3 blade impeller or 6 blade? Which is better?

[boatster]

So my 1996 Johnyrude 70 2 stroke has a three blade impeller. I just purchased an impeller kit and the new impeller is a 6 blade. Can someone tell me which is a better design? Which is the newer type. I'm not even sure my 3 blade is going bad but I wanted to replace it anyways. But at $75 for the kit I'm now questioning myself. <br /><br />So can someone answer whats the diff between the 3 or 6 blade impeller?

 

[rickdb1boat]

Re: 3 blade impeller or 6 blade? Which is better?

This is an updated impeller, that should be installed along with other updates that were part of a service bulletin issued by OMC. Included is a different t-stat and possible relocation of the telltale hose on the block. Check with your dealer before you install this impeller, to find out other changes that must be made to accomodate the increased output of the pump...

 

[Dhadley]

Re: 3 blade impeller or 6 blade? Which is better?

So can someone answer whats the diff between the 3 or 6 blade impeller?

Yep. 3 blades.<br /><br />Sorry!! Sometimes I just cant help it.<br /><br />They were six blades for a long time and then someone thought 3 would work. Now, which do you think will move more water? This was in an era when OMC was cutting costs wherever they could and in some cases wherever they shouldn't.<br /><br />Yes, there were several other things to look at like Rick mentioned. Good advise.

 

[boatster]

Re: 3 blade impeller or 6 blade? Which is better?

Har har har.... Yeah I wasn't sure if 3 blades constituted a difference. I'm a bit slow <br />I should have stated a diff in performance...<br /><br />About the updates I'll look into it. I did get new t-stat springs and telltale nipples so I'll see if those pieces on my motor need updating. Thanks.

 

[ob]

Re: 3 blade impeller or 6 blade? Which is better?

What the bulliten calls for on the tell/tale is if you replace the three flute impeller with the six flute,to discard the restrictor and use the grommet supplied in waterpump kit and just run the tell/tale hose thru the grommet without a restrictor.The kit will also provide instructions as to what spring and T/stat cap to use depending on which is currently on your engine.