1986 CR125

The radiators are most likely clogged with magnesium debris. There is a vendor whose name excapes me , that can hot tank and rod them out. Someone will hopefully chim in with the name of the company?

I would look into repairing the case with the epoxy / jb weld method or shell out the $500 for a repop sold by Russel Australia.

I have a true survior 60 hr. '86 cr125 the case rot is just in the early stages, it is not leaking into the cases. I won't be risking it I'm waiting until after Xmas to get a Russel case and be done with it.

Also you want to run a waterless coolant like Evans etc.... The reactions of the other metals and magnesium with water is what causes the rot.

Thanks for your reply. I already have Evans Waterless coolant in it. I do not have any visible case rot with the exception of a tiny area that should not affect anything. I do have a slight oil leak. I think I will have to replace the case gasket. i assume that this means that I will also need another water pump gasket since the impeller will have to be removed to get the side of the case off.

Here is the bike as I got it.

Here is some of my progress.

Nice find, that was the bike to ride in 86. I would try and protect the magnesium housing to stop further corrosion because it will continue to corrode. Try and find some Belzona epoxy. Belzona epoxy is used in the oil and gas industry for all sorts of things mainly to stop leaks and prevent corrosion on piping, vessels etc. I have used it before many times in cylinder ports to raise floors, change angles and other uses. It is highly resistant to just about any chemical and has excellent pull off strength at over 3000 PSI. Once the part is prepped correctly and the Belzona is mixed you can actually take a stiff artist brush and paint the Belzona all over the prepped exposed magnesium as little as .010-.015" depending on what number Belzona is used. You would never have to worry about case rot again. Local hardware store epoxy's are not in the same league. There is a few down falls, it is pretty hard to find, it can be expensive and it is toxic to breath the dust if it is ground on and an approve respirator is highly recommended. It is worth looking into to save that precious magnesium cover. I sometimes can get it through a Belzona salesman MUCH cheaper then retail and may be able to help you out. If interested my email is james.falterman@yahoo.com

Thanks so much! I am using Evans waterless coolant now

NoMuff2Tuff wrote:

Nice find, that was the bike to ride in 86. I would try and protect the magnesium housing to stop further corrosion because it will continue to corrode. Try and find some Belzona epoxy. Belzona epoxy is used in the oil and gas industry for all sorts of things mainly to stop leaks and prevent corrosion on piping, vessels etc. I have used it before many times in cylinder ports to raise floors, change angles and other uses. It is highly resistant to just about any chemical and has excellent pull off strength at over 3000 PSI. Once the part is prepped correctly and the Belzona is mixed you can actually take a stiff artist brush and paint the Belzona all over the prepped exposed magnesium as little as .010-.015" depending on what number Belzona is used. You would never have to worry about case rot again. Local hardware store epoxy's are not in the same league. There is a few down falls, it is pretty hard to find, it can be expensive and it is toxic to breath the dust if it is ground on and an approve respirator is highly recommended. It is worth looking into to save that precious magnesium cover. I sometimes can get it through a Belzona salesman MUCH cheaper then retail and may be able to help you out. If interested my email is james.falterman@yahoo.com

Do you have a part number? I would like to order/try some. I have been using EPOX-A-LEAK=model CP-2 for years on cases with excellent results. I pick it up at refrigeration/HVAC stores. Bursting pressure 4000 psi for all refrigerants,aluminum,copper,stainless steel and all metals. Thanks mb

Right now I have the Belzona 1212 which is good for crack in metals. On there site they list quite a few used for corrosion protection, abrasion protection and chemical resistant for all sorts of uses. When I get a minute I’ll pull up the site and look

Brian_Bowles wrote:

Thanks for your reply. I already have Evans Waterless coolant in it. I do not have any visible case rot with the exception of a tiny area that should not affect anything. I do have a slight oil leak. I think I will have to replace the case gasket. i assume that this means that I will also need another water pump gasket since the impeller will have to be removed to get the side of the case off.

You do not need to remove the impeller to remove the clutch case, You do need to remove the 2 long screws that hold the waterpump outer cover on as they go through both & hold the case on, If you are doing waterpump repairs or seal/bearing replacement it is a good idea to undo the impeller before disassembly though as its much easier than trying to stop the shaft from spinning

The Belzona you want to use would be 1391, 1391T, or 1593. There are used in full immersion environments and higher temperature applications, that's the key. Pull off adhesion strengths are between 4,000 to 6,000 depending on which one. Temperature range is around 248F immersed and 392F dry. The cure time can be between 4 and 10 days and working life can be between 30-45 minutes. Hope this helps