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Some Tips on Changing the 2nd Gen Coolant


V7Goose

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I thought I'd post a few comments for those who have not been through this before. It is not hard as long as you have the proper tools. T-handle allen wrenches are almost mandatory for me - they make turning out the many socket head screws fast and easy. In addition, if you follow the manual (Method #1 below), you really want a set of long ball-end 3/8" drive allen wrenches for use with your ratchet.

 

If you follow the shop manual, the job is pretty straight forward, but you will have one frustrating surprise. I have detailed the full drain procedure first as Method #1, then two slightly modified procedures that some might prefer at the expense of not getting out quite as much of the old coolant.

 

The first steps apply to all three methods: You start by removing the seat, tank, both lower fairings and all three battery covers. Don't forget to remove that top center #3 Philips screw on the middle cover; it is kind of hidden! The cover slips out to the left fairly easily, but you do need to watch down in the middle for hoses and wire bundles that will hang up on the corners. Now you are ready to begin draining the fluid.

 

METHOD #1 - The Complete Drain:

 

  • The radiator drain bolt is obvious on the bottom left, and getting the overflow tank out is pretty easy too. It is only held on by one bolt and a couple of lugs in rubber grommets. Just use your fingers to push that plastic shield above it up so you can pull the filler neck forward and out to the right side. Some folks prefer to siphon out the overflow tank instead of removing it, but I don't know why; taking it out is MUCH easier than messing with a siphon hose! (But you don't have to remove the center or left side battery covers if you are not going to remove the tank.) Note: If you remove the radiator cap before you take out the radiator drain bolt, the coolant will drain VERY fast with quite a bit of splashing; you may want to let it drain mostly on it's own before you take that cap off!
  • Next you will want to pull the fake cylinder fins off and take out the rubber plugs; use an old spark plug to screw into the plug and pull it out. Each cylinder water jacket holds quite a bit of coolant - seemed like about 1/2 cup each but could have been less - and those fin covers pop off very quickly with a 5mm T-handle. Make sure you leave the right front cover off until you finish with the next step!
  • The frustrating surprise will come when you try to drain the water pump. The drain plug is a 17mm plug angled forward in the bottom of the chrome water pump cover, right next to the bend in the header pipe. The service manual says absolutely nothing about this other than to just take out the plug. Good LUCK! Absolutely no way to get on it with normal tools unless you loosen the header pipe. :starz: The good news is that you don't have to actually remove the pipe, just loosen the clamp at the front of the Y joint and remove the two socket head nuts on the header clamp (this is where you will really appreciate the long ball-end allen wrenches for your ratchet!). Once the header pipe is loose enough to pull a bit to the outside near the floor board, it is easy to remove the drain plug with a normal 17mm socket and a wobble extension or u-joint.

 

Now you are ready to put all the drain plugs back in and replace the fin covers (make sure to get that header pipe back in place before you put the right front cover on!). DO NOT over tighten the radiator drain plug - that is all plastic, and the torque spec is ONLY 22 inch pounds. Even with the proper torque wrench, that is so light you can't hardly tell it has clicked, so you could still easily over-tighten and damage it. To me, the right tightness seems to be about what you can do just with your hand on a long 3/8" extension WITHOUT the ratchet.

 

That's it. Only thing left is to mix up 3.5 liters of 50/50 coolant and fill the overflow reservoir to the FULL line, then carefully fill the radiator to the top of the neck. Put the radiator cap back on and run the engine for a minute or so (plenty of fuel in the carbs to do this without the tank) to let the coolant settle, then top off the coolant at the radiator cap. Now put it all back together and take your bike out for a short ride to get the motor fully up to temperature and check for leaks. Then after it completely cools off, check the overflow tank and top up to the Full mark if necessary (if there were any air-pockets left when you filled the coolant, some of the fluid from the overflow tank will be sucked in as the engine cools).

 

METHOD #2 - Skipping the Water Pump Drain (almost as good as #1):

Several folks have said they prefer to just drain the radiator and try to flush the rest of the coolant out with distilled water (see posts below), so I include these corner-cutting options as Methods 2 & 3.

 

  • Drain the radiator and overflow tank as in #1.
  • Now refill the radiator with distilled water (about three liters) and run the engine for at least two minutes. This will not be long enough to heat up the coolant and open the thermostat, but enough coolant will circulate through the vent hols in the thermostat to mostly clear out the water pump and leave only distilled water in it.
  • RE-drain the radiator.
  • Now pull each of the fake fin covers and pop out that little rubber plug. You will notice that coolant that drains from each water jacket still seems bright green, showing the "flush" was incomplete (that's why you are still doing these plugs).

With the radiator plug back in and the fin covers back on, it is time to refill with coolant. But this time you have left some distilled water or highly diluted coolant in the engine, so it is best to not use pre-mixed coolant. Add about 1.75 liters of straight coolant, some to the overflow tank (1/2 full) and the rest to the radiator. Now top up both with distilled water and run the engine for a minute to work out any air pockets, then re-top the radiator with distilled water.

 

METHOD #3 - Short and Sweet and Hope For The Best:

In this method you skip draining both the water pump AND the cylinder water jackets. You will be leaving some of the old coolant in there to mix with the new, but some folks find this OK.

 

  • Drain the radiator and overflow tank as in #1.
  • Now refill the radiator with distilled water (about three liters) and run the engine for at least two minutes. This will not be long enough to heat up the coolant and open the thermostat, but enough coolant will circulate through the vent hols in the thermostat to mostly clear out the water pump and leave only distilled water in it.
  • RE-drain the radiator and flush it again just like above.

After two flushes you probably noticed a much lighter green color to the water on the last drain, so it is time to add new coolant and button it all back up. But remember, not only are you leaving some water/coolant in the water pump, you are also leaving it in the water jackets too, so you need to use a lower amount of new coolant in the fill. My guess of the right mix would be to add only 1.25 liters of coolant and then top it all off with distilled water.

 

That's it folks, all done for another couple of years! My personal choice is Method #1. Even with the need to loosen the header pipe, it really isn't that difficult, and it doesn't take any more time than adding the engine flushes on the other methods. But whichever method you use, it is certainly better than not changing it at all. So now that the maintenance is done, let's rack up some miles!

 

Enjoy the ride! :thumbsup2:

Goose

Edited by V7Goose
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I don't know whether its as good but it sure a lot easier to do it the way I did.

 

Warmed up the engine and then removed the seat, tank, side cover and lower fairing. Loosened the radiator cap and drained the rad. I just siphoned out the overflow tank. Put the plug back and filled it up with distilled water. Ran the engine for 30 seconds or so and drained the rad again (there is enough fuel in the carbs to do this). After one more distilled water flush and drain, I put 1.75 qt of undiluted antifreeze in and topped it off with distilled water. The two distilled water flushes gets rid of almost all the old antifreeze and putting in half the total required amount of undiluted antifreeze with water to top it off accounts for liquid (mostly water after flushing) that didn't get drained out of the system.

 

Although perhaps not quite as thorough, it was quite easy.

 

Ross

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I don't know whether its as good but it sure a lot easier to do it the way I did.

 

Warmed up the engine and then removed the seat, tank, side cover and lower fairing. Loosened the radiator cap and drained the rad. I just siphoned out the overflow tank. Put the plug back and filled it up with distilled water. Ran the engine for 30 seconds or so and drained the rad again (there is enough fuel in the carbs to do this). After one more distilled water flush and drain, I put 1.75 qt of undiluted antifreeze in and topped it off with distilled water. The two distilled water flushes gets rid of almost all the old antifreeze and putting in half the total required amount of undiluted antifreeze with water to top it off accounts for liquid (mostly water after flushing) that didn't get drained out of the system.

 

Although perhaps not quite as thorough, it was quite easy.

 

Ross

Theoretically your method is pretty good, but unless you run the engine long enough to reach full temp and allow the thermostat to open, you are not getting any circulation through the engine. If you want to actually flush the system by mixing the new water with the old coolant, you need to run it a LOT longer. Unfortunately, that requires reconnecting the fuel and makes the bike and water too hot to touch for an hour or two each time.

 

The thermostat doesn't even begin to open until 180 F, which is definitely burning temp, and you need to run it a little beyond that to get a good flush. You can tell when it is ready by feeling the bottom of the radiator. When it is too hot to hold, you have finally gotten the coolant out of the water jackets (and the water is gonna be very close to boiling)!

Goose

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Goose

 

Good point!! I hadn't thought about running long enough to open the thermostat. I guess there was a little more left over than I thought. I suspect that I managed to change out 80% or so and as a result (and the method I used to refill), the overall glycol concentration is a bit higher than the recommended 50%. Better than no change at all but I think I'll run it for awhile and change it again the same way - next time I have a reason to have the tank off the bike. With a couple of thousand km of operation and a second change/flush, there would be VERY little of the original AF left although it does use more antifreeze.

 

Thanks

Ross

Been thinking about this a bit more - it is possible it would work better than just my theory analysis says. There is constantly some coolant circulation through the vent holes in the thermostat, even when cold. And when filling the system, the new fluid must flow down through the radiator and up through the water pump and cylinder water jackets to get to the top, so that might push a higher concentration of the remaining coolant up there for early circulation? If it can be done without heating up the engine, I'm all for it; otherwise, I would stick to the total drain method.

 

The only way we would know for sure is to have someone test it by pulling one of the rubber plugs after the first engine run and drain with just distilled water - the key would be how green that fluid still looked. Not gonna be on my bike, since I just changed it all, but maybe I can find someone local ready for this who will let me help them do the experiment? Any takers in North Texas?

Goose

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OK all, I just got done testing the alternate method of only draining the radiator and flushing with distilled water - it does NOT clear the old coolant from the water jackets.

 

Here is exactly what we did:

 

  • Drained the radiator.
  • Fill with only distilled water.
  • Run engine for approximately two minutes - not long enough to reach operating temp and open the thermostat.
  • Re-drain radiator. First part of the fluid was mostly clear, but then saw some light green, so it was picking up some of the original coolant left in - I suspect it was mostly from the little bit of coolant that circulated through the vent holes in the thermostat to the top of the radiator.
  • Pulled one fin cover and rubber plug - coolant from the water jacket was bright green; therefore, it did not look like it had been diluted to any significant extent from the "flush".
  • At this point decided the flush was ineffective, so pulled the other fin covers; the coolant from all four water jackets was the same - very green.

So here is what I conclude - to get a complete coolant change, you need to drain the radiator AND all four water jackets. I believe that doing one flush with distilled water before draining the water jackets does push enough clean water through the water pump to remove the need to drain that unit. This is good since getting to the water pump drain bolt requires loosening of the right front header pipe.

 

I think the cylinder water jackets retain less coolant than I first stated - maybe a maximum of four ounces each (might even be as little as two), so some of you might think it is just fine to leave that in and let it mix with the fresh coolant. This would be especially OK if you change the coolant every year, but probably not if you stretch it to four or five years between changes! I also think that spinning out the three 5mm socket head screws in each fin cover is so easy that it doesn't make much sense to skip that, but that is just my preference.

 

I will update my first post on this with the new info and move that to the the tech library for future reference.

Goos

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  • 3 months later...

(The information in this post would serve well to be included in the tech library with the other coolant change information.)

 

I changed my coolant the other day for the first time. After reading all of the very helpful posts and the Tech Library, the only thing I noticed was that there were no tips on how to do it without creating a mess, especially when draining the cylinders. Sooo, I spent more time visualizing and figuring than I did actually draining the coolant, but I did come up with a method that resulted in no mess on the engine or floor. This will make my, and hopefully your, next coolant change a little easier and less messy.

 

As well, I found that at 2 inch long screw of the proper thread size was easier to use for pulling the cylinder side drain plugs than using the cumbersome spark plug.

 

I didn't repeat the steps on how to get to the radiator cap and how to remove of the side covers, as this information is already well documented in the tech library.

 

PHOTO 1 - Side Cover Drain Bottle

Get a 16 oz soda bottle, the type that is smooth sided because it flexes better. Cut an angle across the bottom end and cut out room for your fingers to pull the plug on the top side. You can do a few test fits with the bottle to get the angle right. You will need the cap screwed onto the bottle when you use it.

 

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PHOTO 2 - Draining Radiator

Put the bike on a jack and raise it high enough to clear a 5 gallon bucket. Remove the radiator cap, then the radiator drain plug and the radiator will speed dump with no mess.

 

37308.jpg

 

- - - - - - -

 

Next, you will want to grab a large bath towel (preferably not the one your wife just bought at Kohl's). While I only dripped about 1 ounce of coolant onto the towel while draining cylinder 3, I used under the drain bottle on each cylinder to catch any dribbles (and this was the first time I tried this method and didn't know how well it would work).

 

Photos 3-5 illustrate how I placed the towel and the drain bottle for cylinders 1, 3, and 4. (I saved cylinder 2 for last, as it involves making a chute out of packing tape to flow the coolant to the bottle.) The drain plugs are in place in all of the pics, as I took the pics after I drained each cylinder. The coolant in the drain bottle is from the respective cylinder pictured.

 

 

PHOTO 3 - Draining Cylinder 1

 

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PHOTO 4 - Draining Cylinder 3

 

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PHOTO 5 - Draining Cylinder 4

 

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- - - - - - - -

 

The last step is draining cylinder 2. The location of the drain plug for cylinder 2 does not allow for the angling of the drain bottle. I saved this for last because it took a little construction of a chute made of packing tape. Tear three strips of packing tape long enough to go from the side of the cylinder to about 2 or 3 inches past the side of the chrome engine cover. One strip will be the middle strip with the sticky side down. The other two strips get folded in half lengthwise over the left and right third of the middle strip. Then abut one end of this tape contraption to the side of the cylinder and press the center portion down so it sticks to the top of the engine and along the groove of the chrome engine cover. You now have a little rain gutter to carry the coolant to your drain bottle.

 

PHOTO 6 - Cylinder 2 tape chute

 

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PHOTO 7 - Cylinder 2 tape chute viewed from side angle

 

37313.jpg

 

PHOTO 8 - Cylinder 2 draining

 

37314.jpg

 

- - - - - - - - - -

 

My coolant drain amounts were as follows:

 

Radiator - 80 oz (2.5 qts)

Cylinder 1 - 5 oz

Cylinder 2 - 2 oz

Cylinder 3 - 2 oz (this accounts for the 1 oz that spilled into towel)

Cylinder 4 - 3 oz

Reservoir - 10 oz (was at the "Full" line)

Total - 102 oz (3.19 qts)

 

I didn't drain the water pump. Every post I've read and folks I have spoken with said they only got 4 oz, at most, out of the water pump and the headache of getting to the plug outweighed the amount of fluid I would get out.

 

Hope this has been of some help to others out there.

 

Phoenix

 

(If anyone would like higher resolution pics, let me know and I can email the high resolution originals to you.)

Edited by Freebird
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