XR650L: Spud's Oil Cooler

For a while I have been considering different options to install an inexpensive, well-protected oil cooler for my XR650L. I finally decided to experiment with one of the Long/Tru Cool, power steering coolers sold by Baker Precision.

http://www.bakerprecision.com/trucool.htm

Because I wished to keep the oil lines feeding the cooler well protected, and as short as possible, I decided to purchase the 4”x4”x3/4”, small, power steering cooler, which sells for $29.95. After considering a side mount, I finally decided to mount the oil cooler on the bike’s downtube, as high as possible, directly behind the front fender.

I constructed a frame for the oil cooler from 3/4”x3/4”, aluminum angle stock, and 3/4”, aluminum bar stock I purchased from Home Depot. I bolted the oil cooler to the angle stock, and completed the cooler’s frame by bolting two cross pieces of 3/4” bar stock.

I mounted the bottom of the cooler to the frame with two, 1/4”x2” bolts, and a short piece of aluminum behind the downtube. I attached the top of the oil cooler to the frame with a plastic zip tie, which I intend to replace with a steel cable tie.





I purchased SAE J1019, transmission oil hose from a local CarQuest store. I ordered five, 90-degree, brass hose barbs from a local hose supply shop. Since I wanted to install a Trail Tech, TTO Temperature Gauge, I also bought some brass fittings from Fastenal. Most of these fittings are also available at many auto supply stores.

I cut the external oil pipe just above the rubber grommet on the frame, and plumbed the oil line into the bottom of my oil cooler as shown in the photographs below. I plumbed the top line from the oil cooler into the line feeding the oil reservoir in the frame. I installed the temperature probe in the oil line between the engine and the oil cooler so I can get a continuous reading of the oil temperature as it exits the engine, before it enters the oil cooler. I secured the oil hoses to the bike’s frame using 5/8” loom clamps I bought from Home Depot. I drilled holes in the front fender, and shimmed the fender down with nylon spacers so it would clear the oil cooler.






























After installing my Spud Cooler, I went on a 110-mile ride to test it.













I’m pleased to report the oil cooler works well. I paid approximately $95 to purchase the parts needed to assemble the oil cooler. I spent an additional $50 to plumb the TTO temperature gauge into the oil line. I will continue to report on the effectiveness and durability of this oil cooler as I accumulate more miles riding my XR650L with the oil cooler installed.

Spud

Good job Spud!

John

Nicely done

Excellent work!!

+ another Spud

That looks great Spud! What kind of oil temperatures are you observing now under operating conditions?

damn goo job man!

I need to do something like this too...

is that temp reading you took right after shut down after or during the ride and what kind of riding was it?

cheers

Very nice!

Holy smokes Spud.....did ya buy stock in a hose clamp factory


Kiddin.........looks quite decent.........how are your clearances when the wheel is turned full left/right........and hows the clearance for the fender and wheel at full compression??????????????

If that checks out it looks good to me...i still like Marks cooler though.........but this is definately cheaper.

Hey.i started a rebuild thread if you`re interested...read along,,,i have a few issues so far..but what doesn`t when you gut something completely apart........

Good job.....know how about a good stereo install.....i`d love to have tunes on my bike going through the woods


B

damn a little harsh but I understand your point

I have a question for you

has anybody done or know whats prefferable, airflow over the valve cover/topend OR lower oil temps with the introduction of an oil cooler?

I ask this cause I have done the fender mod like spud using BIGGER less count holes and thought a liitle more airflow is better than not,

I do not have an oil cooler installed though but want to

If anybody has proof or data that will back up this question Id appreciate this

I think this cooler is a great project well made and a lot of thought put into it, yes it needs a little trimming on the tubes and such as I too think its a little much but I think your last sentence was uncalled for...

anyways

to all a happy sunday

christian

Well.........if you vent the back of the fender you get more airflow to the head....that`s a good thing in hot weather......but if you ride in alot of mud then venting the fender causes it`s own issues of caking mud on the fins/head which is really not good.........

A big fin head would probably be the best bet....fins are out farther,catches more air,,venting the fender probably wouldn`t be needed then...depends on how/where you ride i guess...

I know for me,the oil cooler definately stopped the oil from turning charcoal black in 500 miles...that in itself has to be a good thing..

B

Hey Spud,

Once again, you show your resourcefulness, and ability to keep us all in awe. Very good work.

I have two questions.

First, what problems (overheating) did you encounter that led you to add an oil cooler? I am guessing that the high Idaho desert in the summertime causes problems, but what were they?

The second question regards the placement of the new oil cooler, and access to the spark plug. I don't know about you, but I can barely get my hand in there right now--have you tried to remove the plug since you installed the cooler?

PD

yeah I vented my fender taking into account that I almost never ride in mud unless I have to...

If I do for some reason I thought about adding screen mesh to the backside and glue it on

my fender is also shorter in the back than stock, its a modded crf250 fender I think

anyways

I wish I could find a tranny oil cooler like spuds that I could mount where the xr250 and xr400 coolers mount as that would be the best, protection wise and airflow wise

someday someday

again spud congrats hope the cooler lasts and it looks like it works well so far...maybe just add a littel protection to the pipes and hoses so they dont get snagged?

cheers

Thank you for the kind words, John, Grover, TJ, and BigMan.

Spud

On my 110-mile test ride I traveled on the freeway, gravel roads, and paved, secondary roads. My engine oil temperatures were usually running 170-210 degrees, Fahrenheit. I rode at 75-80 mph for 26 miles on the interstate. At the end of that ride my engine oil reached a high temperature of 258 degrees. I backed off the throttle to 65 mph for the last 3 miles before my exit, and the oil temperature dropped to 250 degrees before I exited the freeway. Once off the freeway, the oil temperatures quickly returned to lower levels. If you turn off the engine, the oil temperature cools rapidly. If necessary, I plan to cut out the drilled portion of my front fender, and install aluminum hardware mesh to increase airflow to the oil cooler. However, I will wait for warmer weather to see if this is necessary.

Spud

Thank you Christian. That photograph was taken immediately after I returned home, and stopped the bike at the end of a long ride.

Spud

Thank you, XRider.

Spud

You are correct about potential problems with full fork compression, and I'm glad you mentioned this. While designing this oil cooler I realized the front wheel would strike the oil cooler with full compression of the forks. However, I don't ride hard enough to fully compress the forks on my XR650L, so I reckoned this scenario would not be a problem for me. If I were going to jump the motorcycle, et cetera, I would not have installed my oil cooler in this location.

My oil cooler installation is quite solid, and doesn't rattle. However, the installation does have enough flexibility to absorb vibration from riding. The 3/8-inch elbows have 4 hose barbs on each end, so I am confident they will not leak. I seem to be getting sufficient airflow from my drilled fender. However, I plan to cut a window in the fender, and install wire mesh if it is necessary to increase airflow.

I'm still experimenting with this installation, so I appreciate all constructive input. If I encounter any problems with my current configuration of this oil cooler, I will be certainly report them.

Spud

I can't fool you, Brian! I invested in hose clamp stock just before I started this project.

I mounted the oil cooler as high as possible while still maintaining good clearance with the forks when turned to full lock at both left, and right positions. Here are a few photographs to show the full lock, fork positions.















I don't doubt the wheel would contact the oil cooler with full fork compression. However, I don't ride the bike hard enough for that scenario to concern me. If I jumped the bike, or even came close to using full fork compression, I would not have mounted my oil cooler in this location.

I haven't measured for clearance of the oil cooler with full fork compression. However, the doctored photograph below simulates the amount of fork travel available before the wheel impacts the oil cooler. Incidentally, my front fender is now in a different position than the one shown in the photograph.



If I pushed my "piggie" this hard, I certainly wouldn't consider mounting my oil cooler in its present location. However, I plan to ride my KDX220 in the nastier terrain, so I wanted to install an oil cooler for sustained, high engine rpms while riding on the freeway. I am confident I have enough fork travel available for the off road riding I have now reserved for my XR650L.

During the design process for this oil cooler I conferred with my friend Andy, who is an experienced trail rider, and an experienced mechanic of 30 years. I have ridden with him a lot, and he doesn't think I will ever hit the oil cooler with my front wheel. He is also convinced this design is durable, and will not fail me. However, only time will tell. I will be sure to report any problems I encounter with this design.

P.S. Thank you for the kind words. I will certainly check out your rebuild thread!

Spud

It's easy to see if it will hit. Pull the top caps off the forks and push the wheel up. I am not convinced that it will hit.