Oversize aluminum oil tank and air box

[MtnEX]

I got some good riding in on sunday, and I ran into another 400EX owner out in the trails... also new to his 400EX.

Of course we were checking out each other's mods... but he really couldn't tell me anything about his because the previous owner did them all.

He had a nice big aftermarket oil tank on his. It looked like it might hold a lot more oil, which I'm thinking might be a good thing?... And also had more surface area for cooling. He couldn't tell me how much oil it held because he hadn't even changed the oil yet.

Heck, I'd almost buy one just for the better looks of it... if I knew for sure it would fit with my head pipe... and if I could find out who makes them.



Also, the guy had an aluminum airbox. It relocated the battery, wiring, etc to inside the airbox. The battery fit in the back of the airbox and the wiring mounted on the inside wall. The snorkels and stuff were also gone.

I did not like the way it crimped the intake hose to the carb, and it did not have a lid, so it was much dirtier in there than inside mine..... BUT I DO GOTTA ADMIT IT PROVIDES SUCH A CLEAN CUSTOM LOOK.


Has anyone done these custom mods that can tell me more about them?

[hypersnyper6947]

I was looking into the oversized oil tank to help keep my 440 cool. Does anybody know if it does help with the temp, also how much extra oil does it hold?

I have the air box you described. The guy who had it before me put it on as well. The wiring looks a bit messy other than that i like it. It fits my k&n and battery quite nicely.

[Wildbrain]

I have the larger oil tank on my 440. I think it's made by PRM. It holds almost 1 additional qt of oil even though they say only about an extra 1/2 qt.
I feel it really helps with cooling down the oil cause I have never had any overheating issues.
It also helps to run race gas,110 octane, to keep things cool also.
It will fit in there even with oversized headpipe. Not by much but it will fit.

[MtnEX]

I don't see it listed at PRM anymore... hum....?

[Wildbrain]

Sorry.... Its a UM tank.
http://www.magicracing.com/UM-Oil-Tank--TRX400EX_p_169-660.html

[NacsMXer]

IMO you would be better off with either putting a SPAL fan on your stock oil cooler, or get a larger oil cooler. I run a cooler that is about 2.5x as thick and about 3x larger overall than the stock cooler and it REALLY helps to keep the temps at bay. I bought it from Desert Toyz ATV as a kit complete with custom oil lines, but I don't know if they still make it. The cooler itself is readily available as a universal transmission cooler as far as I know.

The oversized oil tanks are marginally worth the cost. Extra oil is good, but how much will that benefit the motor in terms of running cooler?

Think about this analogy... You have 2 quarts of water in a pot you are wanting to boil on the stove. Next to that you have another pot with 3 quarts of water you want to boil. You begin to heat both pots at the same time until they start to boil.

Once these two pots of water are boiling, they are boiling. The only difference is the slight bit of extra time to heat the 3 quarts of water vs. the 2 quarts of water. The point is, once your oil in your motor reaches operating temp, it's nice and hot. Adding extra oil capacity will just take it a little longer to get to operating temp, but once it gets there it's just the same temperature as it already would be. The only difference is extra hot oil going around.

What WILL make a difference in cooling is the actual cooling system for the oil....i.e. putting a fan on the stock cooler, installing a bigger oil cooler, or both. Many on this site have also installed auxilary oil coolers in tandem with the stock cooler with good results.

As far as the aluminum airboxes go, they are definitely a nice upgrade over the stock plastic unit. I have been running a UM aluminum airbox for years. I like how it keeps the battery out of the path of water/debris as well as keeping the mass of the battery centered on the quad. The one I run has an open lid only since that is the best route for performance but there are other aluminum boxes on the market that incorporate lids with water-resistant Outerwears lining the opening.

[mooseracerX]

I have an Insane Performance airbox. I really like it too. Cheaper than the UM too but the quality is really good.

I think the bigger oil cooler would be good but it will cost more. I think the UM is like 3 quarts to fill it up or something so you shouldnt ever have to worry about being low on oil because theres so much more oil. Ever see the oil coolers with the airflow holes through them? They have holes right through them so air can pass through the holes and theres even more surface area to cool. You do run cooler with more oil but how much I would love to know. I like the idea but more oil for oil changes i'm not crazy about.