Just bought a WR450 and have a few questions please....

6 replies to this topic
  • S1rst

Posted October 06, 2008 - 04:08 AM


Hi all, im Richard, ive just bought an 08 WR450 and ive come accross this site while searching for info. I must say it looks a great site and full of info!

Anyway, ive seen the FAQ and that answers most of what i needed to know. But i cant seem to find much about reccommended oil. What grade and make of oil would be good for my bike? Its a 2008 model and it had 14 miles on it when i bought it im the second owner, it now has 50 miles on it :bonk:

I know oil changes cannot have a set time limit or mileage put on them, but how often do you guys change yours and how do you ride the bike? I dont ride it that hard really, and wont be racing this one, just using for a bit of fun at the moment as i cant really afford to race again for a while.

Ive always had 2 strokes before and know them inside out but 4 strokes are new to me. What i assume is a catch tank for coolant overflow behind the left side panal, its more or less at the bottom and i can just see the green coolant at the top of the pipe. Is this how it should be or should the level be higher?

Ive also noticed in the spares, some different jets and needle. These are unopened so i assume it still has stock jets? Its had the baffle and restrictor removed from the exhaust and the throttle stop screw taken off, but the grey wire is still connected. It seems ok as it is, but would i actually benefit from removing it as it runs fine as it is now on what i assume are stock jets.

Any other general info and advice welcome because as i said this is my first 4 stroke and i dont know a great deal at the moment.

Thanks in advance, Rich. :lame:

  • face_plant

Posted October 06, 2008 - 08:54 AM


all depends on how you are riding, mine is 1000mi supermotard and 200-300 off road.(just starting to change color)

oil is like shoes everyone's got an opinion
i like klotz 20/50
gear saver 4t is good
yamalube semi syn is also a favorite

grey wire? i cant say on an 08, but my 05 is still intact, didnt like it snipped
here. routine maintainance is cheaper than neglected misuse and KEEP IT CLEAN. a clean bike is a happy bike

  • BajaFool

Posted October 06, 2008 - 12:02 PM


Welcome to Thumpertalk. I own a 2008 WR450F. You can't go wrong using the manufacturer's oil, Yamalube. However, I personally use Maxima oil, Maxxum4 10W40. It is great oil, motorcycle specific and should be available in the UK. The recommended oil change interval is 600 miles (1,000KM). I change my oil and filter at 300 miles (500 KM). The coolant level in my overflow tank is currently at 1 1/2 inches (28-30 mm) up from the overflow inlet hose.

Disconnect the gray wire, if you have one. It remaps the ignition to the YZ engine advance curve and goes with the more complete throttle opening that you have with the YZ throttle stop, you will like it. BUT, I'm not sure that you have a gray wire (I think so, but I wouldn't bet the farm on it). Make sure that you check the connector that is found behind the left-side number plate where the CDI unit is located. It will be a 6-wire plug and one of those wires will be gray. Just push the wire out of the harness and tape it with electrical tape. DO NOT cut or disconnect any wires located near the steering head/ front forks. The gray wire was located in this area on the 2003-2006 WR450F's. It has been moved to behind the left-side number plate on the 2007-2008 WR's.

Some have had good luck leaving the stock jetting in the bike. Others found this to be too lean. I looked up your jetting on the Yamaha-Europe website. I appears that your European spec bike is jetted the same as the American model WR450F. I jetted my 2008 to the jetting specs for the 2004 WR450F. This was the last year that the bike was produced before Yamaha added the smog equipment and leaned out the bike for cleaner emissions. If you look at the American WR450F carburetion specs for the 2004 and 2008 WR's the only difference is the Main Jet size and the Needle size. The 2004 was #165 Main Jet and OBDWR Needle 4th clip position and the 2008 is #162 Main Jet and NFNT non-adjustable Needle. I ran the 2004 jetting in my 2006 WR450F, which had the emissions equipment and lean jetting stock from Yamaha and I was very happy with the bike's performance. You will get lots of different opinions on the jetting issue.

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  • S1rst

Posted October 06, 2008 - 04:05 PM


Thank you both for that. :lame:

bajafool, thats brilliant thanks mate, youve answered all i need to know. Ill have a look for the grey wire to check it and do what you said if its still connected. Ill also top up the coolant tank so the level is actually visible.

I phoned my dealer about oil and they actually mentioned yamalube but thought id check on here with people that actually know as i dont trust bike/car dealers that much when it comes to advice and knowledge. I think ill go with the yamalube then and do a few changes at early intervals and check the state of the oil and take it from there.

Thanks, Rich. :bonk:

  • MPHorvat

Posted October 07, 2008 - 07:41 AM


Its had the baffle and restrictor removed from the exhaust and the throttle stop screw taken off

This has been a semi-contentious issue. Many people have stated that it is better to have a proper-YZ-length throttle stop screw in there, than to have it removed completely. The propoents of this approach state that without any throttle stop screw, the slide can move up too far, get cocked, and then stick up there, leaving you WFO, potentially amongst trees, sub-optimal.

I would recommend either a YZ throttle stop, or the stock WR throttle stop trimmed to the YZ length.


  • BajaFool

Posted October 07, 2008 - 09:32 AM


MPHorvat makes an important point. When you say the throttle stop has been removed, do you mean that it is no longer in the carb, or do you mean that the excess material has been removed from the WR stop to make it the same length as the YZ stop?

It is important to have a throttle stop in the carb. Without the throttle stop, the engine can lock in a wide-open condition and serious damage to your body and motorcycle may result. If the throttle stop is not installed in the carb, install a YZ throttle stop. If you have the old WR throttle stop, cut the stop to a total length (from one end to the other) of 23.4mm from the original length of 35.7mm, round off the end of the stop the same way that the original stop was rounded.

  • S1rst

Posted October 07, 2008 - 02:21 PM


Thanks for the heads up on this throttle screw! Ill have to check that to make sure the YZ one has been put in. I have the black screw in the spares box, so i hope there is a YZ one in there as i havnt actually checked this myself. Ill check in the morning.

Thanks. :lame:


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