Overheating

[acee125]

So on my way to work this morning after about 10 min of riding the temp gauge started going past the halfway point which I heard was bad. I slowed down so the bike is only at 4k in hopes of lowering the temperature but it still kept climbing.

I pulled over and noticed coolant coming out of the outermost hose going into the water pump (it also soaked my right foot and sprayed coolant on the exhaust and side of the rear tire). I'm hoping that I only have a bad thermostat.

I'm trying to think of why it came out of that hose though? I had clamped on their pretty tight I thought which would mean that there would have to be substantial pressure coming from that area. I popped the side cover and the overflow reservoir was at the correct level.

I haven't torn it apart yet and won't get a chance to until next week. With the coolant coming back out of the hose by the water pump and the reservoir being full it makes me think that something is plugging the hole or restricting flow somehow so it backed up and forced its way out of the hose.

Right now it's all speculation.

Any thoughts?

Oh, and the stumble came back too. At least I had one nice day with a clean running Vision.

[h2olawyer]

Actually, the temp gauge will swing through quite a range, depending on your riding environment.  The only time to get worried is if it gets to the top of the green zone.  Mine consistently runs in the upper half of the range.  It is also why many of us have added a fan override switch, so the fan can be turned on earlier than the sensor says.  It's just a matter of hooking up a secondary ground circuit through a switch.

As for your leak, that's a new one to me.  Take the thermostat out & give it a look over.  There's a test method in the manuals.  There is also supposed to be a small hole at the top.  Possibly, a thermostat replacement without the hole was used or the thermostat was reinstalled incorrectly.  I know there's an automotive thermostat that works (you may need to drill the hole), but I don't recall exactly which one it is.

Glad the spray on your tire didn't cause a crash.  Coolant is slick!!!

H₂O

[acee125]

My temp gauge generally sits just a hair to the left of straight up and down.

[h2olawyer]

Mine rarely stays below the 1/2 mark.  In stop & go traffic, it gets nearly to the top of the green zone - even with the fan running.  When following cars up canyon roads, the temp will climb as well - to around the 2/3 or 3/4 level.  It's done this since the bike was brand new.  The switch installation allows me to turn the fan on in those higher temp situations before the temp climbs.  It still gets fairly warm, but takes much longer to do so.

H₂O

[acee125]

The only thing that make me suspect is that I've done this ride many times before and it hasn't given me any trouble and the needle stay the same. Maybe the hose was loose after all and the temp went up because instead of the coolant circulating some of it was leaking...?

[acee125]

Well, I think I have a flow problem. I tighted the clamp of the hose(it wasn't really loose, just not as tight as it could go) that was leaking and started the bike. I let it idle for about 5 min.

The temp gauge hadn't moved so I touched the sides of the cyclinders. The front one was warm and the rear one was hot. There was definately a big difference. The front exhaust pipes were also warm to the touch but not hot and again the rear y pipe was hot.

If you're on the left side of the bike looking at the rear cyclinder, I pinched the hose (coolant hose?) on the top rearward part of the cylinder/valve cover. I expected to feel some resistance but there wasn't any (no coolant=no flow?).

I also checked the radiator and overflow tank before I started it and they were both full!??? I "burped" the system when I originally filled the radiator.

Plugged hose maybe? No flow=bad thermostat

[Rick G]

I've never seen a plugged hose. Your thermostat could be bad, it simple to check . Put it in a pan of water on the stove, and turn on the burner. You will need a thermometer to know what the temp is, when it opens.
The automotive thermostat that I use , is from a 4 cylinder Chevy , early '80 vintage . The part number is in the parts list .
Mine will run around the middle of the guage, but in summer , here , I have climbed up from the river to Oatman and it was just kissing the red zone when I shut off.

[kwells]

If you're going through the trouble of boiling it and recording temps...just get a new one and save urself the headache.  7 bucks well spent

[Rick G]

Kwells , I use the information, ie: was the tstat bad or not , to know weather  or not i need to search further. but yes, if I know the bike , well, I will just stick a new one in.

[kwells]

yah...understood

[jasonm.]

you simply have a bad hose. If the system overheats the coolant actually should dump out the recovery bottle under the seat thru a clear hose. Check your hoses......oh I see you did that. Thermostats do go bad but as I said...over heating does not cause hoses to loosen or leak... unless otherwise bad.

[acee125]

I haven't checked all the hoses yet...