450F WR450F headlight drawing too much volts

My WR keeps blowing bulbs, only two so far, and when I checked the voltage with my meter it said it was 20 volts. That's not good when the bulb is only rated for 12 volts. All fuses are good, even though that really wouldn't be the problem. I also went through and checked for any shorts, there were none. Anyone know what's going on? Is it a simple fix or will I have to do some work?

The bulbs are Philips H4 12v 55/60watt.

Thanks in advance :thumb:
 
Voltage regulator/rectifier maintains the 15Volts you require...
Could be bad... -BIG DAN:thumb:

Ah yes the regulator :thinking:. Is there a way of checking that? I really don't have the $120 right now to drop on a new one. Ill start by checking all of the wires coming from it to make sure they are still in one piece. Thanks for the advice.
 

SRAD97750

Moderator
Staff member
OK, so 04-06 are the same regulator.
Testing resistance across the wires that go to the battery SHOULD be 0.224 - 0.336 ohms, any more and that's your problem.
http://www.ebay.com/itm/04-Yamaha-W...Parts_Accessories&hash=item35cbecb82c&vxp=mtr
Used... came off running bike...

http://www.ebay.com/itm/FSW-Yamaha-...Parts_Accessories&hash=item56586a6bdb&vxp=mtr
Known Good regulator.

http://www.ebay.com/itm/2003-Yamaha...Parts_Accessories&hash=item2c731ba880&vxp=mtr
Check your connectors and see if this might fit. It's an 03 though...
-BIG DAN:thumb:

Oh. Don't ride it. You'll possibly fry your battery.
 
OK, so 04-06 are the same regulator.
Testing resistance across the wires that go to the battery SHOULD be 0.224 - 0.336 ohms, any more and that's your problem.
http://www.ebay.com/itm/04-Yamaha-W...Parts_Accessories&hash=item35cbecb82c&vxp=mtr
Used... came off running bike...

http://www.ebay.com/itm/FSW-Yamaha-...Parts_Accessories&hash=item56586a6bdb&vxp=mtr
Known Good regulator.

http://www.ebay.com/itm/2003-Yamaha...Parts_Accessories&hash=item2c731ba880&vxp=mtr
Check your connectors and see if this might fit. It's an 03 though...
-BIG DAN:thumb:

Oh. Don't ride it. You'll possibly fry your battery.

My brother has an 03, he is in Vegas for the weekend so ill just steal his and see if it fits. Thanks for all the help, ill check and see if its my problem tomorrow and get back with ya.
 
OK, so 04-06 are the same regulator.
Testing resistance across the wires that go to the battery SHOULD be 0.224 - 0.336 ohms, any more and that's your problem.
http://www.ebay.com/itm/04-Yamaha-W...Parts_Accessories&hash=item35cbecb82c&vxp=mtr
Used... came off running bike...

http://www.ebay.com/itm/FSW-Yamaha-...Parts_Accessories&hash=item56586a6bdb&vxp=mtr
Known Good regulator.

http://www.ebay.com/itm/2003-Yamaha...Parts_Accessories&hash=item2c731ba880&vxp=mtr
Check your connectors and see if this might fit. It's an 03 though...
-BIG DAN:thumb:

Oh. Don't ride it. You'll possibly fry your battery.

Alright, I went across the battery connections (with the battery unattached) and I got a reading range of .45-.55. Im sure the regulator is bad now. I am going to try connecting my brothers that I stole last night and see if that one will do any good.
 

SRAD97750

Moderator
Staff member
YEP, that extra load will cause the stator to provide more power.
FYI, I like to think of electrical systems as a "demand system." It'll only give what is asked of it. If the resistance is greater than normal, then the output will be greater than normal. It only does what it's asked. -BIG DAN:thumb:
 
Alright, update time.

Thanks to a motorcycle lift, a big fan, and some open windows I was able to test my headlight in the garage. Its not the most practical and safest thing to do, but what else is there in the middle of a blizzard. I put the bike on the lift with the fan on the radiators and the windows open for the exhaust. Started the bike up and turned the headlight on. I first tested it on idle for a while and then very slowly started moving up in RPMs. No blown light bulb and no shorted wires. The new regulator works like a champ. Thanks for all the help and advice. :thumb:

P.S. I was unable to win the eBay items so I went on a web search for a new one. I found it in an unusual spot, but if you are looking for cheap OEM parts for your Yamaha with fast and cheap shipping try http://www.boats.net/parts/search/Yamaha/parts.html. I got the regulator for $95 including shipping. Everywhere else I looked it was close to $120.
 
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