o-ring under impeller johnson 90hp

[outboardkiwi]

I have just purchased a new water pump kit for my 1989 90HP Johnson J90TLCEM. The new pump kit replaces p/n 434421. My question is on my old impeller there was an o-ring under the impeller in a deep groove, however in the new kit there is no o-ring supplied nor does the groove under the new impeller look deep enough to accommodate an o-ring, have they moved away from installing o-rings under the impeller on later model water pump kits for do I have the wrong kit, apart from the above the new kit looks identical in every respect. Thanks

 

[WillyBWright]

Re: o-ring under impeller johnson 90hp

Welcome to iboats.<br /><br />I think they put that o-ring in there so you could just replace that if it wore out. But if you're going to the trouble of taking the gearcase apart to service the water pump, why replace just the o-ring? I think the new updated impeller just eliminated one extra part that could fail.

 

[rodbolt]

Re: o-ring under impeller johnson 90hp

hello<br /> well there again the engineers failed to consult with me before making changes. I do know that some of the aftermarket kits did not use the oring under the impeller. now would be a good time to refer back to the selling dealer to see if he has any info.<br /> good luck and keep posting

 

[seahorse5]

Re: o-ring under impeller johnson 90hp

That is a several year old kit that you bought. the current kit number for your 90 is 5001594 and it includes the oring.

 

[outboardkiwi]

Re: o-ring under impeller johnson 90hp

Thanks for the replies, the new pump in question is an after market pump which states it replaces 434421. Is there any difference in performance or life using an impeller that doesn’t have an o-ring under it?

 

[seahorse5]

Re: o-ring under impeller johnson 90hp

If possible, use the factory kit for best results.

 

[rodbolt]

Re: o-ring under impeller johnson 90hp

like I said<br /> the sierra kits dont usually have the oring. like seahorse says cough up the extra and buy it from a dealer. many aftermarket kits dont use that oring.<br /> good luck and keep posting

 

[DHPMARINE]

Re: o-ring under impeller johnson 90hp

Could that oring be extra protection from the impeller pushing water down towards the driveshaft seals?Just guessing,but can't think of another reason.<br />DHP

 

[DHPMARINE]

Re: o-ring under impeller johnson 90hp

Could that oring be extra protection from the impeller pushing water down towards the driveshaft seals?Just guessing,but can't think of another reason.<br />DHP

 

[chicken louie]

Re: o-ring under impeller johnson 90hp

mi just replaced my impellar and the o ring on the shaft goes on the top of the shaft just below the splines to keep the grease on the splines, allso dont put any grease on the top of the shaft or you get a hydraulic lock on your bearing.dont know if your o ring is the same.

 

[seahorse5]

Re: o-ring under impeller johnson 90hp

Louie,<br /><br />On the factory water pump impellers for V4 and V6 motors, there is a larger diameter and "fatter" oring that installs inside a recess in the impeller hub. This is a different oring that is used on the driveshaft of earlier outboards.

 

[WillyBWright]

Re: o-ring under impeller johnson 90hp

But specifically why is it there? What does it accomplish that molding a slight ridge in the impeller doesn't? As far as the aftermarket impellers, there's probably a patent issue and they can't use them.<br /><br />Another question posed in a different category...why rubber? How about urethane or some other space-age material for impellers? Or are they Neoprene which I suppose IS a space-age material? How about Viton like they use on float valve tips?

 

[outboardkiwi]

Re: o-ring under impeller johnson 90hp

Hi again team and thanks for the replies. I have now purchased a genuine Johnson/Evinrude impeller, which includes the o-ring under it, to replace the impeller that came with my aftermarket water pump kit, and will use the impeller that came with the aftermarket kit as an onboard spare if needed. I feel OMC must of put that o-ring there for a reason and as DHPMARINE said, could that oring be extra protection from the impeller pushing water down towards the driveshaft seals?

 

[seahorse5]

Re: o-ring under impeller johnson 90hp

The water pump kits were redone a few years ago. The hardness (durometer) of the rubber on the impeller was changed also with the addition of the oring. The new pumps move more water than the earlier ones did.