NS8B Exhaust Junk?

[bruce40]

1996 8hp Nissan short shaft. When i got his motor there was fishing line wrapped up in the prop shaft so i replaced the prop shaft seal and replaced the water pump. Im not sure i have the prop shaft seal seated all the way. I tried to press it in with blocks of wood and a vice, but it just didnt seem to seat flush in the housing. I have run this motor about 15 hours like this and havent had any problems except all the exhaust crap dripping out of the housing. Also the prop seems to be about 3/8ths of an inch out from where its supposed to be. (see pic)

This little motor runs great, starts on the first pull every time. Last night i drained out the gear oil and it looked new. I cant figure out where all this crap is coming from if it aint gear oil leaking.

Any Ideas? Thanks, Bruce

 

[pvanv]

Re: NS8B Exhaust Junk?

Looks like the bushing isn't seated all the way on the shaft. I'm surprised you can get the cotter in the prop nut.

Make sure the prop shaft seal is all the way in. It should bottom in its bore. If necessary, you could use the prop and bushing as a seal "pusher", but you would need some washers to span the space between the seal and the bushing.

The thrust bushing is supposed to seat at the end of the splines on the prop shaft, not bear on the seal.

That exhaust junk is likely unburned fuel/oil mix. Make sure you are running 50:1 fuel mix.

 

[bruce40]

Re: NS8B Exhaust Junk?

Thanks for the tip on the "pusher"

I have been running 50:1 all summer, but i did rebuild the carb last fall. Wondering if maybe im running a little too rich, causing all that exhaust crap?

Thanks, Bruce

 

[TOHATSU GURU]

Re: NS8B Exhaust Junk?

It's normal for 2-strokes, but your oil residue looks a like it is emulsified gear oil rather than unburned fuel/oil...Do yourself a huge favor and take another look at a possible leak into the gear case.

 

[bruce40]

Re: NS8B Exhaust Junk?

It looks like bad gear oil to me also. But i did drain the gear case and the oil looked brand new(no water or milky brown junk) I removed the prop housing and prop shaft, the o ring and seal looked good so i put it back together and filled the gear case, took apprx. 300 mls of oil. I then measured the oil in the drain pan, was apprx. 300 mls of gear oil.

The crap seeping out of the hub did not smell like gear oil it smelled like exhaust. The motor is used for slow trolling so it doesnt run much over idle speed. Pulled the plugs and the are coated with oil deposits.

 

[bruce40]

Re: NS8B Exhaust Junk?

Pulled the L/U today... Im not sure if its exhaust or gear oil, the stuff has the consistency of a thick foam like whip cream.

Any ideas?

Thanks, Bruce

 

[TOHATSU GURU]

Re: NS8B Exhaust Junk?

It still looks like emulsified gear oil rather than unburned 2-stroke oil....I would clean all that crap out/off and run it for an hour. Then take a peek again and see if it has returned. Your not running in contaminated water are you?