O-ring left over from Impeller Kit

[SeaKaye12]

I just swapped out the impeller on my 1977 Merc 850 (4 Cyl).

The Quicksilver Impeller kit included an O-ring about the diameter of the driveshaft. I could see no use for it. The genuine Mercury manual that I have shows an O-ring below the water pump base; but since I wasn't replacing the base...I did not remove it.

So, I re-assembled everything and have the O-ring left over.

Am I missing something? Maybe the kit contains parts that are used on some engines...but not mine? Or...should I take everything apart again and have someone here tell me where the O-ring goes?

Thanks for the help, Chuck

 

[jaybirdtx]

Re: O-ring left over from Impeller Kit

Some models had an o-ring on the upper part of the drive shaft. It is most likely a kit that covers several models.

 

[Chris1956]

Re: O-ring left over from Impeller Kit

SeaKaye12, Actually you should have several large O rings and several gaskets left over as well. That small o-ring fits some OBs with a groove near the top of the driveshaft, as well as the Alpha-1 Gen 1 driveshaft. In addition, if you have PTT, that 3/4" ID O ring will fit the cylinder rod seals, that always leak on my motor.

 

[jtexas]

Re: O-ring left over from Impeller Kit

If your motor now runs with cowling off, but dies when you put it on, you'll know you should have put that o-ring on the drive shaft just below the splines. It prevents exhaust gas from feeding back into the cowling and asphixiating the engine. Otherwise??

 

[AMD Rules]

Re: O-ring left over from Impeller Kit

jtexas,
I was under the impression the shaft o-ring was there to keep water out of the splines to prevent corrosion. If the midsection is sealed to the base of the powerhead with a perimeter gasket, how can exhaust gases feed to the cowl?

 

[SeaKaye12]

Re: O-ring left over from Impeller Kit

Well, my driveshaft had no groove to accept an o-ring...and there was ne evidence of one being there in the past.

I was out on the lake today...and the Merc ran fine...cowling on! What you're describing Jtexas...reminds me of exhaust gas recirculation in cars (EGR).... Sure made an engine run lousy...I hope that's not gonna be the case with my outboard...

I guess that if things remain as they are...I'll leave well enough alone. Maybe next time I change the impeller I'll slide the O-ring on there....


Thanks to all...Chuck

 

[jtexas]

Re: O-ring left over from Impeller Kit

AMD's right...of all the seals and gaskets that can allow exhaust into the cowl, that's not one of 'em...sorry 'bout that...

 

[timmathis]

Re: O-ring left over from Impeller Kit

Wow just one part left over. Lucky!