Some Tips on Changing the 2nd Gen Coolant

[V7Goose]

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. 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!

Goose

Edited June 21, 2009 by V7Goose
Updated to match what I put in the Tech Library

[Kregerdoodle]

Thanks for the info Goose... I have that on my list of items to take care of in the next few weeks... Good info..

 

K

[RossKean]

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

[V7Goose]

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

[RossKean]

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

[frogmaster]

Maybe place this in the Tech Library for easy find in future?

 

TY

[Guest curtismiller]

Goose,Glymer should hire you to rewrite their instructions on this.Time to do mine and thanks. curtis

[GeorgeS]

Drain at plug under water pump. ( easy )

Siphon out the overflow tank.

Fill system with water hose, Run engine, to operating temp.

 

Drain again, at plug under water pump . Refill with water, Run engine, and drain.

 

Rinse out overflow, tank. ( maby repeat, refill with water, and run to temp )

 

Add, 1 1/2 Qt Anti freze, and 1 1/2 Qt Distilled water. Go for a drive.

 

Next day, top off overflow tank with 50/50 mix antifreez.

 

Nothing to remove except the Drain plug, at pump, and Radiator Cap !!

 

Its easy, works just fine. Seems like this should work on a 2nd Gen also.

[V7Goose]

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

[LilBeaver]

Geographically I am in north Texas but I know the native Texans [around here at least] get all bent out of shape when I say that... Regardless, I'd be game to give this a shot. I think the only fluid that I haven't flushed yet is the coolant, and I am looking to do that pretty soon...

I'd be happy to buzz down there on a weekend or something to give this a try if you want.

 

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

[V7Goose]

Geographically I am in north Texas but I know the native Texans [around here at least] get all bent out of shape when I say that... Regardless, I'd be game to give this a shot. I think the only fluid that I haven't flushed yet is the coolant, and I am looking to do that pretty soon...

I'd be happy to buzz down there on a weekend or something to give this a try if you want.

Well Sir, I'm here, and weekdays or weekends are all the same to me. Bring that thing on over and we'll pick up some beer so we can tell lies and stare at it for a while!

Goose

[tsigwing]

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

 

We could try mine on Saturday, since I will be over anyways and have been meaning to change mine (its still original).

[V7Goose]

We could try mine on Saturday, since I will be over anyways and have been meaning to change mine (its still original).

That's a deal. Just bring some coolant and a couple of gallons of distilled water. You will need at least two, two and a half if we flush it twice.

Goose

[Redneck]

Well Sir, I'm here, and weekdays or weekends are all the same to me. Bring that thing on over and we'll pick up some beer so we can tell lies and stare at it for a while!

Goose

I never thought of that (flushing it with beer)

[tsigwing]

That's a deal. Just bring some coolant and a couple of gallons of distilled water. You will need at least two, two and a half if we flush it twice.

Goose

 

 

Hmmm a 12 pack of beer, a jug of coolant, a couple of gallons of distilled water...that's going to be an interesting trip on the RSTD...

[RossKean]

The first flush was quite green but there was quite a bit less color in the second flush. This only means anything if there isn't a dead zone where the AF doesn't circulate. Anyway, I'm happy with the change and will probably give it another flush in the Spring.

 

Ross

[V7Goose]

Hmmm a 12 pack of beer, a jug of coolant, a couple of gallons of distilled water...that's going to be an interesting trip on the RSTD...

See, that's why you need an RSV; I can carry twice that without even having to think about using the trunk rack! (and I could throw on a 50lb bag of dog food too!)

Goose

[1sttenor]

I drained mine last week as I was putting in a new temp gauge. While I had the plug out of the top of the cylinder using Goose's method of installing a sensor (Thanks for a great article Goose) I drained the fluid. While that plug is out you seem to get it all out. I pulled the rubber plugs and not another drop came out. So the next time I do a coolant change I may just remove my temp sensor and the reinstall. For what it’s worth.

 

P.S. If the top plug is out when you remove the lower radiator plug, YOU WILL GET EVERYTHING WET, including you, the floor, your tools, anything within 6 feet of your bike and your neighbor's interested cat.

 

 

(Ask me how I know!)

Edited June 18, 2009 by 1sttenor

[Guest HdHtr]

Hmmm a 12 pack of beer, a jug of coolant, a couple of gallons of distilled water...that's going to be an interesting trip on the RSTD...

 

 

I was wondering that myself ... never thought to use beer for antifreeze ... bye the way ... what's the freezing temperature of beer? When you warm it up ... it gonna belch or ...??

[Leland]

I removed the floor board to gain access to remove the water pump drain plug. Won't be removing that plug again anytime soon. Only about a ¼ cup of AF drained out of it after all of that.

[V7Goose]

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

[V7Goose]

I drained mine last week as I was putting in a new temp gauge. While I had the plug out of the top of the cylinder using Goose's method of installing a sensor (Thanks for a great article Goose) I drained the fluid. While that plug is out you seem to get it all out. I pulled the rubber plugs and not another drop came out. So the next time I do a coolant change I may just remove my temp sensor and the reinstall. For what it’s worth.

 

P.S. If the top plug is out when you remove the lower radiator plug, YOU WILL GET EVERYTHING WET, including you, the floor, your tools, anything within 6 feet of your bike and your neighbor's interested cat.

(Ask me how I know!)

I'm not sure I can completely explain your experience, but I'll try.

 

Removing one of the water jacket plugs from the cylinder heads that do not already have a coolant return connection is identical to removing the radiator cap under the tank. In fact, removing the radiator cap is a little better since the air it lets in allows the coolant return pipe on the right side of the frame to drain quickly too.

 

For this next step, the key difference may be if you do it on the side stand or on a maintenance stand that hold the bike straight. I do my work with the bike straight up, and after a full drain of the coolant, each cylinder water jacket still retains several ounces. ALL of them drain equally when I remove the rubber plugs. This is why the shop manual tells you to drain each cylinder water jacket separately. MAYBE, when you did your test, you had the bike on the side stand and then pulled one of the plugs from the RIGHT side of the bike? This would have allowed the remaining coolant in that water jacket to pool to the left and not drain, the same way changing the clutch while the bike is on the side stand does not allow any oil to spill. That is my best guess.

Goose

[jneed53]

Goose -- I'm up for it also. You helped me with my clutch spring. I could make it over just about any time. Let me know.

[RandyR]

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.
  

 

Goose,

 

What if you ran it long enough to open the thermostat? Then another few minutes.

 

Wouldn't that evenly dilute the old antifreeze enough?

 

RandyR

[V7Goose]

Goose,

 

What if you ran it long enough to open the thermostat? Then another few minutes.

 

Wouldn't that evenly dilute the old antifreeze enough?

 

RandyR

Yes, if you let it reach normal operating temp so the thermostat was open and then a short while to allow full mixing of the coolant, you would get a good flush. The problem with that is the hot coolant would be difficult and dangerous to try and drain without waiting for the engine to cool off again. If you are going to go through all that, why not just take the extra 10 minutes to pull the fin covers and drain the water jackets?

Goose