oil cooler

Hi there. I would like to ask you if it is possible to fit an oil cooler, or an oil radiator. The purpose is not only to have extra cooling, but more to augment the total amount of oil. Do anyone have foto's, or a schematic, references or any of your thoughts on this matter. I think a little extra oil capacity is no waste of money, on a WR for supermoto use (mainly street use)

It is very do-able. Check here for oil coolers - their smallest may still be too big, but worth checking:


You also can find some power steering coolers that are smaller and will do the job. If you only want increased volume, consider a fuel injection-style fuel filter. They are strong and available in many sizes and shapes.

Last thought is to go to a motorcycle junkyard and find a small cooler off a street bike.

Good luck, and let us know!


My old bike is a 94 honda XR 250. They have an oil cooler bolted to the front of the steering neck.

I don't think it would be too hard to mount it to the WR--- I will check this weekend to see if there is enough room to mount it on the WR.

NEAT idea!!! :):D

Realistically, how much extra capacity would that give the bike? 1/2 a quart? I wouldn't mind having extra oil capacity for those longer rides (like five days in Moab!)

It is a great idea for long runs! Problem is where to mount one. I have seen them as small as 6" wide and 3" high but again you need to place it in a safe protected area. Any ideas? :)

How about on the left side of the steering head? The little black box is mounted on the right so... :)

I think that with some creative thinking you could find/make a small one that you could piggyback on one of the existing radiators. You would have to manufacture a guard for the whole thing though. Another thought would be to put an oil cooler in the existing radiators (like the trany oil coolers in a car radiator), you would have to find a good radiator repair shop though. It does sound like a good idea.

As soon as I read this I too was thinking about my old XR250's oil cooler. Probably could get one used on eBay. I don't see why it wouldn't work. The headlight would probably have to be repositioned or replaced using an XR-style headlight shroud. But other than that, why wouldn't it work? The trick would be connecting it into the system. It would take some creative welding/brazing to make it all connect up.

I think the best place is down low so you can tie in to the oil strainer and make a loop through the cooler. I just hate the thought of pumpin oil up high on the bike and adding load to the oil pump. :)

I think the best place is down low so you can tie in to the oil strainer and make a loop through the cooler. I just hate the thought of pumpin oil up high on the bike and adding load to the oil pump. :)

Yes ! Thats exactly what i am concerned of. And i have to say, all the yamaha dealers that i talked with on this behalf, not one of them had a clear vision on this matter... Motor shop Gent (a yam dealer in Belgium) is gona do some research, and will give me a phone call in a week. I remember seeing an oil cooler made from solid billet for a honda. It augmented the total oil capacity with 500 cc. But I never saw this for a yamaha. If anyone has an idea, or better, real life experience, please share.

Here are some m/c oil coolers that I found.

You could probably get them a lot cheaper from other sources.

oil cooler 1

oil cooler 2

oil coolers

I like # 2 and looks like it would be easy to mount it.

You could make your own custom oil tank/cooler. Harley's have been doing that for years. You could make it round or square out of heavy steel or aluminum and stick it in front of the skid plate just below the frame tank bolt. This would make it easy to hook up and remove. You could put a drain pug in it for easy oil changes. :)

I think the best place is down low so you can tie in to the oil strainer and make a loop through the cooler. I just hate the thought of pumpin oil up high on the bike and adding load to the oil pump. :)

I don't think there would be any additional load on the pump as long as it's not pumping any oil higher up on the bike than it already is. Putting it down low would be preferable, but how would we protect it??

any of you guys remember the 1982 YZ's? The radiator was under the front # plate. It was a goofy setup, and cooling was crummy. It also gave the bike a high center of gravity.

If the oil cooler was mounted above the front fender, maybe behind/under the headlight...??? :)

You could route the return line to the cooler, and the cooler back to the main frame downtube.

I don't know about the (high?) CG though... :D

Another consideration would be airflow. The volume will increase capacity regardless of location but without access to moving air the "cooler" part of it is questionable. If you can't find a suitable place with a breeze to mount it you might try to add a fan (maybe a small computer case fan?). But then the weight, wiring and mounts would start to get heavy and complicated :). It does sound like a good idea but the engineering would take some doing :D.

Xmen, I checked to see if the oil cooler from the XR 250 would fit it is shaped like a horse shoe when mounted to the bike (viewed from above).

The measurement on the inside of the cooler is approx. 2.75inches it was tricky to get an exact measurement with in still installed on the XR.

This would add maybe 2 cups of oil to the total amount;not sure if that would be enough for what you are doing.

Installation would be a little tircky---welding 2 threaded inserts to the steering head and adapting to the existing cooler lines on the WR.

I completely agree that air flow will increase the heat xfr across the heat exchanger (oil cooler) BUT the radiator will still dissipate heat, albeit not as efficiently, but it WILL xfr to ambient. As long as there is a delta T between oil temp and ambient temp, the cooler HAS to give up heat.


I am quite intrigued by this thread! :D

This is a great idea! I will buy an aftermarket product like this for my bike if it works, looks good, and it doesn’t get in the way of other stuff. 1100 cc is not enough. I have been told by Yamaha mechanics to change the oil every three rides or 200 miles. I hope some out there is listening.

I'm not concerned about cooling. I'm interested in the extra oil capacity. :)

I just looked up the oil cooler fiche for a 2001 XR400. The new parts for the whole assembly are over $300! But it is a nice oil cooler. Hopefully someone can come up with a used parts solution.

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