OzVMX Forum
Clubroom => Tech Talk => Topic started by: g465b on October 07, 2011, 10:41:26 pm
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hi,can anyone suggest a cure ,fix,idea to deal with corrosion around the impellor on a 83cr250r
water pump.its 1-2mm deep from 7 to about 1 oclock around it,is araldite or a quick metal product
carefully applied a safe long term fix.what coolant is best to avoid further trouble.many thanks grant
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Hi Grant, I know some guys have used Devcon to restore the surface. I am pretty sure that any of the antifreeze/boil additives will help slow it down but draining it after a meeting would be the best bet.
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before it got too late or too bad I sent mine of to Geoff Morris - GMC - who did a proper repair for me and a good one at that.
Best of luck.
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thanks for the advice
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Used Devcon on mine, worked great no issues a couple of years later
Bets way to prevent it happening in the future, Keep riding it hard!
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devcon and the like aren't a permanent fix - eventually you will need further work and then they are a bugger to remove to do properly.
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devcon and the like aren't a permanent fix - eventually you will need further work and then they are a bugger to remove to do properly.
did you end up selling your 83 Ross?
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devcon and the like aren't a permanent fix - eventually you will need further work and then they are a bugger to remove to do properly.
The water sneaks around the back of the Devcon and continues nibbling away where you can't see it.
Sorta like termites.
You can end up with a real mess.
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yes I did MM - to a guy over east - just rang out of the blue. Apparently it didn't sell in WA because people thought there was something wrong with it because it was so cheap ???
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Grant,
My son and I have had the same problem with the pump cover on an 84 CR250 - we have used JB weld (similar to devcon) but actually hardens to be able to be shaped with a grinding tip - has held up pretty well and with the coolant we are using no further detioration of the case seems to be happening - we are using a 50:50 water mix with Motul coolant (blue) which was recommended - so far so good.
Barney
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paper mache
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Disstilled water must be used with any coolant tap water is no good.
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Magnesium forms a protective layer of magnesium hydroxide naturally however chlorides attack it. If the component is a magnesium alloy (guessing the Honda was) then any chlorides in the water (tap water) will attack the metal :o :o. Even if coated any small defect in the coating will make the corrosion very severe at the location of the fault. Advise to keep coolant as free as possible from chloride by using demin water is correct. Draining the coolant is also wise but any trapped water will continue to cause corrosion so drain when engine is hot and remove hoses etc to allow water to steam out.
If attempting repairs the advice is not to use wire brushes or other iron based implements to remove the corrosion and prepare the surface for repair as the iron can cause further corrosion under the repair. Magnesium was not the smartest choice of material.....but is sure is light!
My 87 510 Husky has magnesium cancer of the barrel and the water pump flat surface (the pump casing is plastic) but since its 24 years old and not holed yet it should last my ownership ;D ;D Later models reverted to aluminum alloy.
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many thanks guys for all the advice,spoke to the wiltec guys at mr vmx,they have used devcon on all their
water cooled CR hondas with careful prep of area and oats coolant ! Some great racing at mr vmx,for some
-I fell in first moto injuring my ankle,moto 2 hit a bike that went down right in front of me and tore my right
footpeg clean off,who needs two pegs when riding in sandy custardy slop.fun?