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'84 CX650E that is evolving into a GL500
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The people that say you should replace the mechanical seal every chance either A) don't have much experience with these engines and think the seal is too fragile to survive disassembly (I once took an engine abart 6 or 7 times without replacing it with no problems) or B) Don't know that forum member Shep developed a method of replacing the seal with the engine in the frame (at least 10 years ago, probably more).

When you look for the spark plug caps make sure you include the bike's model number in the search terms.
 

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1978 honda cx500
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Discussion Starter · #202 ·
The people that say you should replace the mechanical seal every chance either A) don't have much experience with these engines and think the seal is too fragile to survive disassembly (I once took an engine abart 6 or 7 times without replacing it with no problems) or B) Don't know that forum member Shep developed a method of replacing the seal with the engine in the frame (at least 10 years ago, probably more).

When you look for the spark plug caps make sure you include the bike's model number in the search terms.
Ahh ok perfect, so i shouldnt have to worry about it. And im guessing ill have to buy the spark plug boots seperatly, unless im able to reuse my boots and just replace the caps on the inside?
 

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'84 CX650E that is evolving into a GL500
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I cleaned and used the original spark plug caps on my CX. I disassembled them, cleaned the ends of the resistors with electrical contact cleaner (NOT WD-40) and Scotchbrite and checked that the resistance was in spec, then cleaned the rest of the parts with contact cleaner & Scotchbrite. For the contact down inside the hole where the resistor goes I tear a small piece off of a Scotchbrite pad, push it in with a small screwdriver, spray in more contact cleaner and push the pad in firmly with the screwdriver while turning it to scrub the inside of the hole, then fish out the pad with a bent wire. When everything is clean & shiny re-assemble the cap and check the resistance to make sure the cap itself is OK (the conductor inside them can sometimes fail).
Make sure the rubber boots at each end of the cap are in good condition and seal well around the wire and the spark plug (if they don't the engine can stall when it rains).
 

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1978 honda cx500
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Discussion Starter · #204 ·
I cleaned and used the original spark plug caps on my CX. I disassembled them, cleaned the ends of the resistors with electrical contact cleaner (NOT WD-40) and Scotchbrite and checked that the resistance was in spec, then cleaned the rest of the parts with contact cleaner & Scotchbrite. For the contact down inside the hole where the resistor goes I tear a small piece off of a Scotchbrite pad, push it in with a small screwdriver, spray in more contact cleaner and push the pad in firmly with the screwdriver while turning it to scrub the inside of the hole, then fish out the pad with a bent wire. When everything is clean & shiny re-assemble the cap and check the resistance to make sure the cap itself is OK (the conductor inside them can sometimes fail).
Make sure the rubber boots at each end of the cap are in good condition and seal well around the wire and the spark plug (if they don't the engine can stall when it rains).
Ok perfect, am i able to buy just the resistors that go inside them? Mine are very corroded through so some new ones may be a better idea. The caps i can easily clean though so thats perfect. So i should be able to just buy the ignition coil and replace the boot on it with mine
 

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1978 honda cx500
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Discussion Starter · #205 ·
In regards to the stator, mine is still working, but ive seen the g8 ones range from 35-100 bucks. Is the stator something that dies often? Would it make sense for me to attempt that replacement as well or just wait for mine to die?

Sorry for all these questions, im a nervous first timer here so I wanna make sure everything is done right.
 

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Remember that the more that you open the engine the greater the expense. If I were you I would not remove the rear cover, just the timing cover so that you can install the Rae-San. The only reason for removing the rear cover is if you want to replace the stator and/or to fit new timing chain and guides.
 

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Discussion Starter · #207 ·
Remember that the more that you open the engine the greater the expense. If I were you I would not remove the rear cover, just the timing cover so that you can install the Rae-San. The only reason for removing the rear cover is if you want to replace the stator and/or to fit new timing chain and guides.

Thats a good point, i thought it would be convenient to do everything at once, but im getting ahead of myself. No need to "fix" something that isnt broken.

Ill just focus on the rae san unit and maybe ignition coils since they are cheap enough. Im going to see if i can clean the boots i already have. In the coild for these bikes, is a resistor necessary? Ive heard of people running without them but upgrading their spark plugs
 

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'84 CX650E that is evolving into a GL500
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I've never seen the resistors sold separately. If yours are too badly corroded to clean you could replace them with pieces of brass or copper but if you do that make sure you use resistor spark plugs (this is a change, not an upgrade).

All CX500 models except the CX500E and the '82 CX500C came with Capacitor Discharge Ignition (CDI), which is powered or triggered by special windings on the alternator's stator. Those special windings that are more prone to failure than the part of the stator that produces power to run the electrical system and charge the battery.
Rae-San ignitions get their power from the electrical/charging system and the one you are looking at is triggered by a hall effect setup so as long as the charging part of the stator is working you won't need to replace the stator.

Because of the room taken up by those special windings there is only room for enough charging system windings to produce 150W. The stators used in later models with Transistor amplifier Ignition (TI) have the same footprint but since the whole stator can be windings that produce power they are rated at 252W output.
It is pretty common for people who have changed to an ignition system that doesn't need the special windings to upgrade to the later stator the next time they have the engine apart for something else.

The pit bike coil you posted looks like it should work but I don't have a CDI bike so I'm not 100% sure. Hopefully someone who knows for sure will let you know.
 

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1978 CX500 "The Grub", 1983 GL650I "Nimbus"
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When you say "spark plug boots", do you mean the rubber skirt that fits around the spark plug cap to cover the plug well? To my knowledge, they are not included with the aftermarket caps, so you'll want to reuse them.
 

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1978 honda cx500
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Discussion Starter · #211 ·
When you say "spark plug boots", do you mean the rubber skirt that fits around the spark plug cap to cover the plug well? To my knowledge, they are not included with the aftermarket caps, so you'll want to reuse them.
Yes those, and when i say resistors i mean these two things im going to add a picture of. One is corroded, and the other looks a little bad too. I also will add a pictire of every component in each of the boots.
 

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I think they're a standard resistor, if anyone knows the spec.
 

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1978 CX500 "The Grub", 1983 GL650I "Nimbus"
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CXPhreak might have mentioned replacing them, but I could be mistaken.
 

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The coil listing shown are suitable. While the plug caps supplied with them are unsuitable for this application I've robbed 5000 ohm resisters from them for use in CX plug caps. They are physically smaller but the spring compensates for this but were the correct resistance. I can't comment on their longevity.

There is also the option of the brass rod mod and running DR8EA resister plugs. Irridium DR8EIX are also an option but pricy.
 

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Discussion Starter · #217 ·
The coil listing shown are suitable. While the plug caps supplied with them are unsuitable for this application I've robbed 5000 ohm resisters from them for use in CX plug caps. They are physically smaller but the spring compensates for this but were the correct resistance. I can't comment on their longevity.

There is also the option of the brass rod mod and running DR8EA resister plugs. Irridium DR8EIX are also an option but pricy.

Ok good to know, i wasnt sure if that resistor was common in other plugs.

Im going to attempt cleaning these. However one of the plug boots has the spring and metal rod stuck inside of it. Seems to be corroded through. So ill see what i can do in removing it.
 

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The spring can often be pulled out with a sheet metal screw depending on whether the spring or resister are in first. This often stretches the spring but I've pulled replacements from biros and disposable lighters.

Partway down this page


new resister caps are listed. This is Silvers UK page but you have Silvers in the US.

Shown are an OEM and an aftermarket plug cap. OEM has 5000 ohm resister, aftermarket no resister. Aftermarket can be run with a resister plug.
 

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