I recently got a 05 400ex and I have a few questions. How much air pressure should I be running in the tires? I just trail ride... nothing extreme.

Also what periodic maintenance needs done? So far I changed the oil/filter with mobil 1 15w50 synthetic and lubed the chain. Does the chain need tightened every once in a while?

Thanks in advance!

 

the change to synthetic might hurt the engin e if its got alot of hours on it.
Best to start with synthetic blend.

I have a 300ex, i run 4 or 5 lbs all around, i do alot of riding where i have
to slow down and crawl rocks, but this set up still does good when i tear it up
in a sand pit

check chain play, you only want an inch or so, if its looser,
loosen those rear swingarm tightener nuts, they are allen, u have 4 i think,
and take a big wrench and spin the tightener towards you, the chain will tighten.
you want 1 inch slack

 

Every quad/motorcycle has a plaque on it with recommended tire pressure. Also, it's in the owner's manual (4 lbs front and rear on my EX). But, those are for the stock tires, and if you have aftermarket tires you will need to experiment a little and see what you like best. 4 lbs is a good place to start, however.

Valve adjustments are very important! Should be done at 20 hours (right after break-in), then every 200 hours after that (I personally think 200 hrs is way to long!). If it is new to you and the previous owner can't doccument that it has been done, by all means get it done immediately!

Good articles about oil for your quad: http://www.thumperfaq.com/oil.htm

http://www.sportrider.com/tech/146_0308_oil/index.html

Whatever oil you pick, it should be API SG/JASO MA. If that Mobil 1 is "car" oil, replace it with some Mobil 1 Racing 4T motorcycle oil. Car oils don't contain the anti-wear additive package (ZDDP) that motorcycle transmissions need. There is a nice well doccumented post on another site (with pictures and all), of severe transmission gear pitting from a guy who ran Mobil 1 "car" oil in his motorcycle!!!

Mobil 1 is a PAO synthetic, which isn't as good as the ester synthetics. I run Redline or Maxima Ultra/Extra in everything. Motul and Klotz also have ester synthetic oils. All these are pricey, but so is Mobil 1.

Good read on the three different types of synthetic oils. For the record, Rotella is Group III, Mobil 1 and Amsoil are Group IV, and the esters are Group V:

http://www.maximausa.com/techn...news/LubeNews2002.pdf


http://www.p1-performance.com/pdf/oildoc.pdf

There is no problem switching to synthetic....that is just a myth! If anything, the synthetics have way more film strength than any petroleum oil or blend, and that should seal the rings on an older engine better.

 

http://www.atvriders.com/articles/oilchange400ex.html


http://www.atvriders.com/artic...veadjustment400ex.html

 

There was also a recall on the reverse spring or something like that on the 05's you can call a local dealer have them run the vin to see if it has been changed or not. If not your bike can suddenly go into reverse while riding at any speed or gear.

 

No , it is NOT a myth

My Neighbor gets paid big $$ he is an industrial lubrication specialist.
hows about that for a job title.

He does the lubrication for all kinds of giant industrial machines, down to a science.

He has taught me many things..

Engines develop clearances over time, carbon builds up
on the cylander walls, and the engine becomes set in its ways.
The gaskets and seals are conditioned to the type of oil that has been in there,
as well as to the pressures created by it.

So you throw sythetic in, You mess everything up.

you eat the carbon off the walls, change clearances, swell gaskets / seals
create nasty by products by mixing the old sludge thats stuck in the engine
with the synth. you will start burning more oil, maybe even leaking it depending on your seals, acid or other nasty compounds will start eating things up..

If you have a fresh motor GO FOR IT
if you have an older motor, you should use a blend first.
but what you really should do, is rebuild it with new gaskets and seals,
and than start using synthetic.

Yes, these are quads and not multi million dollar machines,
but the same principles apply.

Honestly dude, get that mobil out of there quick..
flush her out with some HONDA oil, or maxima, , and then refill her
on what you flushed it out with, change filters both times.

Shes an 05, i dont know how many hours are on it,
but you might be ok.. id still start with a blend, and def use a motorcycle
type oil

 

There is a good article out on the net about the history of synthetic oils. I will post it if I can still find it.

Synthetics did have some problems when they first came out, but these were all solved a generation ago. The trouble is, these stories have all taken on a life of their own, and everybody has bought into them like they are gospel!

Get yourself some Maxima Extra, or Ultra if you are looking for a performance oil, and change your oil fairly often!

 

I didn't get a manual with it. I've been finding most info on the net so far. I plan on getting a factory repair manual soon.

The oil I used was mobil 1 extended performance 15w50. On the sae label on the back it has only api service sm/cf.

I have no idea how many hours it has on it. It is in pretty good shape though so I'm guessing low to average hours.

 

I would not run that oil! It doesn't have the necessary additive package for a motorcycle engine/trans. Read about it here, from Mobil 1's own web site:

http://www.mobiloil.com/USA-En...le_Oil_FAQs.aspx#FAQs2

Your quad engine oil requirements are way different from a car. Your quad has an integrated transmission, that shares lubrication between the engine and transmission (a dumb idea IMO!). (Some Honda and KTM models now have the engine and transmission oils seperated...God bless them!)

 

I'll vouch for reconranger's knowledge on oil. Whenever I have questions I ask him and my bike has been running and shifting flawlessly since I got it! Thanks recon.