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Discussion Starter · #1 ·
All, I would really appreciate anyone's advice that knows their stuff when it comes to the cx500 engine. I had my mechanic runs a compression test (amongst other things) on the bike I purchased this week and he sent me the following information:



COMPRESSION TEST



RIGHT CYLINDER - 140 psi



LEFT CYLINDER - 160 psi



lEAKDOWN TEST



RIGHT CYLINDER - 40% MAINLY THROUGH THE RINGS



LEFT CYLINDER - 12% MAINLY THROUGH THE RINGS



Should I just drive it and consider tearing her down next winter or could that further the issue and even worse manifest into something else? I could afford a rebuild however, he said he couldn't make any promises when it comes to new rings resolving the issue. Something about the pistons could be out of spec and then new rings wouldn't fix the problem. What should I do? -A
 

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All, I would really appreciate anyone's advice that knows their stuff when it comes to the cx500 engine. I had my mechanic runs a compression test (amongst other things) on the bike I purchased this week and he sent me the following information:



COMPRESSION TEST



RIGHT CYLINDER - 140 psi



LEFT CYLINDER - 160 psi



lEAKDOWN TEST



RIGHT CYLINDER - 40% MAINLY THROUGH THE RINGS



LEFT CYLINDER - 12% MAINLY THROUGH THE RINGS



Should I just drive it and consider tearing her down next winter or could that further the issue and even worse manifest into something else? I could afford a rebuild however, he said he couldn't make any promises when it comes to new rings resolving the issue. Something about the pistons could be out of spec and then new rings wouldn't fix the problem. What should I do? -A
ride it,enjoy enjoy it.let the guys here decipher what is really happening.i cant see you can do any damage by riding it.

what does he mean....mainly thro. the rings,does he suspect another leak,or is it a phrase
 

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Has the bike been sitting for a while. If so, I'd drive it - you could simply have a sticky ring that will loosen up with use. Check it again after a while. I don't think you have too big a discrepancy between both cylinders to warrent a tear down right now. A 20psi difference wouldn't bother me. It would be different if you were talking 100psi in one and 80 in the other both of which is way less than the spec of ~170 if my memory serves right..
 

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I've seen these bikes run quite well with 110 psi in both cylinders - your engine is near new. I'm guessing with some regular running, and oil changes the rings will loosen up, and provide years of good service. How does it run now? If not obvious problems keep on her and ride!
 

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missed your first few posts,id just like to say welcome.i see you got your location in your avitar,good idea to put your your bikes details into your signiture line
 

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I bought a GL500 a few months back and at that time is showed 110 and 120 psi. (I should check it now - maybe I'll do that and report back) It runs great all the way to 10K. I've put about 3,000 miles on it in just over two months and I'm not even considering a rebuild. I bought a 2nd bike that has been sitting 13 years and it shows about 70 psi but I have not started this one yet as the carbs are off now for cleaning. I'm betting once I run it some the compression will come up.



Bottom line is if it runs good don't worry too much about it.
 

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Discussion Starter · #7 ·
All, Really appreciate everyone's feedback. I was bumming when I got the call from my mechanic. My objective when I bought the bike was to eventually cafe it out and I budgeted $500 to get new tires, fluids changed, new handle bars (Daytona's) installed, brakes redone and whatever else recommended by the shop. Next year another $500 for a tank and seat.



If I was able to get to the end result spending less than $3K I would be well ahead of what I was originally considering for my purchase--new Moto Guzzi v7 classic ($7K). I would normally purchase new so I don't have to worry about stuff like this. And when I was told about the compression test I was starting to regret my decision. But I'm all good right now.



PS., Felt like I finally became a man when I bought the CX500 --been riding a vespa for the last 3 years because the wife thought it was somehow safer.
 

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Long "Road Trip" should fix her up. Change the oil and filter before you go, and when you get home. Very rare to have ring problems with a CX. Obviously depends on who/when/how you or PO (previous owner) has ridden her.



These bikes are superb tourers, especially when two-up. Take the wife with you, ride 2 tanks in whatever direction takes your fancy, stay in a cheap hotel, (hubba, hubba) and then 2 tanks of fuel back home. Open her up on the highway, to vary your speed and engine load a bit.



Should get mega-miles out a CX/GL. without need for tear down. One reason we all buy them, and there are forums in almost every country of the world.



Stay shiny side up. Bear.
 

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Ride it. I'm at 100psi or so on both cylinders and doing fine. And my pistons were locked solid when I got the bike. For all I know not all my rings are free moving. But I don't see a problem with what you have.
 

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I would normally purchase new so I don't have to worry about stuff like this.



A few $$ here and there and they will outlast about anything, far past the warranty period of a new bike.
 

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Remember mechanics like money too. Some shops overly influence their mechanics or parts people to push for things that aren't needed.





I once tried to get an oil change from this quick lube that was part of a car dealership. First thing they did was check my air filter. Oh my it was dirty. Well they stopped to show me the air filter and said that if they didn't replace it they couldn't warranty the oil change. Told them I didn't care what the filter looked like. And they followed up by saying they couldn't do any work that they couldn't warranty. They put the filter back and I left.



They wanted $24 for the air filter about 10 years ago. I was working at walmart that summer and replace it for $6.





Then I went home to tell my roommate that the shop he was a service manager to wouldn't change my oil. I got my next two oil changes for free.





So take the information that the shop says and consider it as a recommendation. Then come to us and ask if it's needed or how to do it. Eventually we would like you to do your own work if you're able. These are very simple bikes so even the most unskilled timid people should be able to do there work.
 

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I agree with all of the above.You have nothing to worry about.The theoretical 170 Psi is the top limit.Even the service manuals give a bottom limit of 150 Psi but there's loads of CX/GLs running around well below that and no problems.

One of my engines is @ 170/162 Psi but only because when I built the engine I used new rings and glaze busted the cylinder walls and the bores were well within spec even for a high mileage engine.

The engine will benefit from changing to cheap 15w40 diesel engine oil as it's much more robust than normal gasoline engine oil.Many UK bikers have been using this for years.



Click here,



http://www.pdsrecording.site90.com/cxgl500/OilChange.htm



and change the oil and filter between 3,000/4,000 miles
 

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I once tried to get an oil change from this quick lube that was part of a car dealership. First thing they did was check my air filter. Oh my it was dirty. Well they stopped to show me the air filter and said that if they didn't replace it they couldn't warranty the oil change. Told them I didn't care what the filter looked like. And they followed up by saying they couldn't do any work that they couldn't warranty. They put the filter back and I left.



They wanted $24 for the air filter




Only $24? I know a guy that fell for that stuff and ended up with a $125 bill for a simple oil change but they told him he needed windshield wipers too. I just take the oil and filter of my choice to a local service station (yes, a few still exist) and for $15 they do it while I'm underneath the car checking out other stuff. I used to go in there on a Sunday when all they've got is an oil change jockey and for a $10 tip I get to use one of their lifts and tools to do hours worth of work if I needed to but of course they know me and that I'm ASE Certified. My daily driver hasn't really needed anything that I could do myself so I paid something like $1,100 to the dealer last year just to replace the power steering pressure hose then a week later the alternator. Both jobs involved dropping the engine cradle and for the alternator the right front suspension has to come off then it needs a complete front end alignment which they didn't do exactly correct. When I get to feeling better it's oil change time again and I'm going to toe out the left front by about 1/2 turn on the tie rod as looking at the tires they didn't get it exact.



Ah well, I'm just going to rotate the fronts to the rears soon as at 45K on those tires and the way I drive it tells me it's about time despite having plenty of tread left. If you want a good car tire http://www.tirerack.com/tires/tires.jsp?tireMake=Bridgestone&tireModel=Potenza+RE960AS+Pole+Position will last 60K easily on most cars provided your suspension is balanced and everything's in line. Grip like you wouldn't believe, even in rain, snow and ice.



Hey, looked out the window and we've had a tiny dusting of snow during the night, send more down here!
 

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I agree with all of the above.You have nothing to worry about.



The engine will benefit from changing to cheap 15w40 diesel engine oil as it's much more robust than normal gasoline engine oil.Many UK bikers have been using this for years.


Agreed across the board. That old 1965 Mercury 6-cyl inline I had in my boat was way down from factory specs but all the cylinders were fairly close especially for a 2-cycle engine. 90 HP was still 90 HP because it would compress the air/fuel mixture just fine.



When a cylinder fires the rings expand a bit thus it isn't an issue until you obviously start burning oil. The rings on these bikes, if not abused by using the wrong oil or running them out of it, can last a good 300K miles. A good oil such as Shell Rotella 15W-40 changed on a regular basis will also extend your cam chain life because it's meant to put up with the high forces encountered in a diesel engine. There's a reason that the owners of the big semi truck tractors use Shell Rotella or Mobil Delvac. It still has a fairly high zinc content and is highly refined, those companies can't afford to cheapen up on their oil and lose their reputation as a semi driver expects to go anywhere from 500,000 - 1,000,000 miles before he has to have the engine overhauled.



Change it often and while you can probably use the filter over once the darn things are cheap and easy enough to change, just make sure that the washer isn't lost that keeps the spring from digging into the filter base. Darn thing tens to hide on the old filter and many find that a PO has accidentally tossed one out with an earlier filter. Since these were used on a ton of their bikes getting a new washer is probably a simple trip to your Honda dealer or you can always call people like TAS and they'll have one as well as cutting you a deal on a 3 pack of filters, new filter bolt or drain plug bolt + washer.
 
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