i did a search but came back blank, so here goes. i have the 400ex which oil and weight should i be useing?? how many qt's does it take?? and brand of oil??. and how often should it be changed i here some claim to change it after every use and or like 10 hours, that seams like over kill??.
thanks again

 

after looking around i did find some of what i'm looking for. looks like 10w-40 will work ok. but still could use the rest info.

 

weight of the oil depends where you ride. depending on weather, like temperature, will affect which weight oil you should use.

 

i think 10w-40 should work for wi.summers, any idea on how often to change?? or # of qt's??

 

I'm using the same oil for two months now. Still haven't changed it yet.. Maybe I'll change it soon.

 

good oil = engine life

 

i run 20w50 summer 10w40 winter.400ex is a old school motor they can handle thicker oils.a lot of people run 15w50 in summer.it is pretty much up to you.what kind no cheap crap use something that is certified for 4 stroke atv,s

 

i have a 250 ex and if uses 1.7 quarts.... i know if you look it up on yahoo you can find it but i changed mine for the first 10 hours because it needs to be broken in. other than that the book says every 20 i believe.. also since its summer you can run a thicker oil but it all depends to you. ask your local dealer

 

It holds 1.95 qts, I believe, but you never get all of the old oil out when changing it, so a little less than that will go back in. Drain the tank, then the crankcase, add about 1 3/4 qts, start and let run until warm, check it and top it off.

If it's new and being broke in, stick with Honda GN4 10w40, after that you're free to use whatever you want, provided it's not a synthetic with moly(which will cause the clutch to slip). Most of the guys I've talked to run either Rotella or Mobil 1, 15x50 in the summer and either 5w30 or 10w40 in the winter, depending on how cold it gets where you are at.

 

Maxima Extra 10W-40 pricey but good stuff.