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1970 CB450 charging problems. Just looking for a demonstration how to check the magneto, stator and rectifier, and maybe a quick explanation how to replace them

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Being a 1970 vehicle you have the older copper oxide rectifier,if you have charging problems,that type of rectifier output usually drops to about 1/2 battery voltage. It is located under the seat between the back fender and the bottom bar that the seat rests on,also more often than not, you get a really strong odor of rotten egg smell from a defective copper-oxide rectifier. Solution, replace with a 6-10 amp bridge rectifier from Radio Shack. Your charging voltage should be in the range of 13.8 -14v@ 1500 rpm.

Posted on Dec 04, 2012


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SOURCE: Gsf400 bandit wont charge

If the battery is 2 years old or more it may be bad. Add water to each battery cell so that the plates are covered by the water. Charge the battery with a 1amp or 2 amp charger for about 5 hours. If it will not hold a charge then replace the battery.

At the site below you can download a free PDF service manual for your bike. The manual will tell you how to check the electrical components. It will tell you how to rebuild the engine as well, but save the rebuilding until next month. :)

Please rate this answer. Thanks spooner1401!

Posted on Apr 17, 2009

  • 221 Answers

SOURCE: wire connector between stator & voltage reg/rectifier burnt

your voltage/reg. can be tested in a couple different ways check ground res. check res. then revs. bias on diodes you have ac in dc out it sounds like you may have a diode gone bad allowing ac curent to flow causing the wires to get hot

Posted on Jul 31, 2009

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SOURCE: Alternator not charging battery on getting 11.5

I had the same problem with my 900 that I just bought, the regulator was fried, so the local kaw shop replaced it with a new one off internet, then it promptly fried the new one, upon further investigation the rotor/armature was reading 1 ohm resistance, supposed toread 4/7 i think anyway, had to have alternater rebuilt , cost 370.00 , works fine now.

Posted on Aug 06, 2009

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SOURCE: Battery would not charge while bike is running.

u sure the alternator is producing-hows the wire connections to batery-inspec fuses n other partz of harness

Posted on Aug 24, 2009

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SOURCE: I can't find the oil filter on my 1970 honda cb450

It does not have an oil filter like what you are thinking of. It has a centrifugal oil filter. On the right end of the crankshaft there is a conical rotor. It turns with the crank and dirt particles get thrown to the inside wall of the rotor. The dirt builds up there and is cleaned out with a screwdriver, knife, small scraper, whatever. You will think you are destroying some type of gasket but dirt is all it is. You may need to remove the right side case for full access. I can't remember for sure.Go to for diagrams and parts as available. Please rate my answer.


Posted on Feb 21, 2010

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Check charging system. Charge battery. Could be the stator, rectifier, regulator. Or all. You may have to install a battery tender if you still have a problem. Good luck. Getting stuck in bad places suck.

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Honda cb450 stator test

You should have a 3 phase charging system. Which means you have 3 leads coming out of the stator. They will usually be yellow or white. If you attach you meter leads from lead 1 to 2 you should usually get around .2 ohms. Then do the same check from 1 to 3 and 2 to 3 Then take one meter lead and connect it to chassis ground while touching all the leads , one at a time. If you get numbers of any sort when you're checking the ground the stator is bad. If not then your regulator. The more common problem with Honda is the regulator. Stators very rarely go bad.

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I've got a 07 Grizzly 450 that I just recently purchased, I took it out this weekend for it's first long ride and it quit charging. Where do I start looking for problems? Stator rectifier or both, Also is...

The best way is to purchase the service manual and follow the instructions. Otherwise you can use a volt meter and do the voltage test at the battery while the engine is running is should be 14 volts at 1000rpm. If this doesn't check out, you then have to find out whether it's the stator or rectifier. Check the ac magneto charging coil resistance (right at the coupler) with your testor set to ohms. If this test checks out then its the rectifier, if it fails then it's your stator. The best and safest way is to use the service manual to do any work yourself. Good luck!

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My aprilia rs 125 battery keeps going flat i charge the battery up and last round about 1 mile then gose flat my engine then cuts out i leave for 10mins then it gose again im thinking the magneto as ive...

Hi, Swiftb152 and the usual suspects are:
1. Voltage regulator/rectifier not grounded.
2. Engine ground wire loose or broken.
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For more information about your issue, please visit the websites below. Good luck and have a nice day.
DOWNLOAD 1999 Aprilia Rs 125

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The first things that I would check is the Stator and the Regulator Rectifier. To check the stator and the Rectifier I would suggesting you get the repair manual. The repair manual is a Mechanics best friend. Not all bikes are the same and the manual will help with the diagnostics of both. Most of the time you can buy a manual on CD from ebay for about $5 to $11 dollars which is cheap compared to the paper back price.

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2 Answers

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Need a wiring schematic for the honda cb450 online

Here is a copy from Chilton's CB450, 1970 and above, hope it helps. I had to reduce it to monochrome in order to post it. It was 769K in grayscale.b2bce1e.gif

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