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Motorcycle Repair/Headlight Burning Out


Hey Bill,

I have a 1975 XL250 and the headlight is burning out. I've done quite a bit of reading online and have a fair idea of how the power gets to the headlight. My understanding is that it's AC power straight off the stator. Including on your site, I've read about the existence of a 3.61 ohm resistor that helps to maintain proper voltage to the headlight. Funny thing is, I think I know where the part used to be on my bike. If I'm not mistaken, it's a small harness that comes out of the back of the headlight with a white wire. On my bike, there used to be a small, cylindrical thing attached to that harness. It was about two inches long and the diameter of a pencil. It seems to have "left the bike on it's own." The harness is still hanging there, just no resistor attached anymore.

Could this be my problem? Assuming it is my problem, where in the heck can I find a replacement part? I'm just not having any luck finding anything but rectifiers and voltage regulators. I saw where one guy tried to make one with a modern day resistor, but he wasn't having a lot of luck with that. Any ideas?     Ken

Ken, yes the resistor is necessary to control excess stator output current.

Lucky you..... They are generally hard to find... 35400-329-671 is the part number

Bill Silver  

Motorcycle Repair

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Bill Silver


Need help with vintage Hondas from the 1960s? I am an expert with 250-305cc bikes in particular and most all of the other pre-91 models, in general. I do NOT claim to have a great deal of experience on Gold Wings, Cruisers, ATC/ATVs and dirt bikes.


I have owned/ridden/maintained Honda motorcycles for 35 years. I have written five books on Honda repairs and collecting. I was a service manager for two Honda shops back in the 1980s.

VJMC (Vintage Japanese Motorcycle Club) of North America

VJMC newsletter, as editor for two years and as contributing editor currently.

3 years auto shop in high school, teacher's aide in Automotive Technology in Jr. College, Diesel mechanic course in college, self-taught mechanic and automotive writer.

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