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Discussion Starter · #1 ·
Went to ride the bike today and found my battery was completely dead. It was a walmart special, but it got me thinking that the charging system may not be functioning adequately. When I was riding it yesterday it ran great, stalled idling a few times however (had to keep reving it at red lights). Today I got myself a higher quality battery and I'll go riding tomorrow, but is there a quick and easy way to test the charging system without needing both a volt and amp meter?
 

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You'll need at least a cheapy multimeter ($6 at Harbour Freight) that will read both AC and DC voltages..... With alternator unplugged from harness, read AC volts across Yellow and Pink wires... Voltage should climb as revs do.....but should be at least 25/30VAC at idle, preferably higher....
Plug alternator back in to harness,... restart bike.... Read DC volts across battery terminals.... Should read 11.something immediately after e-start, and climb with revs, but stop at somewhere around 13.7 to 14.5 VDC..... You SHOULD (theoretically) be getting 12V at idle once the bike is warm (lights off)...If not, set idle up until you do IF it remains below 1600 RPM...(recommended idle speed is 1200 to 1300)... If it requires much higher than that, you will be into the timing advance range and changing (advancing) the idle point timing...(not recommended).... and your charging system is weak....
Please post your results for comparison by others...
 

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Discussion Starter · #5 ·
Ok, I went with the $20 radioshack digital multimeter (harbor freight is on the other side of town). After kickstarting and idling around 1400rpm, I was getting around 16-18 VAC from the alternator. As I reved up, it climbed to around 30-32vac at between 2000-3000rpm. Might have gone higher with the rpms, but with no mufflers, my neighbors wouldn't have appreciated it. Plugged it back in, started up, got 12v at the battery no prob. So, what can I do to increase the charging? The battery wasn't dead, but I can see why it doesn't like to idle for more than a few seconds.
 

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Sounds like your alternator is nominal but OK (those readings are typical across yellow/pink)...You CAN put it in constant "higher charge" mode by permanently connecting the white alternator wire to the yellow wire...(ACV output readings should rise by approximately 50%).....
I'm also assuming you CAN get more than a 12VDC. reading at the battery while revving it up...IF the DC voltage there doesn't also rise with revs, it could be the rectifier or regulator that is defective....
Your idling problem could then be anything from low compression to dirty carbs, to imperfect timing or bad advance unit, to a fuel supply problem, bad coils, etc.....We'll just have to eliminate them one at a time...
 

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Discussion Starter · #7 ·
indeed the 12v does rise a little when revved up. I had the timing and points professionally calibrated, I think they also checked the carbs, which were rebuilt prior. Basically it runs great until I come up to a red light. As I down shift and slow down, I can tell the engine is starting to struggle when I pull the clutch. After I come to a stop, usually in 1st gear with the clutch pulled, it doesn't want to idle at all, revs up fine though. For the time being, I'll just adjust the idle speed a little higher. Another thing that might help is after it does stall, it usually takes 5 minutes worth of kick starting to get it going again.


edit: Came back from the store....a guy on a Harley suggested it's stalling because it's floodin', perhaps this is a carb issue after all, maybe when the engine is warmed up?
 

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A little?, or does it definately make it to 13.5+V?....
Carb flooding could be an issue,...or stuck advance unit, ... as could compression....... 170 PSI is the "standard spec" on the 360's... Below 155 is not good....They'll run as you discribe at 120 to 130.
 

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Discussion Starter · #10 ·
I'll have to track down a compression test kit at some point, the oil covered spark plugs suggest poor compression as well. Yea it hit 13v, probably would have gone higher if I continued to rev up the engine. By professionally calibrated, I'm referring to the mechanic that works mostly on ATV's and dirtbikes (2nd Chance Cycles, walkertown, nc). Is there a way to test the advance unit?
 

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BerryDuffman said:
By professionally calibrated, I'm referring to the mechanic that works mostly on ATV's and dirtbikes (2nd Chance Cycles, walkertown, nc). Is there a way to test the advance unit?
Yes, in the same link I gave you a couple of posts ago..............you didn't bother to read it, eh??
 

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Clutch drag sounds like a possibility to me too.. If it's struggling to idle after pulling in the clutch. I could be way off though..


GB :mrgreen:
 

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Discussion Starter · #13 ·
Clutch drag is possible as I did have the front sprocket cover off when I did the chain. Looks like I have a nice checklist to run down this week :)
 

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If you decide to check out the clutch adjustment and still have a problem then you might check these:

I'm not familiar with the 360 so someone correct me if I'm guiding him in a wrong direction on any of this.. :oops: Of course, listen to Bill and Steve's suggestions firstly.. Their brains are HUGE and packed full of knowledge on these old bikes! ;)

Check for part #21 in this fiche
http://www.cmsnl.com/honda-cb360-us_mod ... E++09.html

Check for wear on the long steel rod - part #10 in this fiche
http://www.cmsnl.com/honda-cb360-us_mod ... E++07.html

After being sure your clutch cable adjustment is correct of course...


GB :mrgreen:
 

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oil fouled plugs and your idling/starting problems suggest low compression....I'd check that first!......
 

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Discussion Starter · #16 ·
I'll adjust the clutch as per what the manuals say just to rule that out; seems to run ok in neutral, it does stall eventually, but the engine doesn't sound like its struggling. I'd bet money my compression will be on the low side though, this bike has had a rough life. Perhaps low compression with a touch of clutch drag; I'll find out this week. Looks like a trip to harbor freight is in my near future. Hopefully I can walk out of there without buying everything I'd like :lol:.
 

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• Digital meters can be a bit strange when set on DC to measure charging voltage when there's AC current present (failed rectifier diodes), and they don't all seem to respond the same way. Some seem to give an acceptable reading anyway, but - of course - AC won't charge your battery. Analogue DC meters, in my experience, won't read AC current. If you read battery voltage after a long ride right after shutoff, you should have well above 12 volts, maybe as high as 13.
• If your clutch is dragging, shifting (especially low gears) will be difficult. Neutral to first will engage with a strong clunk, and you usually won't be able to disengage from first while stopped with the motor running.
• Do a ground-up tune up. That eliminates the most probably issues and helps with diagnosis of esoteric problems. High float levels/leaking float valves could be giving you the idle problem.
• The oily plugs almost certainly indicate internal motor work in the very near future and may stem from the same problem as gives you your idle difficulties. A compression gauge isn't exactly a high cost item, and you'll still be using it in about an half century.
 

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This guy has probably long since solved his charging system problem, but for anyone else who stumbles across this thread:

Your charging system should never go substantially over about 15 volts. If it does, your regulator or rectifier is hosed, and it will kill the battery (not instantly, but eventually). In the case of generating twice the rated voltage, I would tend to think it is a problem with the rectifier, but it could also be an issue in the stator.
 

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Does the test procedure posted at the start also apply to my CL175 which I believe doesn't have a voltage reulator?
 

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Malcolm.... Your 175 does (should) have a regulator..... ( aluminum rectangle with short sides having triangular mounting tabs...Three wires; green, yellow and Black, and should be on the back side of the centerpost.....

Sharkmonkey.... The AC output HAS to be double (or more than) what the required DC voltage is as each diode in the rectifier only allows (the correct directionality) half of each power wave to pass through it......Plus, there are resistance losses too....
 
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