Author Topic: 1981 Honda NA50 Express II  (Read 717 times)

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Online seanbarney41

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1981 Honda NA50 Express II
« on: February 26, 2024, 09:46:34 AM »
Working on one of these for a friend...All seems good except for an electrical problem.  The headlight does not work.  It seems that Honda powered all of the lighting off the battery (6 volt) except for the headlight.  I believe the headlight is powered by a separate coil in the alternator.  It is supposed to always come on when the engine is running and switches only between low and high beam. 

Tested the coil for continuity, got 0 ohms, so good there?  That is what service manual specified.  Tested for voltage at headlight leads and only see brief spikes of up to 2 volts. 

Honda only ever sold the whole alternator assembly and of course those are nla.  So used parts its probably gonna have to be...but the coil tests good.  What else could it be?   The rotor has lost magnetism?  Then how does the engine still run?

I think this system may be very similar to some of the more popular little Honda's, like ct70 etc.  Hoping somebody here knows a lot more than me!
If it works good, it looks good...

Offline Don R

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Re: 1981 Honda NA50 Express II
« Reply #1 on: February 26, 2024, 10:17:35 AM »
 It has me wondering if any parts from the clone engines fit?
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Online seanbarney41

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Re: 1981 Honda NA50 Express II
« Reply #2 on: February 26, 2024, 10:42:50 AM »
Well, the big obvious one, is this little Honda is an oil injected 2 stroke...whether that has much impact on the electrical components? not sure..   Guessing the rotor needs twice the ignition pole points?
If it works good, it looks good...