'06 WR450F Electrics

New to dirty bikes, and recently got a 2006 WR450Fv ...its been into a local shop for some necessary work that I didn't want to do (too cold outside to work on it here). Part of the work/parts was a new battery, which I have found to discharge within a few minutes of running the bike, during a combination of high revs idle with the cold start enrichment engaged, followed by a bit of "warmed engine" condition with enrichment off, then normal idle rpm followed by a few minutes of low rpm riding....grand total of +/10 minutes run time = dead new battery. I charged the bat. and tried again with metering in place and found that at low rpm idle I was in discharge mode with the system supply a lowly 9V .. BUT.at +/-5000rpm I got a reading of 14V.


I would like to know from other WR450 owners, ..is this low rpm discharge a normal condition.. which is the story the shop tech was giving me ? What charge voltage are you seeing at engine idle rpm?. 

Something is not right. You should be just barely breaking even at low rpm (11.9 - 12.5 V) and 13.5-ish at WOT

The unit of the left side of the crank that makes the electricity should be OK due to the fact that at WOT you have 14+ V .....that s good

If the stator was kaput you'd get low voltage all the time


I'd say there is a 90% chance the voltage regulator / rectifier on your bike is bad.

Unfortunately I do not have access to manual here so this is as far as I can go

But I'd place high odds on that unit being defective

I'm pretty sure there is a diagnostic procedure in manual for testing it even


Your best bet right now is get factory yamaha manual (not a chitlin's)

They even have it online you can buy

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