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Discussion Starter · #1 ·
I went for a ride and picked up my uncles infrared thermometer today, and as soon as I got home I shut down the bike and shot a point right in between the aluminum exhaust flanges and the cylinders. Left side registered 185F, right side was 143F. I think that is a big difference and maybe pointing to a lean condition one one side versus a richer side.



Has anyone used an infrared thermometer to make a correlation between the temperaure and 'the perfect burn' on a spark plug?



I know Shep has a Gunson Tuner, and wonder if he were to confirm a perfect burn, go for a ride, and then measure left & right and see what the temperature of each is in the spot I mentioned. If you get this Shep, let me know if you would participate and let me know! It would be awesome to have a digital pic of the Plugs with a Gunson Blue Spark showing showing the ideal burn color, and have the couple data points for the temperature.



The spot I measured on each side...



 

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Discussion Starter · #3 ·
sorry but I had to edit so it was clear where I was measuring...I think we might do some learning and fall onto some sort of average and it may help to be a guide for better tuning of the CX's...
 

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Discussion Starter · #5 ·
I was told yesterday that Larry has done some playing around with this.


I think it would be awesome to take a handful of those with the most familiarity with these bikes, have them agree on maybe 15 to 20 locations on a motor, and all collect the data, take some averages and see what the outcome is.



In my mind some baseline details would have to be agreed like a tuning procedure that everyone would follow for the test, all would measure the same spots, carbs would be sync'd, etc. I know I plan to play around and see what I can come up with!!
 

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I have an Infra red temp gun.Both my CX500s have a running temp at the back of the cylinders on the water jacket point of approx 85 Deg C @ idle.I choose this point so as not to get false readings from things like the exhaust heat at the front.

These temps are what I would expect as they are the same for most Internal combustion engines and match close to the opening temps of the Thermostats hysteresis.





Common causes of mismatched running temps.



1:Cooling faults



Blocked/inefficient cooling system especially in one side.Do a cooling system flush including rad off and soak/flush through if possible.



2:carburetion faults.



Weak mixture

Incorrect Float levels

Air leaks

Partially blocked slow speed idle circuit.



3:Ignition

Bad plug/Plug cap/Coils/Leads(HT and LT).



Note:Single skinned down pipes will show a Blue or Gold colour if the engine is running lean.It's a common mistake to believe,"Golding" means too rich.Different metals behave differently under high heat conditions of a lean mixture.I have had both colour faults over the years and verified the high temps/lean mixture conditions with an Infra red temp gun(Very useful tool).



http://shop.ebay.com/i.html?_from=R...=LH_DefaultDomain_0&hash=item2a10d6783b&vil=1
 

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I think it would be awesome to take a handful of those with the most familiarity with these bikes, have them agree on maybe 15 to 20 locations on a motor, and all collect the data, take some averages and see what the outcome is.



In my mind some baseline details would have to be agreed like a tuning procedure that everyone would follow for the test, all would measure the same spots, carbs would be sync'd, etc. I know I plan to play around and see what I can come up with!!
If someone wants to lay out the measuring points and parameters for this I'll add the figures from my bike to the pool.
 

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There are only 3 spots I need and use.The points posted above on the cooling jacket for each cylinder,the Drive box after a ride.No need to over complicate.



Mine read approx 85 Deg C for each cylinder(Both my CX).



35/40 Deg C drive box after a ride depending on the day's ambient temps.



These tell me if my cylinders are level and correct and that my drive box is not overheating.If the cylinders aren't level there's a fault,see above,



PS

You might be surprised how cool the engine oil is at the filter/Sump




HTH
 

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Discussion Starter · #10 ·
thank you very much for the details Shep--I appreciate you sharing your experience and I agree to not overcomplicate things...I guess back to the original question. Can you post pics of your plug color Shep, and for grins, post your temps at the point I measured? That would be AWESOME.



My plan now is to ride for about a half hour or so, roll in to the shop, shut her down and log the temps in the spot in show on the chart, as well as measure the three other points you mention. then take pics of the left & right plugs to see what the color looks like.
 

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What about at the header with a correlation to plug colour to find out the variation on combustion temperatures in relation to mixture.


Your spark plug colour will tell you what you need to know
 

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thank you very much for the details Shep--I appreciate you sharing your experience and I agree to not overcomplicate things...I guess back to the original question. Can you post pics of your plug color Shep, and for grins, post your temps at the point I measured? That would be AWESOME.



My plan now is to ride for about a half hour or so, roll in to the shop, shut her down and log the temps in the spot in show on the chart, as well as measure the three other points you mention. then take pics of the left & right plugs to see what the color looks like.


I could do but it's bit pointless.My plugs are always Tan coloured and always will be.That's the correct colour they should be.If they are not I address the problem.



If I had to pick the most common cause for me of the cylinder temps imbalance it would be Carb float heights going out.



As I've messed with a lot of engine builds and carb re-builds this has cropped up more than once with me swapping carbs to test them as I like to keep a spare set ready to go in.



I've ended up with a lot of spares that I service in the dark months like I have 3 oil pumps with chains in Zip lock bags,two or three serviced starter motors and a complete spare engine that needs stripping as one of the Oil rings on a cylinder has gone.



Tip:If you see a basket case engine going cheap and close,grab it.You can gets lots of good stuff off them
 

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Discussion Starter · #15 ·
I could do but it's bit pointless.My plugs are always Tan coloured and always will be.That's the correct colour they should be.If they are not I address the problem.


it would be helpful for ME to see what a 'perfect plug/shade of tan' looks like! To you with your wealth of experience, its common place, to the newb, well that sort of info is like Gold! If you could it would be awesome, if not I understand! Thanks again for sharing Shep!
 

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it would be helpful for ME to see what a 'perfect plug/shade of tan' looks like! To you with your wealth of experience, its common place, to the newb, well that sort of info is like Gold! If you could it would be awesome, if not I understand! Thanks again for sharing Shep!


OK.Next time I go out for a ride I'll take my Temp gun with me.I always have a plug spanner in my tool kit anyway.Where do you want the temps taken?The only place of relevance to me is what I have already posted e.g at the back of the cylinder in the middle of the Jacket a couple of inches down from the head cover seam.



Your plugs should look like this when right,



http://www.spark-plugs.co.uk/pages/technical/diagnosis.htm



http://www.4secondsflat.com/Spark_plug_reading.html
 

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Discussion Starter · #17 ·
So as a follow-up to my measured temperatures at the spot marked by my red dot...

On the left would correlate to 185F, and the right would correspond to 143F.



Your thoughts on the color, left versus right?



 

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Discussion Starter · #19 ·
There's not enough difference to worry about and not enough miles on them to really tell.Enjoy the ride


Previously these were lean by comparison and had a tiny bit of tan to them, but nowhere near as much as the most recent pic.



These pics were taken after about a 45 mile ride, average speed of around 35 to 40mph. I enriched the right cylinder a tiny bit, and used the thermal gun to compare temperatures on opposite sides of the motor...most times the temps were within 5 degrees F of one another.



I hooked up the manometer last night and my carbs were terribly out of sync--to the point where I had to hit the kill switch for fear of sucking fluid into the bike. I dialed them in to +/- an inch or so and it sounds like a different bike.



The biggest difference I noticed after this round of tuning is the Tach response...after snapping the throttle to rev the motor there was zero hesitation, and she returned to 1100 on the dot with the digital tach to confirm it. Previously she would lope below 1000 and work her way back up.



I can't wait to test ride her this evening and check the color of the plugs again.



We had some threatening skies last night, hail the size of quarters, and some of the most meanacing clouds i have seen in a long time. We actually took shelter. Tonight the forcast is clear for the PM hours!!
 

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I can guarantee you there are millions of bikes out there whose carbs are not in balance.Like clutch wear it can be gradual but when you get the engines fully back to factory specs they are a fantastic mid-range power-plant and balanced carbs are a big part of this but should only be done as the last thing when all things are correct.



I still marvel some times when I'm pulling up some of my hills and dales the bottom end grunt and then smooth power-band these bikes have for their size and a 30 year old+ design
 
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