Honda CX 500 Forum banner
1 - 20 of 21 Posts

·
Registered
Joined
·
28 Posts
Discussion Starter · #1 ·
Anyone know of the best place to start looking for water getting inot the oil? My first guess is head gasket, but maybe there is something common to these bikes??? Bummer. This is a bike that has been sitting for a looooong time, and I am just getting it going again. Thanks Zeph
 

·
Registered
Joined
·
190 Posts
Is there also oil in the coolant overflow bottle and/or radiator?



And.... what is the year and model of the bike?



Hoppy
 

·
Registered
Joined
·
2,601 Posts
Make sure someone hasn't plugged up the weep hole under the water pump to try and remedy a leaking mechancical seal. If they have then the presure builds up and seeps into the oil.
 

·
Registered
Joined
·
28 Posts
Discussion Starter · #5 ·
Thanks guys, it's a 1980 CX 500D. As far as I got today, it was running hot, and foamy oil.
 

·
Registered
Joined
·
639 Posts
My '81 GL500 sat for eleven years before I bought it. Once I got it running, the mechanical seal went bad. Within 6 months, the left head gasket went bad. One month later, the right head gasket blew. Replacing the head gaskets is a piece of cake even for a newbie. Replacing mechanical seal is fussier but still, a newbie can do it.



If your oil is the color of a chocolate milk shake, don't run your motor. I blew out the big end of a CX500 by running it with water mixed in the oil. One day, the temp gauge read high so I put more water in the radiator. Rode maybe 8 miles. A few days later it was the same thing -- temp gauge read high. Added more water to radiator then rode 25 miles north. On my way back, at 60 mph, the motor ceased. No it didn't lock the rear wheel but instead it felt like the back brake being held on right before the point of skidding. Brought cycle back home on the back of my truck. Pulled motor and yikes, crankshaft bearing were shot. My oil was light tan in color. Prior to my engine melt down, motor was low mileage and in great shape.



I've been on this forum for several years and it seems that 70% of the time, water in the oil is due to mechanical seal failure. When my head gaskets went bad, I was using up coolant by burning it in the cylinder but it never got to the crankcase.



Year after year in middle school our children are taught that oil and water don't mix. Jeez, the experts who write the science text books have obviously never heard of Honda CX/GL500's. In fact, water and oil do mix nicely in the crankcase of these bikes.
 

·
Registered
Joined
·
28 Posts
Discussion Starter · #7 ·
I just got it going, I'm not smoking out the exhaust, just foamy oil. I know not to run it. I will do the head gaskets for good measure, but what is the "mechanical" seal? Thanks Zeph
 

·
Registered
Joined
·
28 Posts
Discussion Starter · #8 ·
I found the mechanical seal, the crank coming through to the H2O pump. I found a Honda service manual online in pdf form for the CX 500, I'll figure out how to post the site.
 

·
Registered
Joined
·
2,601 Posts
Don't go thinking you need to pull the engine to replace the mechanical seal, there's a procedure we commonly refer to as "Shep's Method" that doesn't involve dropping the engine at all, pretty easily done and thre are a variety of sources for the seal. That is, of course, if the weep hole is plugged, if it isn't however don't despair. Someone around here has pix of where the weep hole is, it's rather hard to find, but it relieves the pressure from the leaking seal so it doesn't backtrack into the crankcase.



For now change the oil and filter, find those pix of the weep hole and make sure it isn't blocked by running a piece of guitar string up through it.



When changing the oil filter don't lose the washer that sits between the spring and the filter element, it often sticks to the filter and you can't see it.



Any by all means don't hesitate to ask questions and post pictures, there's a weath of knowledge around here almost 24x7 and also on a couple of other websites. We'll work you through gettting it back into top shape in no time but get the oil/water pinpointed first.
 

·
Registered
Joined
·
2,601 Posts
http://drop.io/CX500_GL500 hopefully this will get guys to the manual.


I believe it was someone on this forum that started that website so we could consolidate and exchange info in one place. There's also an excellent thread stuck to the top of the General foru.
 

·
Registered
Joined
·
190 Posts
The below engine ('78) also sat for a "long time" and this is how crusty it looked externally even after a spray down with mineral spirits followed by Simple Green/water. Actual mileage was said to be 6000. Internal inspection actually supports the claim. It is salvageable. The bores are very good plus and cross-hatch hones marks are still visible although they don't show in the picture. There was no debris in the oil pump pick-up screen or laying in the bottom of the engine. Almost no sludge. Check out the water jacket area!!! There was similar build-up in the coolant passages in the heads.







You may find similar nastiness. This is not to discourage you from rebuilding but just to give a heads-up as to why one should not run (and possibly eventualy destroy) an engine that shows signs of severe illness.



The next picture.... there was corrosion and pitting on the camshaft that had destroyed/abraded the oil seal's contact lip forward of the water pump mechanical seal. The cam had to be dealt with. It was removed, aft/wtr pump end chucked in a drill press (fwd/tapered/fan end was supported in a block of wood with a hole in it...clamped to drill press table). The cam was spun and fine grit abrasive paper and crocus cloth was used to polish the oil seal bearing surface. When examining things pay attention to surfaces where oil seals contact. If they are rough they will destroy new seals.







Good luck with whatever you decide to do.



Hoppy
 

·
Registered
Joined
·
639 Posts
HotFoot, that's one spectacularly crusty motor. Looks like some renegade slime mold from some secret Michigan genetics lab invaded your motor.



That's good advice on the camshaft. Last time I replaced a mechanical seal, I did a Walmart version of fixing up the camshaft. Instead of removing it, I merely used a small piece of sandpaper in my fingers to clean up the surface where the oil seal contacts. I think my motor was in better shape than yours to start with however.



The great thing about these bikes is how repairable they are people who aren't mechanics. I mean, there's no other bike that I know of where you can pull the motor in 45 minutes.
 

·
Registered
Joined
·
28 Posts
Discussion Starter · #14 ·
Finally got back to the motor a bit. I have water in he oil, but no oil in the water. The weep hole was not plugged. The Mechanical seal looks different than I was excpecting It looks like a stamped metal hoochie that fits snuggly around the camshaft. Is there a rubber seal inside that? There i also the seal with the attached spring, which I'll go ahead and replace also. I hope it's that mechanical seal. Any input?? Thanks Zeph
 

·
Registered
Joined
·
2,282 Posts
The metal hoochie (I finally learned the name of that thing), is where the seal with the attached spring goes. I have changed out 4 of these just using "Shep's Method" of not removing the hoochie, but simply removing the new spring part of the seal from the new cup and using silicon (I used Hondabond II) to seal it into the old hoochie. Then the polo mint,(white Lifesaver)goes into a rubber sleeve in the back of the impeller. I also dabbed some silicone in there too before I inserted the rubber sleeve over the polo mint.



Just make sure that when you place the spring seal into the cup that you align the cutouts on the seal with the tabs on the inner part of the hoochie. You should be able to press the seal down level with the end of the sleeve. Those small holes between the camshaft and the sleeve is where coolant escapes to the weep hole area if the seal is leaking. The actual seal is made between the black ceramic end of the spring seal and the end of the polo mint. That whole area is awash with coolant when the bike is running and the coolant is also at about 13 psi. That is why you need to do the silicone, it keeps the coolant from going around the end of either seal.



Also is is wise to lubricate the seal surfaces with liquid soap or coolant so that the two surfaces don't start turning dry. That could ruin the seal or even pull out the siliconed ends.
 

·
Registered
Joined
·
28 Posts
Discussion Starter · #16 ·
Thanks Blue Fox, I saw the tabs on the hoochie inner sleeve. I bumped across the Shep method in the old forums. Any idea where is the best place to get the new seals? Other than Honda of course. Good thing we got the terminolgy cleared up. When I took my impeller off, the seal was already loose from said hoochie.
 

·
Registered
Joined
·
2,282 Posts
At one time, Boats.net had the best prices on a Yamaha seal that is identical. I just looked a couple of weeks ago, and they went up in price from $14 a year or so ago to $21 now. Plus shipping. I think Doward at one time was getting a bunch ordered. I don't know if he still has any. I know Rickbert will be needing one too in the next week or so, maybe you guys can get a quantity price from someone.
 

·
Registered
Joined
·
639 Posts
Zeph, glad you got your water/oil mixing issue diagnosed. Yes, if you remove the water pump cover, acorn nut, and impeller, and you see a spring, that does mean your mechanical seal is bad. And if the rubber accordion falls out in your hand, that also means the mechanical seal is bad.



That rubber accordion is officially called the mechanical seal and is what you'll be replacing. Many of us on this forum have replaced it with a Yamaha mechanical seal solely because the Yam costs $15 ~ $20 USD compared with nearly $70 for the official Honda part. I've not heard of a lick of difference in performance between the two parts.
 

·
Registered
Joined
·
5,563 Posts
Thanks Blue Fox, I saw the tabs on the hoochie inner sleeve. I bumped across the Shep method in the old forums. Any idea where is the best place to get the new seals? Other than Honda of course. Good thing we got the terminolgy cleared up. When I took my impeller off, the seal was already loose from said hoochie.
zeph,here is the part number you require......Note:If you use the Yamaha Seal(Part No:11H-12438-10-00) the glue they use is harder so heat underneath the metal cup until it sizzles and be careful and don't force it


and step by step instructions,with photo,s http://www.sheppola.karoo.net/TwistedTwin/MechanicalSealInBike.htm
 

·
Registered
Joined
·
2,601 Posts
With two pairs of needlenose in hand, I dropped mine metal part down into a hot skillet for a bit and kept gently testing until it came out perfectly. You definitely don't want to overheat it or underheat it or it could ruin the rubber part. If it takes more than 15 or so seconds then remove it, let it cool and turn the heat of the skillet up.



Obviously there are many ways to do it so whatever floats your boat. :)
 
1 - 20 of 21 Posts
Top