Thread: Poor pumpbearing on Ultra pump!
03-05-2011, 09:40 AM #1
Poor pumpbearing on Ultra pump!
I recently pulled out my pump on my 260x beceause of spotted cracks in the pump-vanes. I'm new to this ski and was the first time I took it out. To my surprise I saw an old friend........this main pumpbearing 6303. I may be new to this forum and ski but has more than 9 years experiance in dealing with problems in other applications due to this bearing.
It's just a poor designed bearing that can not take heavy loads. Look at the heat-ring around the outerrim of the bearing. Also look at the shaved edges on the outer rim and you'll see that this bearing seized-up and spun around inside the housing of the pump. Yet when I took it out it was turning normaly whith smaller than 0.8mm of play either side(23 hrs and 23hrs for any bearing isn't normal, cmon!).
This bearing is spinning at such a high rpm that it is heating up, propably harder to turn(bogging down) and will ultimately cost you. Now you will say it's just a poor quality(brand name) and that a more expensive one would do the trick. NO, NO and NO! Been there, done that! As I said, this thing fails at even lower rpm's and according to me a poor bearing-design.
O and I know, my pump-shaft is still on the 09 specs. I see most of you hail the 2010 setup as heaven-sent. BUT I see it as double the trouble! If you have a double setup, then I agree that it would spread the load but will it lower your rpm's? That heatring is not beceause of load(too little play) but due to spinning at high rpm's. It's rated for more load than it recieves on this ski. No matter what the dealer tells you that thing can't take the rpm's. The play starts forming when the bearing heats up due to high rpm. The bearing-seal opens just a little and the dirty grease in the pump-housing, now full of metal-shavings, no also enters the bearing whith a snowball effect over a SHORT period of time. It does not matter if you put 3 side by side, this thing heats-up with high revolutions.
Maybe with the wetpump-setup it will have a better chance in doing it's job.
I grew tired of changing this bearing on the other aplications and changed it to this one in the picture. It did the exact same work on a diffrent make/model but lasted 4 times longer. Obviasly I'll have to modify this pumpshaft(on a brand new 260x bought in 2010 by the way) to the 2010 specs but wonders if it would be possible to modify to work with the wider bearing in the pcture. Side by side testing over 2 years proved it works 4 times better at achieving the same job. Beceause of the popularity and wide usage in the farming industry it's a much cheaper bearing too.
I know of someone who can't wait to bash me over this.......
03-05-2011, 10:17 AM #2I know of someone who can't wait to bash me over this......
You're gonna get it on this one
but seriously, does your wider bearing is hi speed rated? and how much load can it take?
03-05-2011, 10:43 AM #3
You're gonna get it on this one
but seriously, does your wider bearing is hi speed rated? and how much load can it take?[/QUOTE]
Don't know it's hi speed rating but know out of testing, the wider one last longer doing the same job. Feels tighter when turning, but should be with 4 rows of rollers. If I mod my pump shaft to take it, I'll prob will do a wetpump wiht 80w 90 oil. Will talk to a engineer I know on Monday. The wider bearing will need a pressfit-bush to correctly fit in the pumphousing. I've done it on the other applications and it worked, lower rpm's though.
That thing is smoking inside the pump to achieve that heatring and until someone installs a camera to verify, nobody knows for sure. Out of experiance I just don't trust the stock bearing. It's almost as if it were designed to only do x-amount of rotations and then fail no matter what the load and I have a box full of failed ones.
Bring it on....
03-05-2011, 10:58 AM #4I've done it on the other applications and it worked, lower rpm's though.
03-05-2011, 11:49 AM #5
Your'e right. I will do my homework on this one. Just think if it can take the rpm's, you'll only have to check pumpbearings every 80hrs. It just seems like somethings not adding up with the old bearing. Mine did not have that much wear, not even noticebale when moving up and down with impeller on. The only reason I noticed anything wrong was beceause the pumpvains cracked and I took it apart. Then noticed the heatring and concluded this thing can't take the hi rpm's. Till someone can give an educated opinion, slapping on to of the same bearings won't nececarely solve the pump bearings from failing if it's a hi rpm problem. And like I said, these stock bearings have an evil-spirit!
03-05-2011, 12:21 PM #6
03-05-2011, 05:24 PM #7
Bearings are everything, most of us will agree this bearing is a failed design. The pump shaft tunnel has limited expansion possibilities for bigger bearings. Good luck if you can improve it . Skat trak is the best solution at present I believe.
03-05-2011, 11:51 PM #8
With cracked pumpvaines, I'll be looking at the Skat trac as well. Everybody including Dave at impro's says however that the oem impeller is best. Will it fit?
Found an other bearing that can possibly be better: 7303CDB - I'ts a dubble row back to back arrangement for instant loads an rated at 20000rpms(grease) and 25000rpms(oil). Dimensions the same as stock. It also has the a higher load-ratings.
03-06-2011, 05:25 AM #9
good luck whatever floats your boat im happy with my modded pump its nearly done 100hrs trouble free, kawasaki have now copied it on the 300, i have heard of knowone ever having a pump issue from 2010 onwards, and yes your picture of the heat ring om nthe bearing is the same as we have all seen before.
03-06-2011, 08:56 AM #10
I'm not trying to reinvent the wheel or disrespect any of the veterans on this forums previous posts on this topic. I bet you it ain't the only thing Kawasaki copied from this forum!
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