1997 Johnson 70 hp water pump impeller o-ring

[2tall2]

Model # J70TLEUM. Hope someone knows the answer my local marina/dealer has no clue. Replaced the impeller and housing and found no o-ring under the impeller yet the factory 97 parts diagram show one under a 3 vane impeller. Mine has a 6 vane and 98 diagrams show no o-ring under a 6 vane impeller. Possibly a mid season change. I am getting water in the gearcase but it has been resealed am thinking it's going through the driveshaft hole in the plate onto the driveshaft seals. What's the point of a gasket under the bottom plate if water can come through the center hole. Seems odd to put an o-ring under a rotating part. The aftermarket impeller kit (BRP kits backordered for weeks now) didn't come with one and impeller doesn't have a groove for one and if I install the one called for the housing doesn't sit flush on the plate cause of the o-ring. So do I o-ring it or not.

 

[2tall2]

O.K. found my own answer. Upon further scrutiny between what was installed on the 70 hp during routine service by the dealer and what the factory parts catalogue called for seems that they installed parts for a 1998 engine which has no o-ring under the impeller. Seems the 98 parts ( 6 vane ) will work to keep the engine cool but leakage into the gearcase may be a side effect. The 97 factory water pump repair kit is unique having a 3 vane impeller with a groove for an o-ring. As it stands I'm going to try to get ahold of the correct 3 vane impeller and o-ring until the repair kit comes off backorder. Will see what BRP has done to the repair kit then. Then will see if water is still making it into the gearcase. But the aftermarket kit I ordered to just get going again for this engine was 6 vane with no o-ring so buyer beware may result in water intrusion. Time will tell.

 

[racerone]

----Use the 6 vane impeller comes in the 432955 kit !----That kit is the one that I install on 70 HP from 1980 to 2001 models.----All the same.------No issue with water getting into the gear oil.-------No idea why you would say that the 6 vane causes water intrusion ??

 

[2tall2]

O.K. Yes the factory water pump repair kit does supersede to the part number # you quoted. Still waiting for the backordered 432955 kit to see what's going on. As stated previously the 1997 O.E.M. impeller has a 3 vane vane with an o-ring that fits over the driveshaft under the impeller in a groove between it and the base plate. The aftermarket kit I got just to get it going again has no such o-ring or impeller groove. I always distrust aftermarket components for just this reason. So are you telling me that it is normal for the cavity under the base plate to fill with water and rely on the driveshaft seals below to keep water out of the gearcase? Again what's the point of a base plate gasket then. Just trying to sort this out as there seems to be model change from 97 to 98. That said I now have the O.E.M. 3 vane impeller and o-ring and will install to see if once and for all if the water intrusion into the gearcase is here or elsewhere. Even my local marina/dealer is unsure as what what is going on. As I said previously time will tell unless you can explain to me the engineering changes.

 

[racerone]

Sorry -----But there is no difference between a 97 to 98 model.

 

[2tall2]

O.K. Yes the factory water pump repair kit does supersede to the part number # you quoted. Still waiting for the backordered 432955 kit to see what's going on. As stated previously the 1997 O.E.M. impeller has a 3 vane with an o-ring that fits over the driveshaft under the impeller in a groove between it and the base plate. The aftermarket kit I got just to get it going again has no such o-ring or impeller groove. I always distrust aftermarket components for just this reason. So are you telling me that it is normal for the cavity under the base plate to fill with water and rely on the driveshaft seals below to keep water out of the gearcase? Again what's the point of a base plate gasket then. Just trying to sort this out as there seems to be model change from 97 to 98. That said I now have the O.E.M. 3 vane impeller and o-ring and will install to see if once and for all if the water intrusion into the gearcase is here or elsewhere while I wait for the backordered kit. Even my local marina/dealer is unsure as what what is going on. As I said previously time will tell unless you can explain to me the engineering changes.

 

[2tall2]

I beg to differ.

 

[racerone]

Sorry----The gearcases are the same !

 

[2tall2]

Not according to the 97 vs 98 diagrams I just posted. Explain the the engineering changes please.

 

[racerone]

There are no changes other than a 3 vane impeller.----They quickly realized that the 3 vane impeller was a mistake !

 

[2tall2]

O.K. but what's up with the o-ring under the impeller on 3 vane vs 6 vane and answers to the questions I previously posted about water filling the cavity under the base plate. It's fine to tell me this is the new norm but as a mechanic by trade I look for a more detailed explanation and don't accept vague responses.

 

[racerone]

Good luck with your motor.

 

[flyingscott]

My 6 vane housings have that Oring

 

[2tall2]

So to answer my own questions now. My backordered BRP water pump repair kit finally came in. Very interesting the original 3 vane impeller does supersede to a 6 vane. But also comes with revised thermostat springs and housing that must be installed along with the water pump housing and impeller depending on exact model year. The instruction sheet that came with it also explicitly states that no o-rings are now required between the top of the impeller cup and the housing and under the impeller between it and the bottom plate unlike the original. And yes it is normal for water to be under the bottom plate as it is part of the water/coolant pathway.

 

[racerone]

Well, well----How about that.

 

[2tall2]

Well, well----How about that.

@ racerone. Yah thanks for that. Sounds like you knew the answers. At least I had the courtesy to inform the forum community.

 

[racerone]

Well done !