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Discussion Starter · #1 ·
So I have an 1982 cx500c and the crank and rod bearings were bad in it. So I need a new engine and I have found a 1980 cx500. My question is will that engine fit into my 1982. If it will fit is the wiring going to match up or did they change things between these years. If nothing else works will the crank at least be the same? Thanks for the help guys.
 

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The motor will work, but your going to have to change the stator and flywheel inside the engine as well as the rear cover. Your 82 has a TI ignition and the 80 motor has a CDI ignition. While it's apart you should change the mechanical seal and oils seal, check the timing chain and tensioner too. To do this you will need a rear cover gasket at least.

It's not a hard job if you have the right tools.
 

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Since this is a double post I'll add that you will need a special sized bolt to remove the flywheel from the crank too.



If you go back into your profile and add where your from and info about your bike it would help everyone here. There may be someone close to you that could help you do the job.
 

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This will be a major job as you will have to change the wiring harness.Fitting a TAI(Transistor Advanced Ignition) engine into a CDI CX is not too bad but the other way round is a big job.I'd look for a Transistor Ignition engine.



just out of interest have you re-built engines before?
 

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Discussion Starter · #7 ·
Yes I have rebuilt many car engines and I just finished an 1983 knighthawk about a month ago. I just have never messed with a cx before sorry if it was a dumb question. I just don't know much about these bikes.
 

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Yes I have rebuilt many car engines and I just finished an 1983 knighthawk about a month ago. I just have never messed with a cx before sorry if it was a dumb question. I just don't know much about these bikes.


Not dumb at all.I'm trying to remember the sequence for swapping parts for the engines and I think I was wrong in my 1st post.



Do you know if your present engine has a manual or automatic Cam tensioner?At the rear of the engine near a 17 mm inspection hole/cover just above there is a 10mm bolt if it's a manual adjuster,



The bolt is number 17 on here but comes out through the rear engine cover,



http://www.cmsnl.com/honda-cx500a-1980england_model16465/partslist/E16.html



It's hidden behind this inspection extension pipe that my CXs have fitted,



 

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Discussion Starter · #11 ·
I picked up the engine from the 1980 today. So I will be removing the aft cover and seeing first hand the differences. I took the wiring harness out of the donor bike also. I will let you guys know how things go. Thanks for all the help any and all is great.
 

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Doesn't an '80 have the old style rear engine cover? That motor has an extra motor mount screw hole cast into the cover. I'd swap in the '82 electrics onto the '80 motor.
 

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If memory serves the carbs on the 82 are slightly larger. Like 1mm... Also there are a pair of triangle shaped engine hanger bracket plates bolted to the frame top tube on earlier CX models but not on an 82.



Well I checked the facto manny and the carbs were 35mm venturi in 78 and both the 80 and 82 are 34mm. I did not find anything else in the addendums between 80 and 82 that would indicate any major issues swapping motors.



The 82 GL went to a Transistorized ignition in 82, this simplified (and changed the stator design) I believe it allowed for more current draw for things like radios and faring accs. the CX stayed with the CDI.



The pics do indicate the hanger brackets on the 80... My 82 does not use them and subsequently has some strange looking plugged holes (look like broken studs) in between the Jugs.
 

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The motor will work, but your going to have to change the stator and flywheel inside the engine as well as the rear cover. Your 82 has a TI ignition and the 80 motor has a CDI ignition. While it's apart you should change the mechanical seal and oils seal, check the timing chain and tensioner too. To do this you will need a rear cover gasket at least.

It's not a hard job if you have the right tools.


I think only the GLmotor (silverwing) went to TI in 82. IF I'm not mistaken, It did simplify the stator design getting rid of the pulser/advancer bits and making it just a generator...
 

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I think only the GLmotor (silverwing) went to TI in 82.


The 82 CX was TI too.



You should be able to use the 80 motor with the flywheel, pickup, stator and rear cover from the 82 engine.

There is a difference in the crankcase venting system too, but it should not be a problem,you may have to cap a couple of holes on the 80 motor.







Edit; I was thinking about this and I am not sure if you need to change the flywheel or not,,you would if you were using an 82 motor with a 80 rear cover, but you are doing the opposite.

Anyone else know if there is a difference in the flywheels other than the little silver plug?
 

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so....just to summarize



1981 GL500

1982 GL500

1982 CX500

1983 GL650

1983 CX650



are all TI ignition
 

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The 82 CX was TI too.



You should be able to use the 80 motor with the flywheel, pickup, stator and rear cover from the 82 engine.

There is a difference in the crankcase venting system too, but it should not be a problem,you may have to cap a couple of holes on the 80 motor.







Edit; I was thinking about this and I am not sure if you need to change the flywheel or not,,you would if you were using an 82 motor with a 80 rear cover, but you are doing the opposite.

Anyone else know if there is a difference in the flywheels other than the little silver plug?
You must change the flywheel and the stators! The flywheel difference is one timing slot verses two and a magnet pickup for the timing on the CX.
 
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