There seems to be some question as to whether this is actually an upgrade or not, but I was putting in a CJD Super Shaft anyway, so why not? The factory engineers must have some reason to have changed the design. I ordered the 2009 impeller and cover, and the "long" Super Shaft from CJ. The long and short shafts are really only about 1mm different in length- I expected to see a thicker impeller to match the longer shaft, but................. The 950 pump cover. The arrow shows a reference point to gauge the height of the cover- I was surprised to find the 990 cover actually had less deck height than the 950 part- Because the 990 impeller is actually thinner than the 950 impeller, even though it's hub is 1mm thicker- So where is the improvement over the old pump? It appears that the 990 impeller has anti-cavitation style vanes, typically more of an improvement at higher rpm- If there is any benefit from the 990 pump, it will probably be undetectable, but it's always interesting to try something different. I'll admit to being a sucker,(when I was younger and more foolish),(well, younger anyway), for an ad that promised "Up to 10% More Horsepower!" A friend who does Ducati dyno tuning pointed out that such an ad really doesn't promise anything, except that you won't get OVER 10% More Horsepower. Some day I'll learn.
i'd really like the CJ shaft (and some other stuffs) But the shipping cost is just a bit to mutch for me...
there was discussion related to this subject some time ago, "should I 'update' a 950 engine with a 990 pump impeller and cover?'. There was a supposed 'unofficial' view/response from a KTM engineer or something to that effect, that it was NOT recommended to perform this alteration to the cooling system on a 950. As I recall the reasoning was that the cooling passages on the 990 cylinder and head are different. When applying this change to the 950 (the change to the pump increases flow rate) there may be problems/issues related to coolant flow through the head.
That is some interesting info, Ken. I like the "supposed, unofficial" qualifier, that the passages are different. I don't doubt they are, but the 2007 990's have the old style pump. I wonder what kind of issues will occur, due to the increased pump flow? I'm guessing there will be no noticeable difference, but I like the idea of increased flow at lower rpm, where I have the most overheating problems.
I did it. Seems to work ok. The thermostat will ensure the motor runs warm enought. So far as cooling goes...... Improving the air flow to the radiator, through airodynamics makes a big improvement.
It may be a coincidence, but after upgrading (I had parts - came with the bike) and replacing water pump seal many hose connections started to leak. Within 3 weeks after replacing. It's 7 years old etc, but almost all of them leaking now. So, may be pressure did go up. It's cold now, so its hard to judge if it runs cooler.
Contact them before the next shipment to add them in..... Gabe's a great guy to deal with. Tell him what you want to see.
I want to share one related experience with the larger water pump. The temperature with my oem 2006 950 always went forth and back between 4 and 5 bars on the display when idling. When summer days got hot (yes, I know this is not Arizona or Africa) the few single days, I saw occassionally 6 bars on the display to my dissatisfaction. After replacing the motor with a 2009 990SDR (with 28 instead of 25 mm tube on the pump suction) and with the same temperature sensor that I moved from the 950 to the 990, I have never ever seen more than 4 bars on the display! What else? The valve clearance on the exhausts in my old 950 changed considerably with need to change the shims one step and sometimes even two each winter service (every approx. 20000 kms = 12.5 kmiles). After two summer seasons with the 990 motor (40000 kms and exactly the same kind of torturing of the motor) I just changed the 4 exhausts shims to one step thinner, but that was a borderline need only. My conclusion: The 990 (at least my 2009 990) maintains a much more stable temperature than the 2006 950 did. One consequence is that you hardly need to check the valves. I tend to believe I will get much longer life out of my 990 motor than I did with the 950. Note: Of some reason KTM went back from 28 mm tube to 25 mm some one or two years after 2009. Just wonder why.
I believe there was something wrong with your 950 motor, these temperatures are not normal. Regarding your note, there is an optimum mass flow rate for every rpm region and tube diam regulates just that.
