WR 2-stroke Headlight Wattage, Voltage?

WR250 1997 - Not sure what wattage bulb I need. Probably same as an IT or whatever. The light I have fitted is off a 4 stroke TTR and the bulb looks like a car one. 60/55 watts. It runs very dim. Does any1 have a 2 stroke yamaha and what wattage is it thanks

Edit: Are they 6-volt ?

After going to multiple automotive shops who had no idea and had hardly anything remotely close I took a stab and ordered a 35 watt from Yamaha which will fit right into this TTR reflector. They reckon nobody has ever bought one of these bulbs from there and were so surprised I couldn't find one elsewhere that they even rang around before ordering it.

I believe the output was around 35w. for the WRs.

I finally have everything connected with 12v bulbs and there is not enough power to run more than like a dim indicator and a super dim headlight. It is putting out about 5.7 volts with everything connected so i'm thinking the 2 stroke WR must be SIX volt not 12??:D Could be time to source some 6v bulbs..

is the lighting coil on it/ voltage regulator, working properly , may be bad. regulator is cheap to try about 13.00 almost all 2 strokes are 35 watt out of the bag.

Hi there is no regulator anywhere and I'm getting just under 6 volts with headlight which is always automatically on so I shouldn't need a regulator.. the lighting coil would be running pretty reasonably if this bike is supposed to be 6 volts?



Contrary to popular perception, the stator (lighting coil) has no bearing on whether a lighting circuit is 6v or 12v. The actual lighting (6v or 12v bulbs) that you hook up to the stator determines this.

As others in this thread have said, the 2T WR lighting coil can handle a 35w bulb and that's about it. Since you mentioned you were only seeing 5.7v with a 35w draw it leads me to three questions.

First, are you measuring voltage at idle or with some rev? At idle the voltage always runs very low. On 2T's WR's, at least 1/4 to 1/2 throttle is nesessary to bring a 35w bulb up to full (+12vac) brightness.

Second, how do you have the bulb wired? When looking at your bulb from the back, the left prong is ground, the top prong is low-beam and the right prong is high beam. The left prong should be attached to chassis. Either the top prong or the right prong (not both!) should be attached to the yellow wire from the stator (depending on if you want to run the low beam or high beam.) One of these two prongs from the bulb must be left unconnected if you're not running a high/low switch. You should also have a 12V AC voltage regulator wired in to avoid blowing out the bulb filament at high RPM's.

Last question, are you measuring for AC or DC? You should be measuring for AC only.

I just got this very nice 93 WR and was wondering about the differences from the YZ of that year. I haven't rode it much but it is fast from seat of the pants. Is the tranny a wide ratio? Will an Acerbis Cyclops work. I'm getting it ready to get it on the road, and already put a PC Shorty 304 on it and some oversize bars. I can't find a lot of info on it, so I'm looking for anything.



Yep they are wide ratio hence the WR. What is an Acerbis Cyclops? That bike looks in amazing condition

Moleculo, thanks for your reply!

Are you measuring for AC or DC?


First, are you measuring voltage at idle or with some rev?

2 v idle, heck of a lot more revving.

I tried something. Huge brainstorm. Took the tail light globe out, it was 21 watts. No wonder nothing will work. Well that sure helped. Nice bright headlight instead of two lights hardly shining at all. I was wondering just why and how was it possibly that ridiculously dim though, and figured that it's because lights have more resistance when they aren't bright. Went and bought 5watt indicator ones and a 25watt headlight. ALMOST runs them. I will try an LED in the tail light

No regulator needed right now since need more power but maybe with LED's. The LED indicator's use a different relay too if I go that way.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now