oh i forgot to put 10 before litres- it holds 10 litres of oil

so i guess the rpms do make a difference.......

just another question- just because a crf250r CAN rev to 13500.... who actually does it? i think you would start losing power at around 11500 rpm wouldnt you?

 

Some good oil facts: http://www.thumperfaq.com/oil.htm

Nice thing about the Honda 450R quad and 450/250/150 dirt bikes is that the engine and transmission oils are SEPERATE, just like a 2-stroke! While these engines experiences a lot of blow-by and need frequent oil changes, the seperate transmission oil does not....God Bless Honda!

The rest of you SHARE the same oil between your transmissions and engine.

 

You guys that are doing the frequent oil changes are wasting money. Try changing to a good oil such as AMSOIL and you will not be needing to change the oil that much.

emeraldisleatv "I change the oil in my crf 250r every 2 hrs racing. Think about it: 650 ml of oil to lubricate and engine that can hit 13500 revs! High performance engines need high maintence. I have heard of some racers who can destroy the oil in the 250f in about 20min, this was found by testing the oil. The quads prob wouldnt be revving as hard or as hig so you would get longer out of the oil. "

This is just crazy. If you use a good synthetic oil the oil isn't going to break down in a 2hr race.

http://www.amsoil.com/racing.aspx

Get the good stuff.

 

NOT TRUE Mike.....at least not for the machines with little skirtless pistons. This isn't your father's engine, so we all need to stop thinking like the old days! If you don't own one of these new generation engines, you don't need to be that diligent about oil changes. Old school and modern low tech engines with long skirt pistons, aren't going to have this problem.......

......the problem is blow by contamination of the oil with fuel will dilute any oil down very quickly, high quality synthetic or not. It isn't a mater of the oil "wearing out" in that short a time, it is a matter of having gasoline added to your oil! It just won't be able to maintain its viscosity. It's just some simple chemistry folks, and shouldn't be so difficult to understand......


http://forums.atvconnection.com/mess...did/518224.cfm

 

Yes the crf250r revs to 13500 RPM. It is useful, its what we call overrev. Sometimes it can be a waste of time and momentum to upshift so you just over rev. I know I do be hitting the limiter out of corners and the starts.

BTW changing oil every two hrs of MX racing isn't crazy. Think about it 2hrs of riding your hardest. For practices I let it go a lil longer and I change the trans oil every 2nd engine oil change and the valves have yet to move 50hrs later. As it was said before these engines have short skirts and small quatity of oil. With the new 4storke race machines they need high maintence. Some serious guys drop the oil between races thats like 20min.

And a car would be totally different. Your not always pinning it in a car and they are not as high tuned engines.

 

BTW the 13500 RPM is for the 06 crf250r I think the redline was increased for the 07 not sure tho. But surely the new 450 sports quads are gettin up near there somewhere.

 

WTF????? 13500 isnt high enough yet? I just dont think its healthy to rev higher than 12000rpm with those kind of mufflers- they just sound like crap on the at 10000rpm with the low BRRAAAWWWP

and i doubt the 450's rev close to 13000 rpm because the yz450f produces peak torque at 6500rpm, so it may produce peak HP at around 10500rpm, but after that- you are losing a lot of power- and you are better off short shifting anyway at around 7000rpm, because you are at the fattest part of the poweband with 54nm torque on the yz450f

and arent most 450 quads modified from the dirtbikes to produce even MORE low end- so it would be even dumber to rev to 13000rpm

 

7,000 plus miles on my ds and only change the oil once a year, along with spark plugs and grease it up. No probles at all. Its been the best atv I have ever owned.

 

Wow, trail riding a big heavy DS650 in the Minnesota woods...has to be about as much fun as having dental work done! Still, way more fun that riding an 800 pound utility....that was manufactured in Minnesota.

 

Alot of highway miles riding back and forth to work. Thats when I worked at polaris, let me tell you my supervisors didnt like seeing a competitor quad out front. It actually isnt a bad trail quad you just have to pay a bit more attention when you are ridin.