Alright, so I went throught the coolant flush process as outlined in the service manual -

open the water pump and cylinder drains, unhook the radiator siphon, rinse the overflow (I added flush the system with water as well). Then I retorqued the drain bolts (new washers of course), put the siphon back on, and filled the radiator and overflow as directed - though it only took 2 quarts of Engine Ice. When I did the little throttle blip thing, the coolant level didn't decrease at all.

So my question is: do I have water or air in the system? I rode the bike for 10 minutes, got it to roughly 200F and there was absolutely no change in the level in the radiator or overflow. If it's water I don't mind since I'll be flushing this again in the fall, but I don't want to go to the first trackday of the year this Saturday and blow up my engine.

Any tips would be much appreciated. I don't mind popping off the fairing again - I'm getting to be an old pro at this. Incidentally, I've been leaving off the bodywork clips that mate the inner side to outer side fairings - really speeds up the process.

 

I used one of those flush kits where you connect a garden hose to the radiator. Flush until you see crystal clear water... then blow it ALL out (as much as your little lungs ca, anyway) until no more comes out.

It could be air in the lines, and to be honest, that's most likely. Put your bike on a stand and remove the radiator cap and coolant overflow cap (otherwise it's a vaccum and won't circulate... think bleeding freshly installed brake lines). Some people unplug a vent plug but I don't and I don't know which one is which - never cared to look.

Start the bike and let it run and see if it circulates or drops now. If it doesn't, you could always get a foot pump from the dollar store or something and bleed the system manually. Let us know how it goes and what you find out.

 

FWIW, 200 degrees is a normal operating temp for city riding. What were the conditions you were riding in? 219 degrees for any period of time is when it's time to be concerned.

 

Oh, I wasn't worried about the temperature, I was just saying - I really warmed the thing up and gave the coolant a chance to circulate. I'll uncover both caps and will run the thing for awhile.

I have a compressor, but I've never bled a system that way - would I just be forcing air into the top of the radiator?

 

Well, I tried again tonight after I got home from work - took off the radiator fill cap, turned on the motor, and really let it warm up.

I rocked it back and forth, blipped the throttle,and the level never went down. I let the bike idle all the way to 200, at which point coolant started bubbling up the neck. It was green, ethlyene glycol coolant! Apparently the flush I did wasn't very good. I'm going to use a pressurized flush next time, but as it stands I don't have the time to do a proper flush. I'm guessing there's probably 1/2 quart of diluted ethylene glycol in there with my engine ice. If I have overheating problems I'll address this again, but as it stands it's going to wait till the fall.

 

ajohn - I did mine the same way, and came up with the same question. I've been riding with it that way for 2 years and haven't had any issue.

my 2c