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Hi people. I need a little help with my CX500. It is overheating towards the red zone and takes ages to come down even when idling. I dont have water in the oil or smoke from the exhaust so i dont think its the head gasket but cant be sure. I thought it was a coolant leak but i cant see one. there is a little oil and water in the air filter box and a smell of fuel. I have recently replaced the head gaskets as they where leaking coolant and replaced the stator because it was shot and flushed the cooling system out then filled it with good coolant mix 50/50. I have replaced the radiator cap for a new one and still the problem. could it be timing, the engine sounds a bit crappy and i did take off the pulsar to clean every thing out when doing the stator and oil seals or is it something else. like something i did wrong. please help.
 

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Today I helped a friend with his cx. His temp gauge did not work. Checked the 7V reg and he had 6.85V--OK, but no voltage at the sender. We replaced the wire and he had a "working" temp gauge, until he went for a ride around the neighborhood and came back on the red line, but the return water pipe was cold. We started to suspect the thermostat, but noted the gauge fluctuated with engine speed. I rechecked and now there was 11.8 volts at the sender.

The regulator was all over the place. I have it gutted ready to install Marshall's "kit".

Anyway, what I'm getting at is check the voltage from the 7V reg. It is the green/blue stripe wire under the tank that connects to the sender, or access it in the headlamp where it comes from the temp gauge along with a yellow wire. Hope that is the problem rather than a t-stat or clogged radiator.
 

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Did the problem show up immediately after the stator change?



It is overheating towards the red zone and takes ages to come down even when idling.
The cooling system on these bike is probably the least efficient at idle. Once it was warm it would take a long time to cool down at idle. It should cool better when moving.



Since you filled it when you put it together have you checked the coolant level in the rad, after running the engine, to make sure there was no air in it and you did get it full?



Where are you at? Somewhere warm?
 

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Did it overheat BEFORE you took took the rear cover off to replace the stator ?? Or did the over heating problem just now start after that ?



Was coolant actually flowing through the system ? You can check this by feeling the coolant pipe on the L/H side of the bike...it should start to get real HOT as and after the bike warms up.



If this over heating problem just now developed after you flushed and re-filled the radiator and wasn't a problem before you did that then it's possible you didn't "burp" the system before you put the cap on the radiator.



So the question is was it over heating before you did all the work or just now afterwards ?



EDIT: I think a couple of us tried to answer you at the same time as we've both asked you a redundant question.
 

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Discussion Starter · #8 ·
I have checked the coolant level and it is full to the top in the radiator. I forgot to mention that i have done a cooling fan mod using a ducati electric fan that i have switched on all the time as the temp switch hasnt yet been fitted. this was to make the cooling system more efficient but it was getting hot before the mod hence why i did it. The engine did start to get hot after the stator change. Woyuld it be the stator again (i hope not) or could it be something i did wrong. i went through the haynes manual to the letter. by the way, i live in the uk so the climate at the moment it moderate. nether warm or cold. The modification to the cooling fan can be found at http://globalcxglvtwins.hostingdelivered.com/viewtopic.php?f=6&t=209

The coolant is flowing well and the thermostat is opening and closing. I did a timing check this morning using a strobe timing gun and the timing marks are bang on.
 

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If you are POSITIVE that the coolant is flowing throughout the system WITHOUT a doubt and the fan is always on then the only thing it could be is that your gauge is bad giving you a FALSE reading hence the 7v regulator is bad.



Make sense....that is IF you're sure that the coolant IS flowing throughout the system FULLY and COMPLETELY without any restrictions such as even a partially clogged radiator.



EDIT: ALTHOUGH since you say this problem only reared it's ugly face AFTER you pulled the engine then reinstalled the radiator it sure makes one (me) think you didn't "burp" it properly which seems to make as much sense as the 7v reg being bad.



BEFORE I did anything else I'd pull that radiator cap off, start the bike, let it warm up and see if that fluid level in the radiator drops down with the cap off as the bike warms up.....IF it does then you just "burped" it.....then top off fully. (I'd at least try this first)
 

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Seems to me the one maybe significant thing here, - that the coolant impellor has to be removed to remove the rear cover



in order to replace the stator.



How were the impellor and camshaft splines?



No pinch off at the lower hose?
 

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Seems to me the one maybe significant thing here, - that the coolant impellor has to be removed to remove the rear cover



in order to replace the stator.



How were the impellor and camshaft splines?



No pinch off at the lower hose?


I was thinking on those lines as well.....but then again I was also thinking "overheating wasn't a problem BEFORE he pulled the rear cover....and it really won't go back together unless it's back together correctly"......right ?
 

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Now here's a scenario I wouldn't wish on anyone, unlikely, but can see how it could possibly happen.



What [hypothetically] if you managed to trap a stator wire or two behind the stator when it was assembled into the rear case. What if this caused a 'skew' in the mounting of the stator causing it to come into mechanical contact with the rotor.



Could this friction generate enough extra heat to cause general overheating?



I'm hoping for the simple and easy,- the pinched rad. hose gets my vote, good luck.
 

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as you have obviously removed and refited the impellor recently

I'd check for coolant flow


I thought about this too, but unless the splines were stripped(as CXPHREAK mentions), wouldn't there be leakage from the weep hole if the impeller was not fitted correctly or loose.



You did refit the thrust washer? And only one thrust washer? I once mistakenly installed two thrust washers and found the engine would not turn, the impeller was hitting the water pump cover.

If you do not have any thrust washer, the impeller would rub on the inside of the case,,, If your splines were worn some, and you did omit or double up the washers, it could possibly strip the splines completely when the engine started,,, unlikely but I suppose it is possible.



I suppose it could also be the 7 volt reg. At idle the stator output would be lower so the gauge may drop down slowly.



I would try idling with no cap until the t-stat opened and visually confirm the coolant is circulating.



You could also try flushing the cooling system,,,, if there is still a problem then remove the w/p cover and see if anything is wrong there.



How long did you have the engine out for the stator repair?

I was thinking if it sat out of the bike for a while, the t-stat could be stuck from sitting.



After re-reading this post, in other words,,it could be anything
 

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I once mistakenly installed two thrust washers and found the engine would not turn, the impeller was hitting the water pump cover.


Really ? wow.....that little plastic impeller locked the engine from turning ? I'd have thought that the engine would still turn and just break the impeller into pieces.



EDIT: Allan, I was just thinking you probably found out it wouldn't turn by cranking the engine by hand right ? I bet if you actually started the bike that it might have turned and tore up the impeller. Am I correct ?
 

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Have you checked the voltage from the 7V reg yet? It is the simplest test and could avoid a lot of more difficult tasks if it is the culprit. In this situation a cheap hand held infrared temp sensor from Harbor Freight is indispensable for verifying temperatures at various places in the cooling system.
 

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Really ? wow.....that little plastic impeller locked the engine from turning ? I'd have thought that the engine would still turn and just break the impeller into pieces.



EDIT: Allan, I was just thinking you probably found out it wouldn't turn by cranking the engine by hand right ? I bet if you actually started the bike that it might have turned and tore up the impeller. Am I correct ?
Rick, I searched the old forum and found the thread,,I was Harold on the old forum,,this was my very first post.



http://choppercharles.com/cs/forums/7186/ShowPost.aspx
 

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An afterthought. If the stator was replaced due to not charging, the increased output of the new stator could be just more than the failing 7V reg could handle?


That's a possibility. Good thinking. I wondered why the 7V. reg would fail after the stator change,,but you may be right about that,,it makes sense to me.
 
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