Nissan NSF4A2 service manual?

[KLee001]

I just bought an NSF4A2 motor, and I can't get a service manual for it anywhere. I've ordered it twice now and it's getting frustrating. The first time, they sent me the manual for the MSF4/5/6B,C motor and proceeded to tell me it's the one for the 4A motor and that it had superseded the one I ordered. After an argument with them telling them it says on the first page it's based on the B motor, and there is a whole chapter in the back for things specific to the C motor, but nothing anywhere for the A motor, they agreed to take it back. I ordered the one I wanted from a different place, with specific written instructions that I didn't want them substituting anything for the specific book I ordered, they also sent me the one for the MSF4/5/6B,C. They don't rewrite manuals for different models for no reason, and if it has no mention of the 4A motor anywhere, than I know it will be missing something I will need to know at some point.

Does anyone here know what the differences between the motors are?
Thanks in advance!

 

[pvanv]

The A, B, and C designations are minor revisions to the original MFS/NSF4 motor. The A and A2 were the earlier productions, while the B and C are later. The 4A2 uses a slightly different carburetor than the later models -- the B and C are based only on different emissions standards -- that's the only real difference in the motors.

The A2 carb is best for reliability and idle (and, BTW, the 4/5/6 blocks all are identical)... and the motors merely use different carbs for different hp outputs... so, if you need to increase hp by 50%, you can install the carb for the 6A, and you are good to go.

The basic motor and block are identical across all those sub models. The B and C have a one-piece ignitor, where the A models had separate exciter, pulser, and ignition coils, and the A also had a separate starter "pulley" or cup that attaches to the flywheel cup, whereas later models have that cast integral with the flywheel cup.

Because the 4A is almost 20 years old, and considered obsolete (outboards typically don't last 20 years in salt water), the old service manual is out of print. However, the parts catalogs for the various models are still available, and do show those minor differences. Servicing is the same for all models, so the current Factory service manual is proper for your motor.

 

[TOHATSU GURU]

The correct manual is part number 003N21034-1-NS. We still have them in stock because I was smart enough to buy all of them that Tohatsu had when they went NLA

 

[KLee001]

I appreciate the info!
After arguing with the second place that sent me the manual for the B/C motor, they looked in back and found the 003-21034-1 manual on their shelf.