How To Change the Coolant in Your SV650

Humble engine coolant: killer of dogs, savior of overheated engines. And, on your SV650, something that needs to be changed every 2 years or so.

This guide is written for those who are new to working on their motorcycles. As such, it’s written at an exhaustive level of detail.

In this guide, we’ll change the engine coolant on a 2007 SV650. These instructions should work for all second gen (2003+) models of SV650, though if you own an S or SF model, you’ll need to figure out how to remove some plastic on your own. For the final word, consult the service manual for your bike.

Step 1: Gather the Required Tools and Materials

Tools

• small phillips head screwdriver
• pliers
• 10mm wrench or socket
• hex (allen) bits or wrenches: 4mm and 6mm
• drain pan
• measuring cup
• clean funnel

Consumables

• antifreeze (at least 1 US qt)
• distilled water (at least 1 gallon)

A Note Regarding the Selection of Antifreeze

“What antifreeze should I use?” is a common question. Here’s the word straight from the service manual:

Use a high quality ethylene glycol base antifreeze, mixed with distilled water. Do not mix an alcohol base antifreeze and different brands of antifreeze. Do not use a radiator anti-leak additive.

During this particular coolant change, I used Prestone Extended Life Antifreeze. It’s an ethylene glycol based antifreeze and also silicate free. If you’d prefer a motorcycle-specific coolant, I recommend Pro Honda HP Coolant 50/50 Blend. Note that the “50/50″ in the title refers to the fact that it’s already pre-mixed with water, so don’t go adding more water if you buy this coolant.

Step 2: Drain and Flush the Radiator

This maintenance should only be performed on a cold engine!

First, locate the radiator cap. (If you have an S or SF model, you’ll need to remove the cowling before you can get to the cap.)

Loosen the radiator cap stop screw.

Remove the radiator cap by pressing down on it and turning counterclockwise, like removing the cap from a child-proof pill bottle. This opening is the radiator inlet.

Locate the coolant drain bolt.

Put some cardboard or newspaper down below the bike and situate your drain pan so that it’s underneath the drain bolt. If you’ve got rubber gloves, now’s the time to put them on. Use the 10mm wrench on the bolt. I recommend turning the wrench so that the bolt just begins to move. Then, slowly loosen the drain bolt by hand. The old coolant will trickle out the hole and down the side of the bike. It’s a messy job, but the alternative is to loosen the drain plug completely while a 12 inch long stream of coolant shoots out the side of the bike.

Once the coolant has drained down to a trickle, flush the radiator by slowly pouring distilled water into the radiator inlet. Keep pouring the distilled water into the radiator until it runs clear out the water drain hole.

Let the water drain completely. If you want, you can sit on the bike and slowly rock it from side to side to help hasten the process. Once the water has drained, replace the drain bolt and re-tighten. Torque specs: 13 N·m (1.3 kgf-m, 9.5 lb-ft).

Step 3: Drain and Flush the Reserve Tank

You’ll need to lift the gas tank in order to reach the cap on the reserve coolant tank, and to do that, you’ll also need to remove the seat. Use the 4mm hex (allen) bit to loosen the 2 bolts on the plastic trim covers below the seat. There’s a cover on each side of the bike. Remove both covers and set them aside.

Then, use the same 4mm bit to loosen the 2 tank bolts. I like to use a T handle bit driver to reach these bolts.

Whatever you do, don’t drop your bit around this part of the bike! It could very well end up in some impossible nook or cranny.

Next, use the 6mm hex bit to loosen the 2 bolts holding down the seat. There’s one on each side of the bike.

Once the seat is loose, lift it up by the edge closest to the gas tank, then pull the seat forward until it slides free. Remove the passenger seat and grab the gas tank prop. Use it to prop the gas tank up by one of the tank bolt holes.

Now you’re ready to drain the reserve tank. Locate the cap on the left side of the bike.

Pull the cap out and set it aside. Next, go to the right side of the bike and locate the reserve tank hose where it meets the radiator inlet.

Use the pliers to squeeze the clip tabs together and slowly twist the clip while pushing it back up the hose. You’ll feel it when it passes the bump on the metal tube that holds it in place.

Make sure the drain pan is underneath, then push the hose down as straight as possible so it drains into the pan.

Again, you can rock the bike slowly from side to side to hasten the process. Once the coolant slows to a trickle, flush the reserve tank by slowly pouring distilled water into it until it runs clear through the hose on the other side. Let the water completely drain, then reattach the hose to the radiator inlet and use the pliers to replace the clip. Put the reserve tank cap back on.

Step 4: Mix and Add Coolant

If your chosen coolant is not already premixed, you’ll need to mix it with distilled water. The instructions on the coolant bottle will tell you if you need to do this step or not. The proper ratio is shown by this chart from the service manual:

Antifreeze Density	Freezing Point
50%	-31° C (-24° F)
55%	-40° C (-40° F)
60%	-55° C (-67° F)

Select the density based on the lowest temperatures that your bike will be exposed to (this includes winter storage). Oregon rarely gets below freezing in the winter, so my ratio mix is 50% coolant and 50% distilled water. Make sure you’re using distilled and not purified water.

You’ll need to make approximately 1730 ml (1.8 US qt) of mixed coolant. Slowly pour the new coolant into the radiator via the radiator inlet until the coolant reaches the edge of the opening.

Step 5: Air Bleed the Cooling Circuit

Now we need to get any air we introduced to the system out of the cooling circuit. This is called “bleeding” the air out, and it can be a time consuming process. Here’s how to do it.

Sit on the bike — watch that exposed battery and propped up gas tank! — and slowly rock it from side to side. You’ll see the level of coolant in the radiator drop as the rocking motion causes air to escape. Top the radiator off with new coolant.

Next, start the engine and let it warm up to normal operating temperature. As the engine warms up, you’ll see bubbles of air at the radiator inlet. This is a good thing. I let the bike run until the thermometer on the display reads around 150° F. Shut the engine off and allow the engine to cool down.

You’ll notice that as the engine cools, the coolant level in the radiator will drop. Once the engine is cool, top the radiator off again with new coolant. If you want to be extra careful, repeat this warm-up/cool-down/top-up process a couple of times.

Replace the radiator cap by matching the tabs in the cap with the slots in the inlet port. Push down, then tighten the cap until it’s secure. Then, replace the stop screw on the cap.

Step 6: Fill the Reserve Tank

Remove the reserve tank cap and pour in the new coolant to the full (F) mark. Replace the cap.

Remove the gas tank prop and lower the gas tank. Replace the 2 bolts at the front of the gas tank. Put the seat back on and replace the 2 seat bolts. Push the side trim covers back into place and replace the 2 side cover bolts. At this point, everything should be back together again.

Go and take a nice ride, stopping after the first few miles to check the coolant level in the reserve tank and look for any leaks. If everything checks out, you’re done. Feel free to scoot back home and enjoy a frosty beverage.