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That water pump is a real horror show. I take it that you didn't flush out the engine's cooling passages in the early stages of the work? I'll give you one guess about what the inside of the radiator looks like.

I'm interested in seeing how the electric water pump does. I have contemplated similar a few times over the years myself but always got the original one working again instead.

The mechanical seal won't seal unless the impeller is securely attached to the camshaft and if you pressurize the water pump housing without the seal the coolant will flow around the end of the camshaft and exit via the weep hole so you will need to figure out a way to block that off that will hold the pressure. I have a vague recollection of someone machining a plug that was pressed into the bore for the seal.

The threaded end of the camshaft is a separate piece that is pressed onto the end of the camshaft. It is possible to heat the end and replace it. I think the end can be replaced with out taking the engine apart. The last time I heard Murrayf on cx500forum had some bad camshafts with good ends that he kept around for that purpose.

You referred to replacing the seal with the cup in place (commonly called the "Shep Method"). This is recommended specifically for CX500s up to a certain date of manufacture because they changed to a slightly larger cup (which requires a slightly larger bore) and the seals with the smaller cup are NLA. If you knew for sure that the bore is correct for the larger seal (GL500, all CX/GL650, some later CX500) you could pull the old cup out and carefully drive the new one in with the rear cover still attached to the engine but I wouldn't recommend it with the engine in the bike.

Actually the radiator and water pipes were all in quite good shape. Coolant drained after the engine had been run for a while was quite clean. Notice also the intake passages in the head, just visible in the photo. They are spotless, as if the heads had been done. True, I should have pulled the cover before installing the engine but that always means new seals and gaskets and not being familiar with the CX engine I gambled that it was OK.

Bob, I know you are correct about the weep hole. I think maybe JB weld will do the job and can then be drilled out if and when a new cam is installed. I will install a temp gauge and possibly remove the thermostat (not as important in Texas as in Canada!) since I don't have flow specs for the pump or know whether or not it will be damaged if the water flow is restricted by the thermostat. I had already ordered the mechanical and oil seals and the gasket for the cover so when the time comes those will be on hand. By the way, there is a Suzuki (or maybe Yamaha?) part that is identical to the Honda mechanical seal and available at about 1/2 the price. I can look it up if anyone is interested.

Easter wrote:Actually the radiator and water pipes were all in quite good shape. Coolant drained after the engine had been run for a while was quite clean.

Clean drainage doesn't guarantee the water passages are clear; it indicates the sludge around the waterpump may not be circulating and could still be lodged in various coolant passages. Sort of like arteries clogged with cholesterol. I seriously don't think the crud around the waterpump is exclusive to that part of the cooling system.

When I flushed my engine's water passages with a fairly high pressure/high volume water flow, I was very surprised by the quantity of sludge that came out... and I'm just talking about the engine itself, not the radiator.

Yamaha part #11H-12438-10-00

If you buy from the dealer they are about 2/3 the price of the Honda one. I just bought a seal for the GL1100 engine I'm working on (yes, the one inside the 'Wing water pump is the same as the CX/GL500/650 use) and didn't know when I could get to a dealer to pick it up so I shopped on eBay and bought this one https://www.ebay.com/itm/142263008659 which says it is a replacement for the Honda & Yamaha parts and a Kawasaki one too. It looks like it is wall made.

I'm wondering what the rest of the coolant system looks like - passages, etc. Seeing that pump, I'm pretty sure now it's definite that the the radiator needs the full service recommended above.

As stated before, the radiator is fine (except for the mentioned pin hole) and has had an acid bath before being painted. The water passages to the extent possible with a non-running engine have been checked. Certainly I will flush everything several times with clear water before putting the coolant in. Why would it accumulate in the water pump? I don't know, maybe the engine was stored for several years laying on it's back end? There probably is more crud in the system but after I cleaned out the water pump housing I blew air through the block passages leading into the pump and both sides were open.

Other than the bottom of the rad the water pump is the lowest part of the cooling system...

This was a basket case that is an assembly of parts, not all from the same bike. I know it had been in storage for some time.

After ordering the pump I changed my mind and ordered a cam, chain and assorted parts. If I were keeping the bike I probably would have given the pump a shot but just couldn't see turning it over to someone else like that.
So now the engine is out of the bike and partly disassembled while I wait for parts.

the question is stents vs a CABG

rcmatt007 wrote:the question is stents vs a CABG

Dang doctors.

desertrefugee wrote:

rcmatt007 wrote:the question is stents vs a CABG

Dang doctors.

Yes, I think the rest of us would relate better to some other comparison like "new wine in old skins" or a " shingle instead of a new roof" or some such.

meanwhile, parts have started trickling in but can't do much yet. Did replace the mechanical seal, just used my heat gun to soften the glue in the new one and with a couple of screw drivers, gently popped it out of the new cup and glued it into the old one which is still in good shape (and the correct size for the casting).

Time flies, I started this project in January and here it is May! I have skipped over some of the drama (since this is a family friendly site!) and say that "all is well that ends well" or at least I hope so. I ordered a license plate holder and a horn earlier this evening and that should wrap this project up. I even have an anxious buyer. Well, like my old boss used to say, " I will get excited when he shows up with the wheel barrow full of money"--and leaves it with me when he rides away on the bike.

A bit of summary is in order, so here we go. When last reported I was agonizing over the water pump and broken cam. A new- to-me cam arrived along with assorted items like cam chain, guide, O-rings, gaskets, water pump seals and impeller etc. The cam went in without too much trouble as I was able to loosen the head bolts but not remove the heads in order to free up the push rods. The cam came out the front of the engine. Needless to say the engine did have to come out of the bike for this exercise but even this is relatively simple when compared to the Goldwings. Unfortunately, once was not enough, after all was reassembled I found the shifter was not working properly so apart it came for the second go around. Turns out I had stretched the spring that holds the shifter shaft in place. Fortunately someone makes duplicates of the "no longer available" Honda spring. This time everything seems to be working. I have had two short rides (very short) down my street and back and except for a couple of minor issues that have now been resolved, we seem to be in business.

That ended up very nicely. I'm not a huge fan of the bobber look, but the CX is a nice machine from any angle and in any configuration. They have a nice sound, too! Sorry to hear you'll not get a chance to enjoy it much before it goes. Ah well. Other candidates await.

Came out really cool, love it!