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10/25/2009
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Edited Date/Time
5/10/2012 12:52am
I have both an 1988 and a 1989 Honda CR250. Both those engines have magnesium water pump covers with the well known corrosion issues.
I recently replaced the right side water pump cover on my 1988 CR250, the good news is that Honda now sells the water pump covers and they are made from aluminum!! No more corrosion issues.
I was at a vintage race today and I took a look at a couple of 1986 and 1987 CR250's. The right side water pump covers from a visual perspective appear to be the same as the 1988/89 water pump covers.
Does anybody know if a 1988/89 water pump cover will fit and function on the 1986/87 CR250's?
When I looked up the part numbers they are different.
I recently replaced the right side water pump cover on my 1988 CR250, the good news is that Honda now sells the water pump covers and they are made from aluminum!! No more corrosion issues.
I was at a vintage race today and I took a look at a couple of 1986 and 1987 CR250's. The right side water pump covers from a visual perspective appear to be the same as the 1988/89 water pump covers.
Does anybody know if a 1988/89 water pump cover will fit and function on the 1986/87 CR250's?
When I looked up the part numbers they are different.
87 was the first year of the removable clutch cover.
He can unplug maged up Honda radiators.
http://www.motorcycleradiators.com/
So let me make sure I understand you ThePipe. The water pump cover for the 1988-91 CR250 will also fit the '85-87 Cr250'S. You are also saying that Honda still has in stock the 85/86 water pump covers, but it has no quick access clutch cover?
Are the 85/86 water pump covers that Honda sells made of magnesium or aluminum?
So the best fix of all would be to order the water pump cover for the 1988/89 CR250, it has quick clutch access and would fit the 1985 to 1991 Honda CR250's and is now made of magnesium.
Did I get your post correct?
nine1seven, when the water pump corrodes plan on changing the following:
-clutch cover gasket
-water pump seals, both internal and external. You may also want to change the water pump bearings since the cover is off.
-gear box oil
-if you take the quick clutch cover access off, you will probably need a new rubber gasket (looks like a big "O" ring).
-plan on getting the radiators unplugged.
-it would be a good idea to check the coolant lines for magnesium stuck to the coolant lines side walls and to pull the head and cylinder and check the coolant galley ways for collected magnesium. So if you pull the cylinder, you will need a head and base gasket.
-SOME not too badly corroded water pump covers can be repaired, some use JB Weld. My feeling is that if the 1988/89 water pump cover will fit the 1985 to 1991 water pumps for the $180 or so for an aluminum water pump cover would permanently fix this issue. Who knows when Honda will discontinue the water pump cover.
The Shop
By the way, the new aluminum water pump cover had some sort of clear coating in the pump area. I also use coolanol as my radiator coolant.
Kevin
http://www.thumpertalk.com/forum/showthread.php?t=777165&highlight=
That weep hole when coolant gets in between the seals, to leak out and let you know there is a bad seal (or bad impeller shaft).
OEM parts schematic and check if the part numbers are the same for the year model or they have been updated.
I am waiting for a new head gasket and hopefully it solves my water issue.
I have replaced the cover and all the internal parts.
I was told if the bike at any time over heated it could have developed a small head gasket leak which could buid pressure in the water system and force water past the seal. Hence water comes out the weap hole
Kevin
JTR wrote: Well now and managed to repair the clutch cover with Nural 21 is great,
does anyone of you know anything about Nural 21 and were to buy it
http://lubricationspecialist.com/front/showcontent.aspx?fileid=21&gclid…
Pit Row
If you find corrosion in the WP area one MUST check the radiators. The corrosion gets stuck in the rads & plugs them up. Have them ultrasonically cleaned or ship them off to Mylar's in Utah.
I have used JB Weld with great success. Media blast the area with old the seal in place & flow in the JB. Use a Dremel to shape to your taste. Rebuild with new bearings & seals. While your at it lap the gasket surfaces.
No need to coat the impeller area with epoxies. As another poster said use Evans coolant. Late model ATV have the same problem as we do & all the dealers carry the coolant. If not Ck this link out:
http://www.evanscooling.com/npg-2/
I have been using this coolant for 2 years now. NO corrosion issues. Guaranteed. Plus a lower operating temp.
Yes the 89 case is still available from Honda. My friend HAS put a 89 case on a 86. I am about to but have not got around to it. It can be done. Should fit an 88 with no probs (my guess).
The 81 case will fit the 83 (and 82 I think) motor. Its tight with the rad hoses but I have seen it done. I am actively looking for a 81 case as we speak for a back up.
I have a couple cases that I think are too far gone for JB. I would love to find somebody that can weld magnesium. I know it can be done. I have not found the right welder yet. Anybody have a line on a good welder?
Blue Skies
Stan
WV
My pump is rotted out and there discontinued parts? Be lost on what do do?
Cheers Harley.
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