February 2, 200917 yr Do all modern bikes with magnesium water pump housings have problems with corrosion and leaking like the Beta Rev3s? Looks like this is a major problem after several years?
February 2, 200917 yr Not just a problem after many years, we ran a 2006 Rev3 125 and it needed a new water pump casing under 1 year old! It had corroded to the point it was leaking coolant when standing in the 'batcave'. At first I thought it was residual water after washing the bike, then I tasted it and it was sweet tasting anti-freeze!!! Big John
February 2, 200917 yr Sounds like they didn't do much R&D on materials! Mag castings at least need to be put through a Chromate conversion process and then painted, or even better Hard Anodised to give the material half a chance of surviving. Do they fail around bolt hole more so than anywhere else? Galvanic corrosion can attack Magnesium quick too. Wayne.... Edited February 2, 200917 yr by wayne_weedon
February 2, 200917 yr At first I thought it was residual water after washing the bike, then I tasted it and it was sweet tasting anti-freeze!!!Big John Or French wine !
February 2, 200917 yr Author The two Beta water pump cases I have seen, came from around the impeller area and then causing a leak. I think many bikes use mag. cases from MX, enduro to trials. I was told that water in the coolant caused to corrosion?
February 2, 200917 yr Yes many bikes do use Magnesium, so the risks should be understood by the manufacturers Magnesium can be corrosion proofed in various ways. But it's nature means it will corrode badly if it's not dealt with. I machine a lot of it and in one example of 3d machining a billet small engine crankcase a few years ago, we even noticed the change in colour of the material machined at the beginning compared to the material cut towards the end of the 12 hour machining cycle. That was cut dry in a workshop with low humidity too. Add water and dissimilar metals in contact and the case worsens dramatically. Wayne...
February 2, 200917 yr Gday all, Coolant changes annually can help reduce the chance of this - water and anti-freeze in roughly 50/50 mix works for me. The anti-freeze also has corrosion inhibitor which is the important part. Do your car/van/truck while you're at it - it is the most common cause for engine failures in any vehicle - if that coolant is the colour of rust you're in trouble! HTH, Cheers, Stork
February 2, 200917 yr i'd state from the experience that i had with my beta that anti freeze actually made the corrosion around the impeller and lip of the casing worse to the point where with my new case i run plain water..
February 2, 200917 yr Author I was told by the Beta importer to use ONLY ELF 100% organic coolant to prevent corrosion. 50/50 was a no no. Anyone else heard of this?
February 2, 200917 yr A big factor in the corrosion is the ionic contaminants in the water you throw into the cooling system. Don't use tap water. Either use de-ionized water or one of the premixed varieties like engine ice or Maxima Pro-cool. They're cheap enough compared to an engine case. I have yet to see a corrosion issue on a Beta and I've had all of mine for at least two years and some up to five years. Don't use spring water either, it isn't the same as the de-ionized. My guess is that the guys with the big corrosion issues all used tap water that is rather nasty. Basically forming a battery by providing an electrolyte (contaminated water) with the magnesium as the sacrificial terminal and aluminum/steel for the other. It would be interesting to do a scan on the other components the coolant touches to see where that magnesium deposits. OK so I geeked out. Sorry.
February 3, 200917 yr Gday all, careful here that we dont confuse Corrosion with Cavitation. Cavitation around water pump impellers is almost impossible to do anything about and fairly common on many things. You can tell the difference as the holes remaining look "formed" and clean, corrosion in alloys always leaves that chalky residue. So far my 10 year old Techno shows no signs of either. Cheers, Stork
February 3, 200917 yr oh it wasnt cavitation in my engine caes . i think at the time i posted some pics on here..
February 4, 200917 yr Author Cavitation is the proper word to describe the problem, not corrosion. Thanks. I have noticed that most quality motorcycle coolants state; "50/50 cooland and de-ionized water to prevent cavitation".
February 4, 200917 yr wel bu***** me i stand corrected. the photos of cavitation erosion i googled certainly look like the innards of a beta water pump. however how does that explain the 'corrosion outside of the rubber seal that also looks just the same and where no water pressure woould be present.. i refer again to the photos i placed in the thread in 2006 i think..
February 4, 200917 yr That sounds like standard corrosion. I havent had a look for the piccys to be sure. Also, cavitation isnt preventable as far as I know, it happens when low pressures around the impeller effectively boil the coolant and bubbles eat the case. Its really a design thing. Someone might clarify that a bit better than me. Cheers, Stork. Edited February 4, 200917 yr by Stork955
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