GPR Stabilizer, Radiator & more!

GPR Stabilizer, Radiator & more!

Winter has hit here in the Midwest.. so you know what that means! Christmas Farkles!!!  For years I’ve wanted a stabilizer for my WR250R but never pull the trigger on one. Well this year I couldn’t pass the $100 bucks off that GPR was offering so I went for it… if you’ve never put a stabilizer on, now you can see what’s involved. Here’s where you can get one: GPR V4 Stabilizer. I also decided to replace my sparkplug and flush the radiator! Let’s do this…

First Things First!

Before I could bare to work in the garage I needed a little heat…. aahh much better!

Now it’s time to take the front end apart. I ended up taking the front tire off and slide the forks below the top triple clamps. Remove your top clamp and handlebars to expose the stem nut. I tethered my bars up out of the way with a nylon strap…

Here you can see I removed the lower clamps before removing the top triple clamp.. you DO NOT need to do this. Just take that top triple clamp off… then take the lower clamps off.

You’ll need to remove the gas tank too.. so this can be done before or after the top triple clamp is removed.

Secure the tank out of the way with a bungee.. works for me!

Remove the stem nut with a 27mm socket…

Here she is all ready for her new stabilizer… be sure not to pull in the front brake with the wheel off, or you may find yourself bleeding the brakes!

Time to get Stable!

Open up the stabilizer package but be careful as there are some loose parts, always layout your parts carefully, not to loose anything. Now that the top triple clamp is off, place the stabilizer base bracket over the head tube. You’ll notice on the right side of the tube there is a notch that the base fits right into nicely.

Now.. NOTICE the two arrows in this photo below.. no where in the documentation was it mentioned that the clutch hold bracket would interfere with the base bracket. So you get to learn from me on this one…

A little early warning, when you get the top triple clamp, bars, etc. all back together and move the bars from center to left, this clutch hold bracket(blue arrow) will hit the stabilizer base where the red arrow is. When you move the bars from center to left it just feels like the stabilizer is grabbing because you can still move the bars to the left, but what is actually happening is the clutch hold bracket is being bent as you move the bars!! I had no clue this was hitting, it really felt as if the stabilizer was tightening up and when you moved back to center or all the way to the right it felt fine.

Here you can see the bracket bent and it quickly notched the stabilizer base…

So be warned!! To fix this I took a long flathead screw driver and bent the bracket out of the way. All is good now! But do be careful and look at this to see if you can get the bracket bent out of the way prior to putting everything back together.


Right about now is when it hit me…… In order to change the spark plug with everything back together, yes, the stabilizer is now in the way! Luckily, you can remove the stabilizer pin mount to get the tank off… It’ll be a bit more tricky now…but well worth it!

Speaking of spark plug, I haven’t replaced mine EVER! And I’m at 15,871 miles.. guess it’s time… To get the ignition coil off of the spark plug it took a bit of tugging.. it feels as if you are going to break the thing. I took a pair of channel-locks, grabbed it lightly and pulled it off the plug…

Before removing the plug, take your air compressor and blow any debri out of the plug cylinder.. there she is..

And boy did it need to be replaced!!!! Replacement Plug: NGK CR9EK

Radiator Flush

So while we got this thing all apart, why not flush the radiator and give it a fresh fill of fluid! So that’s what I did. First you’ll need a few things: Vinegar, Distilled Water, and some motorcycle coolant. The coolant I use is Cycle Logic’s Engine Ice.

Here’s a good video from CanyonChaser’s on the basic steps of flushing your motorcycle radiator, I’ll note a few things below.

For the WR250R, you’ll do basically the same steps as the video shows, make sure you catch all of that old radiator fluid. I used a paper plate as a funnel into a small bucket. Loosening the radiator cap(you’ll need a M3 hex key), but don’t remove it completely, then loosen the drain bolt…

Don’t forget the overflow reservoir, you’ll need to remove two hex bolts and pull the drain tube down in order to remove the reservoir…here you can see the drain tube pulled out of the way…

Once the reservoir is removed, fill it with half distilled water and half vinegar. Shake that thing up good, and rinse.  I did this a few times. I connected the reservoir back up but DO NOT mount it…

Next, fill the radiator and reservoir with the half vinegar/half distilled water mixture and get the engine up to temp. Then drain it and repeat two or three times. After your last drain, you’ll want to disconnect the reservoir and drain it completely. You can use distilled water if you need to flush it a bit more. Now you can bolt it back to the bike and fill to the correct levels per your service manual with Engine Ice.

I feel so much better now.. new plug and new coolant! On my bike with the Safari tank the radiator cap needs to go on like so.. or else I can not get to the lock bolt.

Now back to the stabilizer install… This little bracket marked by the arrow, I threw out, it was just adding too much weight!

Place your tank back on the bike and bolt it down. You’ll see the tank bolt also holds the stabilizer base. Using a 5mm hex key, tighten the stabilizer base to secure it to the frame…

Set the stabilizer lower bar clamp on the top triple clamp and bolt ‘er down good!

Tighten down the top triple clamp to the stem bolt using the PROVIDED GPR NUT, do NOT use your stock nut or the stabilizer will not fit at all.

Attach and tighten the pin mount bracket, you can now see that it covers the tank bolt… next I’ll show you the proper adjustment of the pin…

Set your GPR stabilizer unit on the lower clamp and tighten. I added some blue Loc-tite as well… below you can see the pin sticking above the stabilizer arm.. this is wrong, and will void your warranty?!?!

Taking a punch tool or small driver, tap the pin down slightly and easily.. so it aligns with the arm perfectly…

There we go! You can now put your bike back together.. make sure you tighten everything correctly.  You will see on the stabilizer setting #1 is the SOFTEST setting, for light riding, no dampening at all. Setting #8 is the HARDEST setting for long, straightaways.. and sand!  What I love about the GPR is you do not have to go from #8 back down to one, turning the knob in reverse. Just simply continue to turn and it will reset automatically back to #1! That’s cool!  Settings #2 through #7 are for fine tuning, depending on what terrain you are riding on, dial it in and say good by to arm pump!

GPR V4 Stabilizer Install Directions – pretty limited in info but here’s their PDF.

One issue I had is my custom Highway Dirt Bikes top clamp has a powerlet and heated grips switch… the wiring now interfered with the stabilizer…

Electrical Time

So to fix this issue, I’ve replaced the standard Powerlet socket with a low-profile Powerlet socket.

The wire connectors that come with the low-profile Powerlet are useless in my opinion… these things..booo!

Not very weather resistant for an Adventure bike..

I’m replacing these connectors with Eastern Beaver’s Sumitomo MT Sealed Connectors. Jim at Eastern Beaver has great motorcycle electrical products, he’s always been very gracious in answering any questions I’ve ever had.. thanks Jim!

Notice in the photo above, I setup the connector exactly how you put it together.  Installation is pretty straightforward, the hardest part is crimping. I don’t have one of those $70 crimpers so, I had to make do! Strip your wires then tin them up.

Next, crimp on the connector, you do not need to solder these if your crimp is good. Just be careful if you do solder not to get excess in the connector slots.

Slide the connector ends on and snap it all together.. bam!

No, for the heated grips rocker switch, I’ll be adding 90 degree connectors and cleaning up the wiring.

In all it’s glory! Can’t wait to get a rip on this thing now…

The GPR Stabilizer’s adjustment knobs are incredible, very easy to adjust while riding. This is one feature I really liked over other stabilizers out there. Stay tuned for a review after I get a few rides in… come on warm weather!

  • Buck Greene
    Posted at 14:29h, 01 October Reply

    Hi Bill,

    Once again, your website and step-by-step instructions are a tremendous grace to those of us who ride the same bike as you–thank you!

    Am I correct in understanding that the combination of the GPR stabilizer, your HDB top clamp/riser set-up, and your Pro Taper EVO Harry Reed bars all work together without having to lengthen any of your control cables?

    Thanks again!

    • Basher
      Posted at 08:48h, 13 October Reply

      Buck, That is correct, I did not have to lengthen any of my cables and it has worked out very well!! Thanks for the support, Ride Safe!

  • Buck Greene
    Posted at 08:09h, 30 October Reply

    Hello again, Bill!…how about a review/ride report on the GPR Stabilizer? Would love to hear how it changed/improved the WR’s steering/handling.


    Buck Greene

    • Basher
      Posted at 09:31h, 30 October Reply

      Hey Buck.. !

      Sure thing.. that sounds like a great post.. sorry for the delay in posts.. I’ve been busy riding! 🙂

      Ride Safe,

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