been altered to either add or remove the 2-tank setup.

Shaft length is determined by measuring from the top of the transom to the ventilation plate. Short is about 15-17 inches... long is about 20-22 inches, and UL is 25-27", depending on precise model of motor. Again, some motors have had the shaft length changed to suit the consumer's needs.

If you want to know how the motor was originally configured from the factory, you can ask Tohatsu about that specific model and serial at http://www.tohatsu.com/contact.html