Hi every-one,
New CX owner here from Latvia.
First of all sorry for my english(it's not my native) therefore I will try to name all the terms and specifications correctly for your understanding.
So with no small talk here is the problem:
When I give my bike a full throttle it starts to cough. But when I give it a lean throttle it goes all the way to the red-line with no problem.
So for now I can't figure out what could be the problem? Some say that vacuum in carb is bad, some say that I need to adjust more fuel in carb. Previous owner said that he has adjusted everything in carb, even changed it to new one to prevent the problem but still no luck. He thinks that problem could be in valve adjustment. I have checked both spark plugs and wires, filters, cushions..all are new.
I also searched the forum and net, but couldn't find what could be the problem.
I made a short video for better understnding:
As you see at first attempt I give the bike a nice lean throttle(probably halfway or even one third) and it goes up with no problem. Second and third time I give it a full throttle and as you can see it starts to cough at 3000rpm and 5000rpm.
Also I want to mention that when I am riding it in 4th and 5th drive, even with lean throttle the bike starts to cough between 5000-7000rpm and to get it up I have to let go the throttle and gently pull it again to catch back the power and get more rpm.
So I hope that you could help me with this problem couse basically this is the only problem I have with this bike.
Cheers to all cx500 owners
The 5/9 figure is low, even for the alternative figure some bikes have for that one [315 - 385] but this may be a moot point if the stator is an aftermarket replacement. An electrex brand from David Silvers has a 500 ohm measurement for this though. Any idea of the stators source?
3000 RPM sounds a little low speed for a stator fault to manifest itself but it can't be ruled out.
I would also try a new set of sparkplugs even though the current ones appear new. Have you physically checked the resister caps? They should be 5000 ohms if fitted with resisters, 0 ohms if not. Also, what sparkplugs is the bike running? You don't want resister plugs with resisters in the caps.
Don't know exactly but probably some after market from ebay, couse the previous owner said that it wasn't expensive. But as I remember he mentioned that the problem still persisted before the stator change..
The caps look like new and are with resisters. I am going to check later the spark plugs if they are or aren't with resister, couse right now I don't have the right instrument to remove them.
So the bad thing is that I have somewhere lost my plug wrench and any other 18mm doesn't fit in. So for a while I won't be able to tell the plug number.
But anyhow, if you presume that the plugs aren't the right ones do you think just replacing them would fix this problem? Or is there any other things I could check?
And what about adjusting the valve clearance? Could that fix the problem? Couse the previous owner said that he has done everything he could think of to fix this problem but he hasn't checked the valve adjustment, but he said that now they are adjusted to factory standard, and that some other cx owners suggest to do some adjustment to the valve clearance..
Do you have access to a timing light? One you clamp onto the spark plug wires? If so, hook one up and go through your running test as you showed us in your video. Do both plug wires, one at a time of course. Look at the light as you run it. Is the light going out when it starts to hesitate and not accelerate? If yes, you have trouble with the ignition system. If no, you have fuel/air problems.
Thanks for advice. As soon as I get my hands on one of these I will tell the results it shows.
I just got a set of valve clearance meters, so gonna try to do some adjustment and see if that has any effect to this problem. As I read on the forum the original clearance suppose to be 003 and 004, but as I understand that is in inches..could someone specify that in mm, couse my tool is in mm. Maybe some advice how to do it correctly and what adjustments I should try?
So I did a little research on this forum and found this thread: http://cx500forum.com/forum/technical-help-forum/9084-cx500-unknown-problem-help.html
Found some similarities that my bike also has. And I have come to the conclusion that there is some problem with the stator and I need to install Ignitech. Today while riding my bike I strengthened my thought that the stator is failing in high rpm(based on what I have read). Previously riding my bike I could easily rev it with half throttle to redline, but now it can't go over 5-6rpm with third or fourth of throttle in any gear.
So could installing Ignitech fix this problem? Couse it is not very cheap to buy one, and here in Latvia I doubt that I will find any person who has it to put in my bike for test reasons. And I really don't want to spend 200eu just to put a new unit in and see that it doesn't fix my bikes problem..
Really hoping for some advice from you guys..
Also wan't to mention that today I adjusted mixture screw to test if something changes but still no effect - only that on leaner mixture now my bike is holding better rpm on idle ;D
I was starting to strip my bike down, and now I have a better view to my carbs. As I was looking at them I noticed these two little "tubes" :
So I was curious what are they? What do they do? And my main question is do they need to be connected? Couse they are placed directly opposite to each other like they are meant to be connected..
My carb number is this:
Maybe you can give me some info about these carbs..
Thanks murrayf for your answer. My thought was also that they are some kind of vents, I just needed to make sure I was right, couse my grandpa suggested that maybe they need to be connected.
Are there any manual or blueprint or crosscut of these carbs, so that I won't be needing to ask question like that and see how those carbs work?? ;D
Yup, the answer is always carburetors on these bikes, you could eliminate the problem by purchasing a set of Murray's Mikunis, they are most excellent.
Ahaa, thanks for the info guys.
I have already ordered the Ignitech unit, so lets wait and see how the bike handles it.
And the Murray's carbs are also on my purchase list, but I wont miss out a chance to take off my carbs and try to clean them.
Oh and btw - could there be a possibility that there is some problem with the vacuum in the carbs?
Vacuum is the flipside of compression, so if your compression is good your vacuum will be.
The caveat here though is vacuum leaks. First chance for one comes where the manifold joins to the head if the O ring has failed. Next on the hit parade is the carbs fitment into the manifolds rubber boot and cracks in the boot itself. Ditto the airbox side joints and boots including the boots attachment to the airbox.
Another source of leaks are around the throttle and choke shafts. These carbs don't appear to wear much on the throttle shafts but the choke shafts do wear some, especially the right but leaks here are usually fairly negligible.
Leaks at the vacuum cap are possible, but I've not seen it.
These can all be checked with an unlit butane torch or similar while the engine is idling, looking for variations in RPM.
Just instaled Ignitech, had a first test run, full throttle and bikes goes like a charm. No bogging, no spitting..looks like Ignitech done the trick and is the solution.
But anyways thanks for all the help and info - thanks to you now I have a greater knowladge about my bike
Hope I won't be needing to come back here again But if so I surely will
Wait one dang minute.....this forum goes well beyond the technical side....no reason you can't hang around and stay in the loop with everyone, regardless if your ride is on target now. Glad you got it sorted out!
I probably have the same problem ....
also my value 9-5 is a little low ...
and to me, the motor stops in 5/6000 rpm ...
I'm going to see for the ignitech
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