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Discussion Starter · #1 ·
Been chasing a stubborn starting issue for the last year which seemed to clear up after rebuilding the carbs on my '80 CX500C for a few weeks. It seems that when I would start it every day or two she would run fine. But if the bike sat for more than a couple of days, it was nearly impossible to start it. Spayed some carb cleaner into the carb 3 weeks ago and she fired up (after alot of cranking) and she ran fine. In the middle of troubleshooting a found that the spark plug boots had major issues internally (in other words not an issue with the resister/etc). Just got the new boots in and immediately swapped out the resisters with a brass rod. Trimmed down the plug wire to make sure everything was connecting.



Good so far. Now remember it has been 3 weeks since she has run. At this point the bike is refusing to even try to fire. I have rechecked everything with the spark plug but all looks good. I tried removing the plugs and left them out to check for spark and there is none. The starter is cranking fine so I know the ignition switch, and starter button are fine. Below is everything I have checked so far,



-Verified the kill switch was fine.

-Tested resistance at the connectors by the CDI which and everything was within specs EXCEPT the Low Speed source coil reading which was 334 ohms (norm range should be 387-473).

-verified the 3 yellow wires are not shorted to ground, they are all fine.

- tested the voltage when cranking for the low and high coils, Blue = 72vac and White = 61 vac (I had tested these two 3 weeks ago and they were slightly higher then, (Blue=84vac, White=68vac)



So to me it looks like my Stator is beginning to head south. would that create my hard to start issue? Also, is there anything else I can test out to verify any other issues? Since the CDI's have so many issues, plus I am not really comfortable pulling the engine I would probably go ahead and get the Ignitech unit to deal with the issue unless anybody has any other options for me.
 

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Weak/tired/crap battery?

Next time you leave it for a few days, try a booster cable from a car/truck

if it fires up like a good un this would suggest its that

I had a new battery that was a PITA.

when my son sold his CX I swapped my old battery he'd been using for my 'new' one

and it starts on the button now even after a few days lay up.



It took me a while to figure it out as I wrongly assumed that as the battery

was much newer than my old one that it couldnt be that.

Damn well was though..
 

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Discussion Starter · #3 ·
Weak/tired/crap battery?

Next time you leave it for a few days, try a booster cable from a car/truck

if it fires up like a good un this would suggest its that

I had a new battery that was a PITA.

when my son sold his CX I swapped my old battery he'd been using for my 'new' one

and it starts on the button now even after a few days lay up.



It took me a while to figure it out as I wrongly assumed that as the battery

was much newer than my old one that it couldnt be that.

Damn well was though..


Put a new battery in it about 2 months ago, just after rebuilding the carbs. It's getting a little weak as of tonight from constantly trying to get it to fire, so I put the trickle charger on it to get it back where it should be.I agree, when I put the new battery in it made a huge difference in start up times.
 

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Was it converted to a vacuum fuel shut off??? If so the carbs dry up in that much time and you have to crank for a bit to refill the carbs.



Also, if converted to a vacuum system, there may be a leak in the vacuum hose.
 

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Discussion Starter · #6 ·
Was it converted to a vacuum fuel shut off??? If so the carbs dry up in that much time and you have to crank for a bit to refill the carbs.



Also, if converted to a vacuum system, there may be a leak in the vacuum hose.


No it does not have the vacuum petcock. Have already checked that fuel is flowing fine out of it.



Though I realize I could have a "new" fuel issue, I am pretty sure not seeing "any" spark at the plugs with them pulled is my main issue. I do plan on replacing the fuel in my tank (10% ethanol type) with non-ethanol later this week once I get my bigger gas can from down in NC (so I have someplace to drain it into) to prevent any issues from that as discussed in other posts recently.
 

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ok how are you checking spark with your plugs??? are you placing them on the valve cover and if so thats a bad spot to check at what i do is i take them out (unscrew them) and place them in the plug caps and leave them in the spark plug hole that way you can see the spark and it also lets you hear it to i hold the lead with one hand and hit the starter button with the other it seems to work for me
 

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Discussion Starter · #8 ·
OK, sometimes a curse word would seem SO appropriate, but since I am not supposed to do that anymore (being a preacher and all), I'll just beat my head against this concrete way for awhile.



Thanks "Lucky" for making me rethink my spark test. Helps to have it NEAR something for the spark to go to. DUH!!!



OK, latest. after charging the battery overnight (and checking the spark CORRECTLY) I have good spark. Rechecked my voltages on the Blue/White wires, Blue NOW reads 106 vac and the white reads 85vac. So apparently, having a very good charge on the battery makes a HUGE difference in the readings. resistance readings still show low for the low speed coil though, about 335ohms.



I was able to get it to burp a couple of times, but since the bike is in the basement, and my wife gets real unhappy if I run it while it is down there, will have to wait until tomorrow to try to get it to fire. Still have to dump the fuel in the tank and replace it with the non-ethanol I have first. Plus I plan to use a can of Sea-Foam as well.



**Question for all** Could the low resistance reading on the low speed coil be the cause of the hard to start issue?
 

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i would think that the low speed would be a very good reason for it not wanting to run but i could be wrong if i remember correct the low speed windings on the stator control the starting and idle up until 5k on the tach and then the high speed windings kick in that is if i am right but i could be very wrong here so dont quote me on it



and i am glad i was able to "show" you the way to check spark
 

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I doubt the low resistance you noted is related to the problem. If you are showing a good spark on both cylinders with the plugs out, you probably don't have an electrical problem. That just leaves compression, timing, and fuel. It is so rare to find an engine that is worn out enough to not have at least a 100 lbs of compression. The timing is essentially fixed, and non adjustable. That just leaves the fuel. Get a can of starting fluid and shoot a burst into the air cleaner opening. About a half second worth should do it. Then try to immediately start the bike. I'm guessing that it will fire up and maybe run for a second or two. Maybe even keep running.



If that happens, guess what is next. Yep, carb time again. A lot of guys report that it takes two or three cleanings to get them right. Or one deep, complete, ultrasonic, Larry's way cleaning.
 

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but blue if the low speed windings are going out on his stator wouldnt that make it a pain to start?? at least thats what i was gathering from what i have read on the old forums please enlighten me here



i forgot to mention the starting fluid also.......make sure it is starting fluid not nothing else (the starting fluid is the best to use at starting an engine) i have had people tell me to use carb cleaner that it works bettere than SF but no it doesnt
 

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Yeh, Lucky, that would cause hard starting. But he says he has 85 VAC on the white wire. That indicates that the low speed winding is doing it's thing. It may be a couple of volts low, but not enough to cause a problem. What is the old saying? "******, ninety, bluie higher". And he said that he was getting a good spark while cranking. This would be the low speed winding providing that spark. I suppose there is a possibility of the CDI messing up internally, but again, if he has a good spark, it is also working correctly.



I have seen sparkplugs not fire under compression, but fire outside the cylinder. That is why one of the first things to try is replacing the plugs. For $4.00, you can eliminate that possibility.
 

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ok well i didnt know that the low speed windings controlled the spark......thank you for letting me know blue and i am sorry for sounding like an idiot
 

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Hey now, the only idiots are the ones who think they already know everything and the ones who never ask questions.



And it sounds to me that if you're getting a good strong spark while cranking the starter then your problem is fuel or air. After cranking for a bit are your plugs wet and gassy?



I'm certainly not too proud to admit that I had the carbs out and apart at least 6 times before I was happy enough with them to take my big ride. Seems that spotless just ain't good enough for these carbs...
 

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Discussion Starter · #15 ·
Thanks for all the advice. As for the spark, it's sparking, but how strong it is is probably subjective to every-bodies viewpoint, and since I haven't ever seen a know good strong spark I am hesitant to say it is strong, but it does spark.



I did clean the carbs using Larry's method with an ultrasonic cleaner, but have recently been concerned about them due to the ethanol issue, seem to have had several issues with carbs on the mower, weed eater, this past summer that I never had before, hence why I am thinking the Ethanol might be a culprit.



The plugs are wet/gassy after trying to start so I know the gas is getting to them. The issue I am looking at is what seems to be the beginnings of some sort of failure. That is why I am leaning toward the low stator resistance reading.



I will try to get it started tomorrow after swapping out the gas in it. How hard it is starting will give me some more feedback an where to go next with it.
 

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Lucky, I hope I didn't imply that anyone was an idiot. Like Sam said, the only ignorant are those who do not ask questions. Life is a learning process, I have just been in the process longer than you.
 

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Double post. Sorry
 

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Lucky, I hope I didn't imply that anyone was an idiot. Like Sam said, the only ignorant are those who do not ask questions. Life is a learning process, I have just been in the process longer than you.




oh no you didnt blue i made my self feel like an idiot that is all i should of realised that the low speed on the stator would control the spark it only makes sense.....so yea that is why i felt like an idiot......
 

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Since Ethanol has been brought up again, would Seafoam have a positive effect against the negatives noted about Ethanol?



Joel in the Couve
 

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Discussion Starter · #20 ·
Well, I drained all the gas from the float bowls and the tank, then filled it with non-ethanol type gas. Took her outside and she fired up on the first try with hardly any cranking at all. Took it out for a quick ride (ie very cold one I might add) and noticed she is idling a bit high and she tens to bog down at higher speeds (above 70). Bot used to be fine just 4 weeks ago when she ran last. I am thinking either the spark plug boot mod (installing brass rods) or more likely the ethanol has clogged up the jets somewhat. I will be starting a new post showing a photo of what the ethanol gas looked like between the float bowls and the tank, (it amazed me), I'll label it "Ethanol Issues" and put it in the General section in a few minutes.



Bottom line here, 1) Spark plug boots were definitely bad (replaced). 2)A minimal drop in the battery required a recharging to max it out (I thin my stator on the low side is starting to go which means it needs full battery power to fire). 3)Replaced the gas with non-ethanol type.



All the above appears to have exhibited the non-starting, hard to start scenario. Will probably go ahead and redo the carbs this winter just to make sure they are happy before the spring.
 
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