Motorcycle Repair: Coolant spilled out of my Shadow, coolant level, overflow tube

Question
Hi Falcon,
When I originally checked the coolant level on the bike, it was while it was cool and I check the level in the reserve tank, per the manual.  Do you still think it's a problem with the thermostat?  There is no information in the manual about the thermostat, so I don't know how to check it or where to look for it on the bike.  

Thanks,
Bel

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Followup To
Question -
Hi Falcon,

I have a '95 Honda Shadow Deluxe 600cc.  I rode my bike yesterday for about 30 minutes, on my commute home from work.  When I parked the bike in the garage I noticed that coolant was draining out of a black tube underneath the bike onto the ground.  The black tube is connected to the coolant reservior.  

I checked the coolant level a couple of weeks ago and it looked fine.  This has never happened before and I don't believe the engine light came on.  I added some distilled water to the coolant reservior this morning to check for leaks and to see if it would drain out thru the tube again.  It did not.

What do you think happened and why?  Should I flush out the system and add new coolant or should I just bring it in to a service rep?

I would appreciate any insight you can give me on this problem.  

Thanks,
Bel

p.s. how did you get the name Falcon?


Answer -
Hi Bel.
 The black tube that the coolant came out of is an overflow tube.  When the coolant pressure reaches a certain level, the coolant flows into the reservior, which is actually an overflow tank.  When that tank is full, it begins expelling coolant through the overflow.

When you checked the coolant level, did you check it at the tank or in the cooling system with the engine cold?

If you checked the coolant level in the radiator and it was ok, then you may want to check the system.  You could have a bad thermostat.  The manual has the specs and specific testing instructions for it and it is fairly simple to replace if it is bad.

Let me know what you find.
Good luck.
FALCON

P.S. I don't remember how I got the handle FALCON, since I got it about 25 years ago while I was in the Army.

Answer
Hi Bel.
 Was the manual you referred to the repair (service) manual or the owner's manual?  I know that the owner's manual will not have anything about the thermostat, but the repair manual will have that info in the section on the cooling system.  It may be buried a bit, but it will be in there.

In most every system that I have seen, the thermostat will be in a metal "bulb" with a coolant hose at each end.  It will, normally, also have a wire connected to it, which is connected to the overheat warning light on the bike.  The like to hide them under the cosmetic pieces on the bike near the radiator.

There is also the possibility that you could have a failed/failing water pump.  Those are the absolute likeliest culprits in this case.

Good luck.
FALCON