Bennett131 Posted June 8, 2015 Report Share Posted June 8, 2015 Oem impeller works fine. Quote Link to comment Share on other sites More sharing options...
sprinklerman Posted June 8, 2015 Report Share Posted June 8, 2015 Yeah cuz they started making them in the 80's thats why.... Thats like saying keep your stock plastic covers on a drag bike IMO but personal peace of mine if you ask meCoupe is right. Quote Link to comment Share on other sites More sharing options...
98_sheester Posted June 8, 2015 Report Share Posted June 8, 2015 Like i said its personal preference... Quote Link to comment Share on other sites More sharing options...
Coupelx Posted June 8, 2015 Report Share Posted June 8, 2015 I know lots of guys that run the stock plastic covers on their drag bike! Quote Link to comment Share on other sites More sharing options...
sprinklerman Posted June 8, 2015 Report Share Posted June 8, 2015 Like i said its personal preference...Nah. It's science. Show me ANY aftermarket impeller that can last as long as an OEM. And overheating is usually due to improper head design or jetting. Or air leak Quote Link to comment Share on other sites More sharing options...
98_sheester Posted June 8, 2015 Report Share Posted June 8, 2015 Nah. It's science. Show me ANY aftermarket impeller that can last as long as an OEM. And overheating is usually due to improper head design or jetting. Or air leak I wasnt good at science But they didnt start making them for shits and giggles is all.. Quote Link to comment Share on other sites More sharing options...
Coupelx Posted June 8, 2015 Report Share Posted June 8, 2015 the impeller floats in its bearing allowing it to rub in the housing. this is why yamaha used a plastic impeller. as far as an improvement in cooling? Look elseware as sprinklerman mentioned. Quote Link to comment Share on other sites More sharing options...
Coupelx Posted June 8, 2015 Report Share Posted June 8, 2015 I wasnt good at science But they didnt start making them for shits and giggles is all.. You arent good at alot of things. It was a solution looking for a problem, like alot of parts on the market. ALOT of cars use plastic waterpump impellers now. BMW comes to mind as one. Quote Link to comment Share on other sites More sharing options...
sprinklerman Posted June 8, 2015 Report Share Posted June 8, 2015 I wasnt good at science But they didnt start making them for shits and giggles is all.. This is true. They made them to make money.Also the tolerances on OEM seem to be more consistent. That being said, if someone needs one to sleep better at night, so be it. Just know there are tons of high hp bikes running stockers without issue. And there are tons of semi stock bikes running 15yr+ OEMs still doing their job. I'd like to see a PD last that long. Quote Link to comment Share on other sites More sharing options...
98_sheester Posted June 8, 2015 Report Share Posted June 8, 2015 Id say a billet would last as long Think plastics wear tolerance to metal if i were to the plastic impeller and gear and a billet one and run it on the ground the same amount i guarantee the plastic will have more material gone. Im not sayin thats what ppl do but the simple fact plastic shards are better than metal if it were to fail... But at the same time you have never had one fail so there should be no worries either way....correct Quote Link to comment Share on other sites More sharing options...
sheerider11 Posted June 8, 2015 Report Share Posted June 8, 2015 I wasnt good at science But they didnt start making them for shits and giggles is all.. So do you run a boost bottle? I had a PD. I'll see if I can find it. It's scored up from getting sloppy and the shaft wearing. Put oem. No issue. Mull finally made a billet with the correct shaft that doesn't wear Quote Link to comment Share on other sites More sharing options...
98_sheester Posted June 8, 2015 Report Share Posted June 8, 2015 So do you run a boost bottle? I had a PD. I'll see if I can find it. It's scored up from getting sloppy and the shaft wearing. Put oem. No issue. Mull finally made a billet with the correct shaft that doesn't wear I run a cross over tube thanks tho man..i bet it should be plastic too instead of aluminum tho huhAnd the next argument is...."i actually made of pvc" yes it works but the tolerance of plastic to metal is self explained 1 Quote Link to comment Share on other sites More sharing options...
Bennett131 Posted June 8, 2015 Report Share Posted June 8, 2015 Id say a billet would last as long Think plastics wear tolerance to metal if i were to the plastic impeller and gear and a billet one and run it on the ground the same amount i guarantee the plastic will have more material gone. Im not sayin thats what ppl do but the simple fact plastic shards are better than metal if it were to fail... But at the same time you have never had one fail so there should be no worries either way....correct It's not the impeller itself that wears, it's the shaft. Quote Link to comment Share on other sites More sharing options...
sprinklerman Posted June 8, 2015 Report Share Posted June 8, 2015 So much newb in this thread. Quote Link to comment Share on other sites More sharing options...
blowit Posted June 8, 2015 Report Share Posted June 8, 2015 Plastics are indeed used in engines. I am not sold on the idea though. The physics of plastic breakdown with age, heat, and oil intrusion is well documented. There is a finite life of plastics in that environment! Vibration and cavitation in this application also apply. HOWEVER, it is never wise to assume an OEM does not know what they are doing. The impeller certainly can make contact with the housing if tolerances are not working out. OEMs have much looser tolerances and Yamaha does not have the time to personally "fit" each pump so it does not make contact. Personally, I feel the whole design is a little out dated as the mechanical seal and aluminum impeller is a much more robust design such as Suzuki and Honda like to use. A few ways in which our pump improves things is due to the material, we can open up the vanes to pump more water per rev. We also designed it "tighter" than OEM as any gaps actually cause a loss of efficiency. We also intentionally leave a small nub at the center of the back so if contact is made on the back, it is a very small point, not the whole back side! We always recommend completely fitting the pump on the clutch cover and testing for contact but those issues are very scarce. Our shaft should meet and exceed OEM spec for strength and wear resistance. We thoroughly tested all of them. It is approx 3X harder on the surface than the comparable stainless designs. They do this because they can just order ground rods and cut and go. We actually have to make them, surface treat them, then grind them, then apply our friction coatings. But it makes for a better product. One question I might have for the OP in this case is if the bike was being ridden when over heated? Remember that you must have air movement across any water/air exchanger to get heat transfer to the air. Some will be radiant but air flow is a must. Brandon Mull Engineering Quote Link to comment Share on other sites More sharing options...
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