2003 yz450f. Questions

What is the best oil to use and after fully drained how much should i put in?

I mostly ride mx and trails is the stock gearing allright i havnt got to ride it yet until i get my new subframe soo i need to figure out or get some opinions on some mods.

Help appreciated.


This is a huge topic which has been beaten to death. I'm sure if you searched for "good oil" you'd find pages and pages of info.

As for me, I like to use Motul 5100 Ester semi-synthetic. Bloody good stuff and at $30us for 4 litres its great value compared to the fully synthetic stuff. Everyone has their own opinion, but I don't think it's worth wasting money on a fully synthetic as long as you change your oil all the time (once every 3-4 rides).

Can't help you with the oil capacity though. However I think its about 1.4L

thanx for the information. After you drain the oil do you just put it through the place on the top of the frame and let it feel up to the dipstick? what radiator fluid would you recomend? Also when i took the oilfilter cover off there was no oilfilter in there it really worried me on the past of the pike but all the bolts were loose around it. i have started it and it runs great and it dont get hot or make no noises everything seemed to be okay. from reading post on here i think i am going to get a aftermarket flywheel because of stalling problems and etheir a white brohters carbon pro or a dr.dubach. Also doesy anyone got any stock parts forsale subframe,plasitc,shift levers. if so pm me.

Thanks, Friday Adkins

I would suggest you get a manual immediatly!First off put a filter in your bike.You put the oil in the engine,not the little hole in the frame.You must start it then shut it off to check your oil.It holds a little more than a quart.Also that cover over your oil filter must have a good seal(tight and no missing or torn o rings)because if i am not mistaken,if it is not sealed you wont get any oil to the top end of your motor.

No problem. I also agree with bigc, you must get a manual ASAP! Before any pipe/flywheel weight or other aftermarket part. Once you've done the oil change, start it and loosen the oil gallery bolt. If oil flows out around the bolt in less than one minute all is good and the top end is getting oil, if not shut the bike down and check everything over. If you look at the right hand side of the bike you'll see an oil line running up the side of the cylinder. The oil gallery bolt is the one connecting the top of that line to the cylinder. Also be careful when doing it up as it is hollow and very very easy to shear.

1000 CC'S at oil change

1100 CC'S at oil change w/ filter

hey, Thanks for all that information that helped alot. This is my first yamaha so im trying to figure out how all the little things work so i can keep up on the bike.

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