What oil should I run in a 400ex in the summer? Any help would be appreciated.
tfh

 

Are you asking what brand or what weight?

Start with the temperature chart in your owners manual. In the frozen north I would run 5W30 in winter and 10W40 in summer. In the warmer south, I would run 10W40 in winter and 20W50 in summer.

Do a search. There are lots of "oil" posts here in the forum, and almost every person has a different opinion. The one common thread is to run a motorcycle specific oil that is API SG/JASO MA. I have posted lots of links to references where you can educate yourself in oil chemistry. By no means are all oils created equal!

My personal preference is an ester synthetic, like Maxima Extra or Ultra.

 

Thank you sir.

 

10w-40 i run it all the time no problems it just warms up quicker in the winter and in the summer its fine also 20w-50 is really thick dont you think?

this is just my oppinion hope you can change my mind or is there something i dont know about the 20w-50 thats special to use in the summer please tell i ming need 2 switch

 

Where I live, it is over 90 every day during the summer, and often over 100. (I do however make it a point not to ride during the hottest parts of the day.) But, if you go inland from here just a little ways, it is over 100 every day (and doesn't cool off much at night)......definitely 50 weight weather! Folks who live in places like Palm Springs, Las Vegas, or Phoenix, definitely need to run heavy summer oils.

As for there in Georgia, you need to decide just how nasty it really gets, and make a decision based on that. My grandparents lived in southern Tennessee, and I remember some nasty hot (and humid!) summers while visiting them!

Actually in summer I run Maxima Extra 15W50 in my autoclutch bikes, and Maxima Ultra 5W50 in my 400's and 450R.

 

10W40 Covers most applications above 15F. Be sure to use an oil that does not contain moly additives (friction modifiers) as the 400EX shares engine oil with the transmission. If you change the oil often, synthetics are not needed.