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Discussion Starter · #1 ·
Measured the VAC between the two wires and at idle only had 23.4VAC and at about 5 to 6k had 32.5VAC.



Resistance Values of the Stator Contacts as measured HOT: 20 minutes after riding.

1/5 95-116 124.3

2/5 81-99 108.4

3/5 185-225 233.0

4/5 95-116 122.0

6/5 81-99 107.5

7/5 185-225 234.7

8/9 77-95 96.4

5/9 387-473 491



they all seem to be about 8 Ohms above the max...I think this is ok?



Voltage at the Battery running is 13.85V Cold = 12.85 (same as always)



Other Items to note:

-no vaccum leaks

-spark confirmed on both sides

-fuel to both carbs (carb bowls drained)



Plug Condition after limping home:

Left Golden Brown

Right Wet, Black, Sooty.



Plug Condition prior to riding:

Left: Golden Brown

Right: Golden Brown



Recent Maintenance added some distilled water to battery such that the levels were at the mid points of the High & Low all the way across.



Road the bike last night--it was UNREAL how well it performed--I am guessing Tuned really well.



I know I have spark, maybe I have weak spark...and the bike will run, but just not very well...could it be that the CDI is failing, and my output voltage is not high enough?
 

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Discussion Starter · #3 ·
The bike was running fine all night, stopped off to have a bite to eat, got back on, she ran fine for about 10 or so minutes and then when I went to accelerate, there was none. I had the bike out last night and she ran the best I have ever had her.



When she started acting goofy it is around 1800 rpm, there is little to no accelerations, WOT and she goes when she wants to.



It sounds normal at idle, like you can hear both cylinders, and then you hit that 1800 to 2000 and it sounds like you are on one cylinder. Can't get much past 45 to 50mph, and shes not in a hurry to go anywhere.



As soon as I got home, I checked the cylinder temps just above the intake ports and I was reading 181 to 186 degrees F on both sides which was a bit confusing.



I think the biggest thing I noticed was that it sounds like one cylinder, yet I have spark from both plugs.



I recently did the brass Rod Mod, and I am running resistive plugs...so I know the plug caps are clean.



Original CDI, Coils, Stator...
 

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Failing coil? Recheck boot. Advancing pulsar ok? Assume G-47 original type stator? Do you have a Harbour Freight Tools nearby?
 

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Discussion Starter · #8 ·
Tried the coil swap?


haha...its 130 in the AM here, and I am beat. I am depressed at Marshall's passing, wanted to make the best of riding tonight in honor of him, and well I guess its fitting that I am troubleshooting eh? I know he would have said something already




This is the same Path I went down last time. I will try the coil swap next...this should tell me if its a bad coil or if it is in fact the CDI correct?



Nate, as far as I know the Stator is Stock and Original, as are the coils. I don't know a thing about the Advancing Pulsar or where it is even located. I do have a harbor freight tools 12 minutes away.
 

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I miss lot of stuff on here and

reading this thread gave me the news about Marshall

Very sad indeed.





Rick

the voltages you read had to have been in circuit as you had the engine running

They will be, are bound to be, low when measured in circuit under load

the stated 80-90ACV figures are open circuit, no load, cranking voltages

so dont get side tracked by that

the other figures dont look too alarming
 

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One rough test I used to do on CDI bikes is

to measure the open circuit cranking voltages on the orange

and pink wires from the CDI



open the orange and pink LT wire connectors from the CDI

set a digital meter to read 250V DC

Clamp the black lead to battery neg

Stuff the red orobe up one LT connector maing sure

you get good contact with the metal tube

Crank the motor for a few seconds while watching the display

You wont get a steady reading but I expect to see figures around 150 VDC

on a good running bike.

I've seen as low as 6 VDC on a failed CDI



You should get similar readings on both channels
 

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Set the bike to a high idle speed.Then with an insulated pair of pliers remove one Plug cap in turn.



You should be able to keep the bike running on one cylinder.If you can't then the problem is most likely,"Side Specific"?



If the carbs have been cleaned but no inline filter fitted crud can get through.
 

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Harbour freight has a neat little tool I was tempted to grab, its just a few bucks. It resembles a coil but it has a light inside. On one end it has a spark plug boot and the other it looks like a spark plug. So you put it inline and start up your bike, then you can watch for spark irregularity.



When my cdi failed it acted goofy. Cost me a lot of money in the process since I thought it was fuel related. Not long after, the stator charge coils went out. But that's me not you


I was getting spark!!!!! BUT,,, it was having a problem with timing. Sometimes it would run, sometimes it wouldn't. I've read others accounts of cdi failings, they have reported strange behaviour. Unfortunately, these things can be the worst to properly diagnose. A G-8 stator and an Ignitech cdi makes life on the bike much simpler. There is just less that can go wrong.
 

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Similar thing happened to me yesterday. Went for a ride and the bike wouldn't get above 4500RPM. Limped her home and found that my right side carb was stuck down and wasn't moving anytime soon. So cleaned up the carb got that moving again yet I'm still having the same issue; although it'll get up to 5K before dying out. I'm going to try swapping out the coils now. I'm really hoping it's not the CDI box AGAIN. I just bought a parts bike for $150 just for the CDI box, But it's also nice to have every other part I'll ever need standing by.
 

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Discussion Starter · #16 ·
The behavior of the bike was somewhat similar to the other time I had this issue...maybe some of you remember? the right side is the culprit yet again. I will try swapping the coils, but one thing I really need to do is clean my fuel tank. I do have an inline filter, but I still found silt in the bottom of the baby food jars when I drained them down.



If the piston inside the carbs gets stuck or hung up due to say rust silt, could this cause the same symptoms as I have described? I would think that would cause the carbs to be totally out of sync, one side depending upon where the piston is hung-up, could cause either little to no fuel, or TOO MUCH fuel.



So let's try this for a hypothetical...

Problem Right side Carb Piston Stuck, translates to right side plug is wet and sooty black (rich), still have spark but it is getting too much fuel...sound plausible?
 

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Well in my case the coil wasn't the issue. I've got something wrong going on in my right head. The carb slide isn't stuck but it won't go up when I'm into the throttle. It seems the compression is blowing right through my carb. Must be a bad valve or just misadjusted.



That sounds like a plausible cause Rick. Or it's stuck down and not getting enough air.
 

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Discussion Starter · #18 ·
has anyone ever had a carb piston hang up? What does that cause?
 

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has anyone ever had a carb piston hang up? What does that cause?


I always polish both the pistons and needles in mine when I have the carbs out with Metal polish and check for scores on the pistons.Then test by lifting with the tops back on before re-fitting the carbs.
 

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When my cdi failed it acted goofy.

I was getting spark!!!!! BUT,,, it was having a problem with timing.


Took out my starter clutch when my CDI went. The bike died, but tried to start. As is normal, you suspect many things. As I was cranking she threw a spark at a very bad time, stopped the cranking dead in it's tracks and kicked the engine backwards. I wouldn't trust a 30+ year old CDI as far as I can throw one, when it doesn't up and die at once, it can send you in all kinds of directions which always end at an expensive dead end.
 
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