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Discussion Starter · #1 ·
Recently, as the weather here has turned from a sizzling 95plus and humid/rainy (day) and low 80's at night to now mid 80's days at best and dry/sunny with low 60's overnight, I have noticed a decrease in mileage accompanied by richer running carb mixture (darker plugs).



Can the 20degree lower change in temp and lower humidity cause the mixture to need adjustment?



A further possibility is that my battery has recently run dry twice in the past six month (5 of the 6 cells but it still started) . It was refilled and charged, starts the bike fine etc. Does the somewhat weakened state of the battery severely effect the running of the bike, and,



Particularly at night, the engine does not seem to get very hot. Even after a long pretty fast run I can keep my hand on the cylinder heads for quite a long time without discomfort. Back during the hot days I measured the temp with a laser temp gauge at various point on the cylinder head and it read a consistent 170-175 degrees after a good run.



Your advise and suggestions are appreciated,



Mark in Thailand
 

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Are you operating with the thermostat removed? If so, reinstall it. Maybe the t'stat is not closing as it should (acting as if it were not there). Test this by starting the engine cold and placing your hand on the chrome water pipe. It should remain cool for awhile until it suddenly gets much hotter, as the t'stat opens. If it slowly and gradually gets hotter as the engine warms up, it's stuck open. A cold running engine can give the symptoms you describe.
 

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Discussion Starter · #3 ·
Are you operating with the thermostat removed? If so, reinstall it. Maybe the t'stat is not closing as it should (acting as if it were not there). Test this by starting the engine cold and placing your hand on the chrome water pipe. It should remail cool for awhile until it suddenly gets much hotter, as the t'stat opens. If it slowly and gradually gets hotter as the engine warms up, it's stuck open. A cold running engine can give the symptoms you describe.


I'll look into that tomorrow. Feels like it might be stuck open.



Thanks for the response.



Mark
 

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Are you operating with the thermostat removed? If so, reinstall it. Maybe the t'stat is not closing as it should (acting as if it were not there). Test this by starting the engine cold and placing your hand on the chrome water pipe. It should remail cool for awhile until it suddenly gets much hotter, as the t'stat opens. If it slowly and gradually gets hotter as the engine warms up, it's stuck open. A cold running engine can give the symptoms you describe.
Rich,i as well as mark get a summer/winter difference...in as much as,without any adjustment.idle revs in summer 1100rpm...this jumps to 1400 rpm in the winter.its very noticable.
 

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Okay, Bandit, rub it in. Just how cold does it get there in the winter?
 

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Okay, Bandit, rub it in. Just how cold does it get there in the winter?
Rich,no honestly,this is the truth.its happening.if mark had not posted this i would not have posted.its not a real problem,just odd

winter......about 14c at a riding lowest

summer......region of 36c to 50c

its as if the air temperature makes a difference.

sorry mark,its not a highjack,i just thought it was relevant
 

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Oh good it's not just me.



Yeah about 300 rpm.

I don't know where it starts but my bike really likes it under 60 degrees american.
 

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Discussion Starter · #8 ·
Rich,no honestly,this is the truth.its happening.if mark had not posted this i would not have posted.its not a real problem,just odd

winter......about 14c at a riding lowest

summer......region of 36c to 50c

its as if the air temperature makes a difference.

sorry mark,its not a highjack,i just thought it was relevant


Bandit,



Hijack? Not at all, it's good to know others experience the same.



I did check out the thermostat and.....it just ain't there! Went to the parts bin and I have a replacement, checks out good but, no gasket. Can/should I use a silicone gasket maker instead without detriment?



My temperature extremes are just inside yours, with summer nearing 45 with medium to high humidity and winter lows near to 18 with very low humidity (tho tonight there is a bit of rare January rain). As air density does change with temp and humidity, I suppose the denser air of cool and humid conditions might just be optimal. Performance track racers adjust to it almost by the hour and aircraft are also aerodynamically effected by changes in altitude and temperature (air density). Modern electronics and fuel injection systems probably adjust automatically within ranges. Naturally aspirated, carb engines like ours do not.



I'll get that thermostat in and see what amount of difference that makes. The fuel economy drop seems excessive, much more that last year. Maybe though I am just more sensitive as gas prices have risen dramatically to almost 1.38USD per liter for true 91 octane fuel.



Thanks for the Replies
 

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ok mark,thats 3 in the club,me you and don....

any of you guys in the hot states notice any difference..

southern ca

fl,tx.az ?
 

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A further possibility is that my battery has recently run dry twice in the past six month (5 of the 6 cells but it still started) . It was refilled and charged, starts the bike fine etc. Does the somewhat weakened state of the battery severely effect the running of the bike.




This is not a good sign.Usually a symptom of a weak charging regulator.As they are a combined unit it's best to replace as a unit.You can use any decent 12v 3 phase Regulator/Rectifier like these if you cannot find a decent 2nd hand one,



http://cgi.ebay.co.uk/TRIUMPH-REGUL...95?pt=UK_Motorcycle_Parts&hash=item4aa74865ab









Particularly at night, the engine does not seem to get very hot. Even after a long pretty fast run I can keep my hand on the cylinder heads for quite a long time without discomfort. Back during the hot days I measured the temp with a laser temp gauge at various point on the cylinder head and it read a consistent 170-175 degrees after a good run.



As per other post you should not be running without a thermostat.It performs several tasks including quicker engine warm ups to prevent excessive fuel use and lower engine wear and keep the engine at it's optimal running temperature alongside the cooling system in general.



There should be no noticeable changes in fuel consumption if all of the above are optimal.There is a need to change mixtures depending on higher than normal atmospheric pressures above sea level but your plugs should tell the story of what the engine/Carbs need.



Also weak coils will be affected by large temperature differentials and will be especially affected,if weak,by high temperatures.





I would also check and clean ALL electrical connections and grounds and check for any wires/cables that show any signs of melting/Heat damage on the outer sleeves.









HTH
 

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Discussion Starter · #11 ·


A further possibility is that my battery has recently run dry twice in the past six month (5 of the 6 cells but it still started) . It was refilled and charged, starts the bike fine etc. Does the somewhat weakened state of the battery severely effect the running of the bike.




This is not a good sign.Usually a symptom of a weak charging regulator.As they are a combined unit it's best to replace as a unit.You can use any decent 12v 3 phase Regulator/Rectifier like these if you cannot find a decent 2nd hand one,



http://cgi.ebay.co.u...=item4aa74865ab









Particularly at night, the engine does not seem to get very hot. Even after a long pretty fast run I can keep my hand on the cylinder heads for quite a long time without discomfort. Back during the hot days I measured the temp with a laser temp gauge at various point on the cylinder head and it read a consistent 170-175 degrees after a good run.



As per other post you should not be running without a thermostat.It performs several tasks including quicker engine warm ups to prevent excessive fuel use and lower engine wear and keep the engine at it's optimal running temperature alongside the cooling system in general.



There should be no noticeable changes in fuel consumption if all of the above are optimal.There is a need to change mixtures depending on higher than normal atmospheric pressures above sea level but your plugs should tell the story of what the engine/Carbs need.



Also weak coils will be affected by large temperature differentials and will be especially affected,if weak,by high temperatures.





I would also check and clean ALL electrical connections and grounds and check for any wires/cables that show any signs of melting/Heat damage on the outer sleeves.









HTH


Shep,



Thanks for the response and sorry I've not gotten back quickly. I take care of and help as best I can a Burmese refugee family to the north along the border. Its been very cool in the mountains and without much for housing, food and clothing, I do the best I can on very limited funds. Just some old blankets, jackets and a bit of food, not much, but it does help.



I did get the Thermostat back in and it is clearly running hotter. Now, if I could just find that laser temp gauge to get a reading. I'll take it on a longer run soon and pull the plugs and check the condition at that time.



As for the battery charging issue, I put my voltmeter on the battery and got about 12.5v not running but only about 13.8 at 3-4000 RPM. Not in the 14.5 I should be getting and used to get. Would a weakened battery show itself this way.



I've not had time to check the Rectifier/Regulator as yet. I've got the yellow Stator wires soldered together now due to a previously melted connector. I'll be pulling that apart soon and check both the stator and Rectifier/Regulator unit. I will report back with the readings. If the Rectifier/Regulator is bad, are CDI and TI ignition models interchangeable? Mine is currently TI but there are more CDI models over here for possible spares.



Again, thanks to all responders and your PM Shep.



Mark in Thailand
 

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ok mark,thats 3 in the club,me you and don....

any of you guys in the hot states notice any difference..

southern ca

fl,tx.az ?




yep higher idle in the winter than summer



summer is 1100 and winter is close to 1500 if i take it for a run around 100mph its around 1300 so i thought it was a issue also



and my mpgs have stayed the same so no change there
 

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Can/should I use a silicone gasket maker instead without detriment?


You could, but if you can find a Honda car dealer near you they'll have the gasket just as any auto parts store will.



If I recall it's the same thermostat that goes into a 1980's Honda Civic or something like that.
 

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yep higher idle in the winter than summer



summer is 1100 and winter is close to 1500 if i take it for a run around 100mph its around 1300 so i thought it was a issue also



and my mpgs have stayed the same so no change there
thats 4 of us
 
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