So I got the bike out of storage and did the post winter work on her over the weekend, and then took her out for a test ride and I seem to have a cooling issue.

The bike is getting into the critical temp range (where the temp gauge flashes). I did a full coolant change with the service.

So I am looking for ideas about where to start....

I have one clue so far, I don't think the fan ever came on so maybe I have managed to pull the cable loose while I was working on it.

Suggestions?

 

your thermostat could be caught closed from sitting there, all corroded and such. my fan precisely comes on just a tad over the half way mark, for starters.

 

Agreed on the thermostat.

 

Coolant guage flashes? Huh, didn't know that. Never got that hot. Good to know so if it ever happens I'm not like WTF. Haha

 

Well this is an '04 so it has a digital gauge rather than analogue, but yes if you have a digital one, then it flashes when it gets upset.

 

I presume that you followed the manual regarding bleeding the system after flushing?

 

For everything except having it on the side stand, I had it up on paddock stands, I am thinking I may have an air lock in the system. Tonight I am going to pull the fairing and check the cables and make sure there is no air in the system.

 

Absolutely right, the point of having it on the sidestand is to make sure that the cap is the highest point in the system, allowing the bubble to escape. Make sure you rev it several times too.
Might pay to check the fan is not stalled - sometimes stones can work in to the housing and jam the mechanism.

 

Ok so I ran the blead proceedure from the manual again, on the side stand this time and still have an overheating issue.

Doing a quick seat of the pants temperature measurement I found that the bottom inter radiator tube was cold and slightly swollen. So I pulled the tube and drained the radiators to see if there was a blockage, but there wasn't. Next I pulled the cover off the water pump and it all looked ok a little gunk but nothing major. I spun the engine briefly and the water pump was not spinning is this normal?

I then pulled the tank and the air box to check that the thermostat was ok, dumped it in a pan of boiling water and it opened up at least 10mm which seemed to be withing spec. I didn't have a thermometer so I could not test the real thermal point.

So I put it all back to gather and ran it again, still overheating.... This time the when I inspected the temps, all of the radiators where cold and only the top tube into the left hand radiator was hot.

Seems that the thermostat is not the issue, could I have sheared water pump drive?

 

Radiator caps go bad too. See if you can test that. If it were me, I would just buy a new thermostat and cap and put them on. Your symptions point to that. After that, you may have blockage, but it seems premature to say that.

The below came from hawkworks.net (a site for the NT650), this may work on a Super Hawk as well if you are looking to save some $.

replacement (cheap) thermostat

Stant 180° part number 35788 or BT 378 180


.:Hawkeye:. sez:

• The photos show the Stant number you need. I had to grind a little off thepin to clear the top half of the housing, and grind one millimeter off theradius to seat it in the lower housing. Final mod is to drill the by-passhole (no typo this time). Final photo shows the saucepan test with an ASTMcertified thermometer (thank you Weyerhaeuser lab). It starts to open at180 deg and is fully open by about 190. .:Hawkeye:.'s page on this.

• Cheap replacement radiator cap
  
  Napa small radiator cap part number 703-2443
  interchangable with 703-1443

 

The last time I had a rad cap issue the bike was dumping all the coolant rather than overheating. I still think I have a pump issue... I am thinking of pulling off the engine case tomorrow night to check the drive.

I want to make sure I am spending money in the right place, as I have already put 500+ bucks into her this season..

I just wanna get out and ride......

 

A crude pump check:

engine cold, start bike with rad-cap off, blip the throttle a couple of times. When you do so, the fluid level should drop and rise in sync with the throttle blipping. If not, you have a pump issues.

 

I believe the water pump should be turning anytime the engine is running.

 

Correct, this will check to see if it is pumping coolant as opposed to just spinning.

 

It seems we have a winner

Also do I have to drain the Oil to remove the right crank case?

 

I realised how silly my question was when I got back oh well.

But I have found the source.... It seems the water impeller shaft has sheared off... see images. The question now is where the F is the bit that is no longer attached... I think it may have fallen out the back of the water pump gear, but that looks like its gonna be a real pig to remove....

 

Can anyone tell me what range the temp is under normal operation? i have an 2003.

 

Mine(04) usually runs between 190f and 220f depending on weather, traffic and riding etc..

 

My '01, on the Celsius scale, runs in the high 70's to no more than 104 depending on the factors that thatbloke set out.

 

i picked the bike up yesterday, 2003 with 5400 miles on it. bone stock. the fan came on at around 220. my VFR 800 is about the same. the SupreHawk didnt go above around 225. with the fan running the temp went down, but to only around 200F. has anybody tried water wetter? i hear its good to cut a few degrees. also syntethic oil. let me know. thanks for helping me.

 

The thermostat begins to open at 165 F and is fully open at 195 F, my cooling fan kicks on at 210 F and it never gets hotter than that. in traffic it runs about 195-210 F depending on how long I am stoped, and on the highway it runs about 175 F. The thermostat and cooling fan thermoswitch are both brand new as well as the coolant.

 

I run water wetter in my '02 and it seems to work, temp is usually under 180 under normal cruising.

 

Going back to the original post, what has been done to shear the pump shaft? That's something that really surprises me...

 

I believe the cause of this is stupidity on my part.. I had to move the bike in the middle of the winter (I'm in Chicago so it was well bellow freezing) but did not do any suitable winter prep before the cold set in.... And as such she was left with water wetter in and no antifreeze....

I think I have learnt a valuable lesson here.... Either find heated storage for the winter or stop being lazy and do the prep work...

 

Anyone know at what temp it begins flashing? I've been hitting 220/225* when it's hot and muggy....traveling at 65-70mph+.

Even this morning when it was about 65* out, my digital temp was hitting 210*.

I'm thinking of flushing the system and adding some Wetter, but it's still a nice color of green in the reservoir.

Curious as to what the danger,danger temp is on the Superhawk.....

 

Much higher than that... Dunno where it starts flashing the numbers, but the scale goes to 270...

 

Read that in the service manual...curious as to when damage begins...nice to know it's the numbers that flash...at that point, I wouldn't hesitate to pull over and let 'er cool off.

Not sure if it's mental, but I feel a slight performance drop when it gets to around 220/225*. Probably in my head.

 

Well... I wouldn't start worrying until you hit 240 ish at least...

 

If I find out what temp it flashes, at...I'll post back to let you know.