The update on our Yamaha YZ250XR Long Term Test Bike from ADB issue #435
New Toy In The Cave
Total Hours: 2
Mods this month: Relocate switchblock, install hour meter
Mods next month: Rec reg, new grips
It’s pretty special having a new dirtbike in the man cave and it’s extra special when the Interior Minister can’t say anything about it because it’s a long-termer. She did also notice the almost-new hardtail mountain bike in the cave though, thanks to one of her advisers. Thanks, Patrick.
I was lucky enough to pick up our YZ250XR (the R is for the version with lights) directly from YRD in Victoria, which is installing the optional LED kits on behalf of Yamaha Australia before the bikes are shipped back to the warehouse, three-month parts warranty still intact. YRD uses a UFO Stealth headlight assembly, folding mirror and handshields while the wiring loom, switchblock and taillight assembly are YRD components made overseas to its specifications.
Considering the YZ250 has no battery, it’s a very clever bit of work involving a replacement OEM stator with rewound coils to power the lights and a capacitor to provide power for the conventional horn. Hold the button long enough with the engine off or at idle and the horn will run out of juice fairly quickly but its legal for rec reg. The brakelight switch and wiring loom are tucked away nicely and the whole kit weighs less than 1kg (taking the bike to 105kg wet) and costs just $500 extra, so it’s hard to understand why you wouldn’t have it fitted from new, if only for those late-evening runs back to the ute in the dark.
The switchblock is a little vulnerable up on the ‘bar so we’ve already moved that inboard on a bit of handlebar tubing mounted to the inside of the UFO Stealth left fork mount bracket. We’ve also removed the plastics and tank and given the frame agood spray with Matrix 1.7 Cleaning Formula Six Motorcycle Pre-Ride Treatment before checking that everything was torqued up to spec. It was also a good time to locate the fuses??
WIRING DIAGRAM
YRD supplies a wiring diagram for the kit which you can tuck into the Owner’s Service Manual you get with the YZ250, for hours of entertainment when it’s pissing down rain. A Yamaha Hour Meter has been cabled tied in place to keep track of our service intervals as the factory mounting bracket is on back order.
The only thing we didn’t like the look of while the Yamaha was apart was the oiling of the air filter, which was barely tacky from the factory, so we had a fresh go at that. You just don’t know how long ago the filter was oiled unless you have the build date or the dealer has obviously re-oiled it.
First order of business for the YZ out in the dirt is to get a fuel consumption figure, as Editor Mitch is a little nervous about the range generated by the Keihin PWK38S carburettor and stock eight-litre tank. There’s already a fairly lengthy accessory list from GYRT (see breakout), including a 12.1 litre tank which looks like it might be the same one fitted to the WR250Z way back in 1997. There are also 11.7L and 14.8L options from Clarke and a 12.1L job from IMS in the USA, thanks to the YZ250’s lengthy production run. We’re leaning towards the mid-capacity option from IMS depending on how thirsty the bike is when we clock the kays with a GPS.
Mitch also is worried about cooking the stock brakes in the High Country and the cooling system in trailride traffic. The GYTR 270mm front disc and solid rear rotor should take care of the anchors if it turns out to be a problem. American Dirt Bike magazine fitted a Boyeson Supercooler waterpump impeller and cover to its project YZ this year but there’s probably a thermofan kit out there somewhere if we’re going to spend lots of time in traffic. The other interesting thing Dirt Bike did was fit a Rekluse 3.0 EXP auto clutch, which might just save the kicker leg a bit of work.
In the meantime, we’re lining up the YZ250XR against the electric-start KTM 250EXC for a full comparo. It will be interesting to see how it stacks up.