Tutorial - YZ450F (06 & up) Electrical System For Lights

Guys, thanks for the incredibily helpful thread. Hoping for a little clarification:

-- can I run a 35W headlight, 1W LED taillight, K&S LED DOT flashers using the Moose 50W stator, a Trail Tech reg/rec and a battery just to pass inspection? I realize that the battery will drain but I have a trickle charger for in between rides. I think in MA I need all lights to work when the bike is not running. I could run the horn off a separate little battery (Sicass Racing carries self-contained 12V horn systems).

-- after inspection, I could change out the 35W headlight for an HID set up (non-DOT).

I think you'll be fine with that

Thanks Swatdoc. Any battery suggestions? Can I use one of the Trail Tech NiMH batteries or does it have to be a traditional lead acid 5 lb. battery? It will be hooked up to the stator and might even even recharge once I swap to a lower wattage headlight system.

-- can I run a 35W headlight, 1W LED taillight, K&S LED DOT flashers using the Moose 50W stator

I have that stator but I run the typical 12v tail/running/license plate/brake assembly with a 35w headlight and a 12v horn with no directionals and the headlight is barely on at an idle. At night at a stop light I have to keep the rpm's up quite a bit to make it look somewhat legal. I'm curious if your 1w LED taillight will give you a little more boost in the ele. system as apposed to my (8W. I think) which drains more from the stator?

TNL - a typical tail/brake light bulb like an 1157 draws 20 watts for just the tail light light and 25 watts when the brake is on. An LED tail light would help considerably, as it's only 1 watt tail and 1.4 watts brake light. You are definately overtaxing your system, big time - especially since you're running a battery - that means you're using a rectifier, which drops the wattage down to around 35 or so. So you're pulling 55-60 watts on a system that only puts out about 35 at half to full throttle. your battery is struggling to make up that much difference.

Lumpy - call trail tech to confirm this, but I don't think you can hook up NiMH or NiCD's to a motorcycle charging system. I think you can only do that with a lead-acid battery. Again, i'm not 100% on that - i would call trail tech to confirm, but i think the NiMH batteries require a special dedicated charger and are meant to be used in a total loss type system.

Swatdoc, thanks. That is consistent with what I have always thought. I will talk with TT. Also, there is guy over on KTMTalk named Joe Turner. I believe he might make smaller battery packs that can be charged off the stator. I'll report what I find.

please do - i'd like to know for sure on that

and TNL - just remembered trail tech makes an LED light bulb that is a direct replacement for an 1157 if that's what bulb your setup has. it's only about 8-10 bucks and just plugs right in. real easy for you to convert to LED

i have a 06. im not looking to run a headlight but couldnt a guy just buy a wr flywheel and stator. and the cover if needed? and then do some wiring or buy a wr wiring harness??

yes you can buy all that, but the flywheel won't fit on a YZ crank - it's been tried. You have to get either an entire WR crank, or at minimum get the left side crank half, and replace the yZ left crank half with it. then the WR stator , flywheel and ignition cover will fit. one more thing - the WR stator is not compatable with the YZ ignition system, so add a WR ignition CDI and the wiring harness to your list. Don't for get the cost to split the cases, press off andon the crank halves, then reassembly. easily looking at over $1000

I am going with the Moose 50W stator, Polisport MMX 35W hi/lo headlight (DOT), DOT LED turn signals (K&S) and LED tail light (MotoLED Edge 2). Horn will be a kit from Sicass Racing that runs off a separate battery, though given the infrequent use of a horn I may just end up hooking it up to the bigger battery. The bigger battery will be Turn Tech 5 Ah battery. Here's what Joe Turner from Turn Tech told me when I asked him which size battery to run -- 2.5, 5 or 7.5 Ah battery:

"I think you would only need the 2.5Ah. The 2.5Ah has ~8Wh, which means

that it would run a 40W load for approximately 12 minutes. This means at

normal speeds you would be +/-3W and at idle you would probably be 20W in

the hole (rough guess). This means that fully charged you would have 24

minutes at idle. at normal speeds you would either charge the battery at

3W (~250mA, 0.25A) or worst case if you were consuming 3W you would need to charge the battery at around three hours of use.

The 5Ah would give twice the time, 24 minutes under a 40W load. 48 minutes

at idle, and nearly 6 hours of use if you were 3W in the hole."

Two challenges I see are (1) how to mount battery in the airbox and (2) do I need to relocate the CDI in order to fit the headlight.

Trail Tech told me there are no halogen or HID options for headlights at or below 35W.

lumpy - whats the dimensions and weight of that 5 ah battery? any pics? i couldn't find a website for turn tech

i got this light for if i convert to DC: http://www.trailtech.net/3152-SX.html

only draws 13 watts

this one: http://www.trailtech.net/4212-SX-V.html

puts out even more light and only draws 30 watts

Oh, another thing - it looks as if NiMH batteries CAN be connected to the bikes DC power system and be recharged thru the stator! This per the Trail Tech website. They have a 3.7 AH NiMH battery that weighs CONSIDERABLY less than a lead acid battery would of the same size.

Here's a pic of a 5 Ah battery mounted in the airbox. I bet I could fit the 7.5 Ah battery if I wanted. It went in surprisingly easy. I happened to have a large pipe bracket lying around (bought it at Home Depot a few years back) and it was easy to shape in the vise. Two M5 bolts hold it in the subframe. The subframe is pretty thin -- maybe 3/16", so not much in the way of threads when I tapped it but I think it will be ok.



Do you have any pics of the bike, so I can see the black frame?

Swatdoc, do I need to run a fuse anywhere in the electrical system?

These guys have a complete harness that will work for a YZ.

Not for a YZ, though you could probably jerry rig a harness from a WR or CRF. For the money, much easier to just make one yourself. I did it last weekend in a few hours.

I ran a 5 amp fuse in my setup. Did you see the wiring schematic I did? It shows where i put the fuse.

mxracer - go to photobucket - whole buncha pics of the build under swatdoc

Swatdoc, thanks. My bad, I see the diagram on p.1 of this thread. You have an ac system and I have dc, so I'll just put the fuse between the reg/rectifier and the keyed ignition. I will do a diagram so folks can see what I did. It's more complex given I have LED turn signals, an IC relay for them, hydraulic brake switches for both brakes and turn indicators on my Vapor dashboard.

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