Velislide Posted November 20, 2009 Report Share Posted November 20, 2009 Well, I bought all new OEM parts to totally rebuild the water pump, and I have a question. The water pump shaft slides through the oil seal, the bearing, washer, etc and pop the clip on. When turning the water pump by hand, it spins inside the bearing. Whats going to keep this shaft from falling apart, since its spinning metal on metal, inside the bearing inner sleeve? Shouldnt the bearing turn when you turn the water pump? lol, or does it just start spinning so fast and heat up, where it expands inside the bearing and then the bearing starts doing its job? Could this heat be causing the plastic gear to get soft and strip out from the metal pin? This is what happened to the last owner obviously... how long can I expect the OEM pump to last? Quote Link to comment Share on other sites More sharing options...
Glamis321 Posted November 20, 2009 Report Share Posted November 20, 2009 your bearing is probably bad. i would replace the bearing and it should solve your problem. also mull engineering has a nice water pump head that fits on the stock shaft so you dont have to worry about the plastic one flying apart. they also have a billet gear too i believe Quote Link to comment Share on other sites More sharing options...
Velislide Posted November 20, 2009 Author Report Share Posted November 20, 2009 Its all brand new OEM from Yamaha. Everything water pump related was replaced. Quote Link to comment Share on other sites More sharing options...
bansheesandrider Posted November 21, 2009 Report Share Posted November 21, 2009 Did you damage the bearing when you installed it? Is there dirt in the bearing preventing it from turning? How easily does the shaft turn in the bearing? I highly recomend a billet impeller since the plastic one is notorious for failing, if I was buying a billet impeller, I would go with the Mull Engineering unit that presses on the stock shaft because I have seen several ProDesign impellers that were heavily grooved by the seal. You could probably put a drop of Loctite Bearing Mount on the shaft before you install it, but that will make it VERY difficult to get apart, once it sets up the shaft should be tight in the bearing. Quote Link to comment Share on other sites More sharing options...
blowit Posted November 21, 2009 Report Share Posted November 21, 2009 Its all brand new OEM from Yamaha. Everything water pump related was replaced. I would highly suspect your bearing has issues is the shaft spins freely in the bearing. It may be that you got some debris in the bearing during assembly but should be looked at. If the pump is ran where the shaft is spins in the bearing, it will only last minutes. I hate to toot my own horn but we have identified the issues in the Banshee water pump and built fixes for them. New plastic goods should last a while but if things get hot, it is all over and you will not know it until the motor is a crispy critter. Mull Engineering Quote Link to comment Share on other sites More sharing options...
HiRoller Posted November 21, 2009 Report Share Posted November 21, 2009 Could be melted plastic from the gear inside the bearings, thats what happened to mine. I also HIGHLY recommend a high flow billet impeller. Your bike will run cooler and last longer. Quote Link to comment Share on other sites More sharing options...
lt1bird Posted November 21, 2009 Report Share Posted November 21, 2009 I think its normal for the water pump shaft to spin on the bearing... once the bearing catches up in speed it will spin the same speed but will lag at first. Its all a slip fit other wise you would need to press the water pump impeller into the water pump...Mine are all slip fit... Whats that about the platic melting in the bearing? Ive seen one before do that on a motor, where is that plastic come from? Did look like there was any white plastic inside the bearing like a varier etc..... Quote Link to comment Share on other sites More sharing options...
bansheesandrider Posted November 22, 2009 Report Share Posted November 22, 2009 I think its normal for the water pump shaft to spin on the bearing... once the bearing catches up in speed it will spin the same speed but will lag at first. Its all a slip fit other wise you would need to press the water pump impeller into the water pump...Mine are all slip fit... Whats that about the platic melting in the bearing? Ive seen one before do that on a motor, where is that plastic come from? Did look like there was any white plastic inside the bearing like a varier etc..... It is NOT NORMAL for a shaft to spin in a bearing, this leads to damage to the shaft and bearing, eventually something will fail. Almost all shafts are softer than bearing races so if the shaft is spinning in the bearing the shaft is going to wear and evfentually will start leaking or break off. Even if you can push it together by hand it should be tight enough that the bearing spins, not the shaft spinning in the bearing. It really shouldn't push together by hand, it should have to be lightly tapped together with a soft hammer. Quote Link to comment Share on other sites More sharing options...
Rodneya Posted November 22, 2009 Report Share Posted November 22, 2009 It really shouldn't push together by hand, it should have to be lightly tapped together with a soft hammer. The OEM water pump is plastic. You use any type of hammer on that you are asking for the pump to fail. Read the Yamaha manual. There is no mention of having to use any force as it not a press fit. Mine went in with no effort at all, just like it came out. Quote Link to comment Share on other sites More sharing options...
bansheesandrider Posted November 22, 2009 Report Share Posted November 22, 2009 It really shouldn't push together by hand, it should have to be lightly tapped together with a soft hammer. The OEM water pump is plastic. You use any type of hammer on that you are asking for the pump to fail. Read the Yamaha manual. There is no mention of having to use any force as it not a press fit. Mine went in with no effort at all, just like it came out. A soft hammer is a rubber or plastic hammer. I have tapped all of mine together and have never had an impeller fail, even when I have had to reuse a stocker when making a repair. You could also use a block of wood, the key is to know what you are working on and apply force accordingly. Quote Link to comment Share on other sites More sharing options...
HiRoller Posted November 22, 2009 Report Share Posted November 22, 2009 Whats that about the platic melting in the bearing? Ive seen one before do that on a motor, where is that plastic come from? Did look like there was any white plastic inside the bearing like a varier etc..... Sorry I meant melted plastic from the plastic gear. Quote Link to comment Share on other sites More sharing options...
Velislide Posted November 23, 2009 Author Report Share Posted November 23, 2009 Everything like I said was replaced. OEM Bearing OEM Water pump Shaft & Impeller OEM Gear OEM pump cover OEM Oil seal The shaft going into the seal and bearing was a tight and snug fit, and the bearing turns fine, it turns over a little stiff like any new bearing. I just dont see how if you can slip the shaft in by hand, whats to keep the shaft from spinning inside the bearing. Quote Link to comment Share on other sites More sharing options...
spurdy Posted November 23, 2009 Report Share Posted November 23, 2009 Everything like I said was replaced. OEM Bearing OEM Water pump Shaft & Impeller OEM Gear OEM pump cover OEM Oil seal The shaft going into the seal and bearing was a tight and snug fit, and the bearing turns fine, it turns over a little stiff like any new bearing. I just dont see how if you can slip the shaft in by hand, whats to keep the shaft from spinning inside the bearing. I know what you mean. It is crazy but everyone that I have had apart is a slip fit. Not even and interference fit. If I remember correctly the bearing is bathed in your tranny lubrication fluid. This is most likely what the engineers that designed this had in mind. You could always peen the shaft next to the bearing or over the inner race on the shaft to provide some interference. I have been running a stock impeller and stock gear in my latest banshee for almost 3 years now with no issues. However, when I tear down this winter to switch my tranny out I am going to revamp the clutch side with Brandon's parts and new cover. SP Quote Link to comment Share on other sites More sharing options...
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