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1981 Honda CX500C
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Discussion Starter #1
I am looking for a running motor for around 350$. The motor I am looking for is a 1981 Honda CX500C. I am located in corvallis. Please let me know if you have one available.
 

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1981 Honda CX500C
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Discussion Starter #2
My budget is 350$ and I am looking for a running 1981 Honda CX500C engine. I am located in corvallis, but the engine is going to Newport. I can pickup if your within 10 miles to corvallis or newport. Or we can meet halfway.
 

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I have merged your threads. Please do not post the same thing in different parts of the forum because it only causes confusion when people answer in both places.

The engines in all CX500 models from '78-'81 are the same so you don't need one from the exact same model and year ('82 CX500Cs have the later version with a different ignition system).

Having replaced engines myself a couple of times I understand that sometimes it is better to go that way but what has happened to your old engine that makes you think it has to be replaced?

BTW: Welcome to the forum. Please add your location to your profile and your bike's model and model year to your signature so that you don't have to remember to tell us every time and we don't have to keep asking when you forget (see Forum Settings link in my signature).

And welcome to the world of antique vehicle ownership (they own us, not the other way around). Your bike is about 4 decades old and the Previous Owners may or may not have done the maintenance necessary to keep it safe & reliable so before you start using it it is highly recommended to download the Factory Shop Manual for your model (available through the CX Wiki - link in my signature) and go through all of the service procedures, regardless of whether your bike has reached the specified mileage.
I also recommend looking on all rubber parts with suspicion because rubber does not age gracefully. Check the date codes on your tires and replace them if they are over 5 years old no matter how good they look & feel (old rubber simply cannot flow around the irregularities in the asphalt well enough to grip, especially if it is cool or wet). If your bike still has the original rubber brake line(s) (should be replaced every 2 or 3 fluid changes = 5 or 6 years) I recommend shopping for modern stainless braided ones (they last practically forever and double the life of the fluid). And don't forget things like the rad hoses and the boot between the engine and swingarm (they can crack on the bottom where you don't see it).
 

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1981 Honda CX500C
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Discussion Starter #4
Thanks. It was my dads and we got it running, but he blew the engine redlining it. I didn't know anything about motors back then. Since then I have done a ton to the bike and I am building a non street legal build. I had the transmission block in a machiene shop and I would rather just buy a new motor rather than have the 650ish dollars of work done to the one I have.
 

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1981 Honda CX500C
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Discussion Starter #6
I dont know. It was the first time it started after 12 years. We changed all the fluids and after about 9 minutes of redlining in neutral, the valves broke off and bye bye engine.
 

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I dont know. It was the first time it started after 12 years. We changed all the fluids and after about 9 minutes of redlining in neutral, the valves broke off and bye bye engine.
Why would you redline any internal combustion engine in neutral? And for nine minutes? You should definitely not do that to your replacement motor when you get it.
 

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That sounds a lot like an event at a charity rally I used to go to. The subject bike (donated by a bike wrecker) would arrive on site with all the fluids drained except a bit of gas in the tank. Tickets with times on them were sold during the afternoon and at the appointed time they would fire it up, lock the throttle wide open and let it rip. The pot was then split between the charity and the person with the ticket closest to when the engine stopped.
IIRC, the year it was a CX it set a record........
 

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Discussion Starter #11
Why would you redline any internal combustion engine in neutral? And for nine minutes? You should definitely not do that to your replacement motor when you get it.
I didnt do that. My dad did and this was about a year ago when I knew nothing about engines. Believe me I would never do that.
 

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Yeah, the H1 is a 2 stroke so if there was oil in the gas it would run a long time. The CX with no oil or coolant ran for about 15 minutes IIRC. And after it died it was rolled to an area where Harley guys were camped and they paid $ each to hit it with a baseball bat.
And these days we get accused of "Harley bashing" if we comment on how much better Hondas are designed. My how times have changed.....

Anyway, good luck finding an engine in your area.
 

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1981 Honda CX500C
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Discussion Starter #15
Yeah, the H1 is a 2 stroke so if there was oil in the gas it would run a long time. The CX with no oil or coolant ran for about 15 minutes IIRC. And after it died it was rolled to an area where Harley guys were camped and they paid $ each to hit it with a baseball bat.
And these days we get accused of "Harley bashing" if we comment on how much better Hondas are designed. My how times have changed.....

Anyway, good luck finding an engine in your area.
Thanks. I keep finding some on ebay but shipping is outrageous.
 
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