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bogie52 04-09-2013 10:17 AM

ktm water pumps
Probably everyone here has heard that the water pump on the 950 and 990 twins should be replaced at about 12k miles. Let me share my experience with my '05 Adventure. Back in 2010 with almost 10 k on it I had the misfortune of running into a U-turning car. I went over the bars and car but was OK. The bike was called totaled- It needed a frame, a radiator , a front rim and some expensive plastics like a fuel tank. The other drivers insurance paid out and I bought all the pieces and put my pretty black girl back together ! I really love that bike and especially that paint job.
When I removed the bent radiator and drained it an amazing amount of sand or grit came out-almost a teaspoonful! I would guess that was from the casting process and had not been cleaned prior to assembly at the factory!
I put on about 4000 more miles, it was winter and so a good time to change the water pump on general principle- it was not leaking. The parts you are suggested to change include the impeller, its shaft and bearings and the seal. The kit of parts I bought from KTM Twins supplied a new type of impeller-presumably better- the vanes are shaped differently. The installation is no problem but I do have a lift table-I would not care to do this job on the floor. The shaft did show wear at the seal's point of contact, perhaps deeper than one would expect at what on most engines is a low mileage.
My guess is that at least back then the factory built engines with grit still in the cooling passages and that grit would easily account for a higher wear rate in the pump. There is no filter but the lowest part of the radiator is where gravity would let the grit settle. Probably the finer bits just keep circulating around forever.
My suggestion to all would be to remove the whole radiator and fan assembly -its not that hard-the next or first time you check the valves-and drain and flush it upside down. Flushing the engine while the radiator is off would also be advised, then reassemble with fresh coolant. My guess is that will prevent early water pump failure and that is how I am treating my other two KTMs, an 06 SM and an 08 Superduke. Removing the radiator really makes checking the front cylinders valves a lot easier too.
If the pump does leak the fear is that the water will get into the oil, clog the paper filter and damage the engine from lack of oil flow. As a precaution just in case of a pump leakage I am using the stainless steel cleanable filter from Scotts. That way if water gets in the oil I'll see foam in the oil and deal with it but not have a collapsed filter. I hope this helps and I will be watching to see your feedback . I am especially curious if there is a year when the factory started to do a better flush job or if this applies to their other engines as well .

gefr 04-09-2013 12:08 PM

About the new type impeller.
The new assembly includes a longer shaft, made of a darker steel. The new type impeller should be matched with the new type pump shell. I am in need of a wp replacement as I noticed the coolant disappearing slowly without any apparent leak. I will mount the older type shaft since I have it on the shelf and keep the old impeller and wp pump shell.
My bike is a 990, has 50k kms and was made in 2006

corndog67 04-09-2013 02:06 PM

What's a darker steel? Parkerized? Hard chromed? Teflon coated?

gefr 04-09-2013 10:42 PM

I believe it is hardened. I have no more info.
This is just a guess. I do not know anybody that tested it. No teflon coated for sure.

pdxmotorhead 04-09-2013 11:06 PM

The CJ shaft looks and sounds like a piece of tool steel that's been hardened. Think cutter bit.. It rings like a bell when tapped. :) The surface is also very very smooth.. Much nicer than any part of the one I took out..
the machine work is premium...

No interest other than a impressed customer..


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