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Discussion Starter · #1 ·
Hi,

Just got a decent shaped CX500c in Lucas County Ohio 3 weeks ago. The bike ran well while test driving. In the last 2 days while ridding for the first time after buying, after few minutes after driving the accelerator and the gear lost power gradually and failed to start at all, then after 4-5 minutes it started again and ran on the road for few miles and felt that it's loosing its power again, managed to slowed down in front of my house and while I was trying to move it to the driveway it failed to rev and move forward on the first gear and dropped power on the bike and the engine stopped. The same thing happenned today while I went to a friends place, it ran perfectly on the road, but while trying to move the bike from the road to the diveway of his house, the accelerator gradually dropped with little rev then same as yesterday. Dont know whats wrong with it, cant rely on it while going outside.

Sometimes few drops of oil (greenish) can be seen under the engine but I think its not engine oil? So every time I go and start the bike its starts fine with the Choke on, idles fine after few minutes.

The bike was sitting in a garage in the winter in PO's place and it was well kept. What should I look at here?

Check if the gas in the tank has dirt or rust in it by draining it? or change the gas filter or air filter?
Is it something because of its too cold here?
I found the right side of the engine head and the exhaust was really cold compared to the left ones. There were sparks on the socket while I removed the spark cap while the engine was running (just to check), after it stopped working, so should I change the spark plug on the right side?
Do I need to clean the carburetor?

I am really new to this type of bike, but can manage tools and love to work on stuff.....so any suggestions are more than welcome :)

Found this forum while digging around the problem. It feels really great :cool: to see a dedicated forum only for Honda CX series motorcycles. :D :)

Thank you.
 

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If I read this correctly, the right head and exhaust was cold while the left was warm. I'm not sure which spark cap you removed, if it was the left one and that caused the engine to stop would indicate the engine is only running on one cylinder. Or was the right plug cap that you removed?

One thing you should do is to visit the Wiki, link in my signature line, and download a copy of the factory service manual for your bike. You might also browse around the motofaction web site https://motofaction.org/motorcycles/honda-cx-gl/

Also have a look at this thread https://cx500forum.com/forum/general-discussion/31323-forum-settings-everyone-should-make.html

Welcome to the forum.
 
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The only greenish liquid that I can think of is the radiator fluid. Check inside your crankcase through the dipstick. Do you see foam? If there is foam in there and you see green fluid on the ground it likely means you have radiator fluid infiltrating your engine block. A second indicator is that it runs better when cold then dies when hot. The engine expands when hot which allows more radiator fluid inside the combustion chamber. This is only a possibility...not necessarily the real issue so check that all out before getting too worried. Good luck. Keep us posted.
 

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On a bike which has sat for an extended period it is not unusual for the mechanical seal to leak. Coolant may be coming out of the weep hole.
 

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Discussion Starter · #5 · (Edited)
Thank you reclinedrelic

If I read this correctly, the right head and exhaust was cold while the left was warm. I'm not sure which spark cap you removed, if it was the left one and that caused the engine to stop would indicate the engine is only running on one cylinder. Or was the right plug cap that you removed?

One thing you should do is to visit the Wiki, link in my signature line, and download a copy of the factory service manual for your bike. You might also browse around the motofaction web site https://motofaction.org/motorcycles/honda-cx-gl/

Also have a look at this thread https://cx500forum.com/forum/general-discussion/31323-forum-settings-everyone-should-make.html

Welcome to the forum.
Thank you very much for your reply.

I am definitely checking all the links that you've suggested. I downloaded manuals from your links :)

I have checked the spark on the cold side so I guess the CDI works...but don't know if the spark plug works or not on the cold side(right one).
 

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Discussion Starter · #8 ·
Greenish oil drop after a quick ride on the bike

The only greenish liquid that I can think of is the radiator fluid. Check inside your crankcase through the dipstick. Do you see foam? If there is foam in there and you see green fluid on the ground it likely means you have radiator fluid infiltrating your engine block. A second indicator is that it runs better when cold then dies when hot. The engine expands when hot which allows more radiator fluid inside the combustion chamber. This is only a possibility...not necessarily the real issue so check that all out before getting too worried. Good luck. Keep us posted.
I have checked the crankcase through the dipstick, there is no foam in there. Don't know what to do next? I'll try and open up the radiator to see if the fan is alright or not? One thing I've noticed that the spark plugs sparks while crankign but they are really dirty or dark...I think I'll definitely change them and then see if the bike starts and run for a long time or not!

Thank you for your suggestion. :D
 

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Discussion Starter · #9 ·
Swap the plugs side to side. see if the cold side follows.
First I tried to start the bike with the choke on...it started for a while then turned off again. Then I switched the plugs and it's still not starting at all. I think I'll change the spark plugs; they are really dirty.
What do you think?

Here are the images of the spark plugs...
https://photos.app.goo.gl/bYevn1QbhUBZNeJX7

Thank you...I'll keep you posted about what happens..
 

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Discussion Starter · #10 ·
here is a great write up be dave on the ti ignition trouble shooting

Ignition Problems
Hey murrayf

Thank you very much for the Trouble Shooting link. My bike starts fine most of the time :) but after running it for a couple of minutes it the throttle fails to rev and give pushing power, even on the 1st gear and then stops. After that it cranks but wont start. After 4-5 minutes later it starts again and then runs for a little while. Sometimes it runs really good unless I stop for a moment and then it does not give me any power on the throttle and gradually dicreases the rev and stops, then another wait. By any chance could it be dirty spark plugs?

Ahsan
 

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those spark plugs are extremely healthy-looking. you will want to check the gaps though............
I don't agree, but maybe that's me. While they each in their own right might look serviceable, as a pairing they show an uneven burn. Poor tuning or balancing of carbs, such as lean or rich. They tell a story, and it's worth a new set of plugs to be able to isolate what the true story/engine status is.
 

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Discussion Starter · #15 ·
!...Problem Solved...!

Thank you, everyone, for the help and suggestions. Changing the spark plug helped...starts faster too and without the choke. :)
The right side of the engine is also running. But didn't see the temp gauge move from the cold spot...but I guess it not that a big deal.
 

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How long did you run the bike, long enough to get the engine hot? Having a working temperature gauge on these bikes is important.
 

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Check that the gauge is actually plugged in. Follow the wire into the headlight shell and see if it's connected. I had the same issue with mine, bought a new sending unit immediately thinking that was the issue, but as it turns out the darn thing wasn't connected in the headlight shell. doh!

!...Problem Solved...!

Thank you, everyone, for the help and suggestions. Changing the spark plug helped...starts faster too and without the choke. :)
The right side of the engine is also running. But didn't see the temp gauge move from the cold spot...but I guess it not that a big deal.
 

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Discussion Starter · #18 ·
Temperature gauge not working or the pointer is not moving at all....

How long did you run the bike, long enough to get the engine hot? Having a working temperature gauge on these bikes is important.
I ran the bike around 20 min on the road, but the gauge didn't move at all. I think I'll follow what @boyracernj said and see actually if the gauge is connected to the headlight or not today! Dont know which wire is what but I'll try. :)
 

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Discussion Starter · #19 ·
Check that the gauge is actually plugged in. Follow the wire into the headlight shell and see if it's connected. I had the same issue with mine, bought a new sending unit immediately thinking that was the issue, but as it turns out the darn thing wasn't connected in the headlight shell. doh!
Don't know which wire is for the temp meter. would you kindly tell me which wire in the headlight shell is for temp. I opened the headlight shell but didn't understand which one to look for! . I ran the bike around 100+ miles at a stretch...it was fine, but the temp gauge didn't work at all.
 

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Don't know which wire is for the temp meter. would you kindly tell me which wire in the headlight shell is for temp. I opened the headlight shell but didn't understand which one to look for! . I ran the bike around 100+ miles at a stretch...it was fine, but the temp gauge didn't work at all.
The 7v regulator has three wires. It looks like the pictures in the first post here: https://cx500forum.com/forum/selling-buying-forum/31874-new-7-volt-regulators.html
Do you have a FSM for your bike? If not see my sig line for a free copy. Please add your bike info to your sig line. it helps others help you.
 
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