I love riding at the dunes but as we all know our little air cooled 400's can only run great till the heat sets in. Mine is a 426 11:1 with a cam and mild port job. It runs great for about 6 passes and gets warm then falls on it's face so...

I have seen the kits made for around 100 bucks. Great deal for some but I know it can be done a lot cheaper. For $31 and some change I went to the local autoparts store and ordered the smallest tranny/oil cooler I could get. It comes with hose and clamps and the black zip binders for mounting the cooler. This one measures 12"x5.5"x.75". It has 3/8" fittings but used 5/16" hose and you'll see why.

The mounts were the tricky part BUT simple. The upper mount is made with three strips of aluminum, two are bent to a roughly 70 degree angle for the horizontal strip to rivet across where the cooler will mount. They bolt directly to the frame where the two black wire harness clips clip into. Remove them and they expose roughly 1/4" holes to bolt the upper mount to. The bottom is another strip bent to contour the cooler and bolted to the cross piece behind the bumper. I opted to use a felt weather stripping between the mounts and cooler for vibration wear purposes. The kit comes with little foam squares that serve the same purpose.

Once the cooler is mounted, it's time to adapt the oil line system. I disconnected the factory oil line on the right side (oil pressure line from engine) and cut just before the first bend with a small pipe cutter specifically to keep metal chips/shavings out of the system and for a clean cut. Then you'll take the other piece cut off and cut this about 1/4th of the bend from the factory cooler mount. The mount is reinstalled upsidedown so that it bends upward. Because the diameter of these factory lines are smaller than 3/8", I used 5/16" hose that fits very snuggly over. From the engine to the cooler and from the cooler back to the factory cooler and tighten with hose clamps. I started it up and topped off the oil with about an extra 1/8th of a quart.

Thinking mount ideas...


Mounted with the aluminum bracket bolted to the clip holes in the shock cross frame.


Plumbed into the factory oil system. No drilling, taping or any other BS required.


Fit and finished!

 

Thats pretty cool and all when u need it but by adding the additional cooler that will make your oil take a good bit longer to warm up (thinning out) to where ur engine will idle good and run good. in the winter i would think that it would be fighting you to get started. You should think about installing bypass valves to where when u turn a valve your extra cooler wont be in the system at all. this would be cheap and easy if u think about it

 

should just get some air scoops

 

VERY clean and professional looking install, I may have to do that on my 440ex my son rides. The only thing I would add is a good screen to protect that cooler from rocks and sticks. Good job!!

 

I took it out to the dunes this weekend and had a great time. I couldn't believe the difference it made! Pass after pass it ran consistant without any sign of power drop! I was so stoked. It really made a huge difference in that because it now runs cooler, it has much more torque and power. It was so successfull that a fellow rider saw the difference so I will be installing the system on his when I can make more mounts. His actually overheated twice while racing so hopefully it will eliminate his problem.

As for protection, yes you can put a cover over it but I do 90 percent of my riding at the dunes. I didn't notice any longer time necessary for it to warm up. It is only 30 degrees in the morning here right now and it had warm oil flowing through within just a couple minutes so I don't think a by-pass would be needed. Because of the 3/8" tubing, there isn't much, if any restriction in the system anyway.

I'm working on ideas to put a kit together for those that are interested.

 

well thats good to know. Im runnin a 416 11:1 wiseco piston with oversize carb and aftermarket exhaust and havent noticed any over heating problems. But what simptoms do u get when it over heats, loss of power. Do you think that a stage2 carb would make enough difference for me to buy. and then maybe i should install another cooler?

 

well thats good to know. Im runnin a 416 11:1 wiseco piston with oversize carb and aftermarket exhaust and havent noticed any over heating problems. But what simptoms do u get when it over heats, loss of power. Do you think that a stage2 carb would make enough difference for me to buy. and then maybe i should install another cooler?

 

I have never actually overheated mine before. Compared to liquid cooled quads, after several passes racing, it will get a little slower with each passes. Usually if I beat a 450 the first three passes, I will start breaking even or start falling behind if I continue pushin it. So the only symptom is the power loss when it get hotter and hotter. When its cool, it will pull third gear in the dune hill climb and hold it. After 4 or 5 races, it can't keep the power up to hold third gear but with this cooler, I didn't notice that power drop. I have a 450 carb sitting on the bench that will be going on this week. The 426 bore leaves the cylinder wall much thinner resulting in more heat as well.

 

Do you think this would help a stock 400ex any? I usually go to the desert and dunes too, and sometimes the temps out there are in the 90's to low 100's. I notice my z400's fan running longer and more often, but don't ride the 400ex enough to notice any power loss.

 

<div class="FTQUOTE"><begin quote>Originally posted by: d33pt

Do you think this would help a stock 400ex any? I usually go to the desert and dunes too, and sometimes the temps out there are in the 90's to low 100's. I notice my z400's fan running longer and more often, but don't ride the 400ex enough to notice any power loss.</end quote></div>

Yes I would in fact I'm installing the kit on a stock (well slip-on pipe) 400 tomorrow for a kid that primarily rides his in the sand. I'm very curious to see if it eliminates his overheating issues and works as well as mine. It gets really warm here in the summer but we ususally don't ride anymore once it reaches high 90's.