Cooling Problems

[backlander]

Scenario: Two day trip involving three states.
First leg, Ark to Texas: At fifty mile out, coolant soaks right leg coming from across top of carbs from underneath fairing.
At sixty mile out. Happens again. No further problems, temp gauge running normal.
Second Leg, Texas to Louisiana: At sixty miles out, got sprayed with coolant again. I found a closed service station, got under the canopy in the shade and proceeded to show the other six riders how to strip the top of a gold wing in five minutes or less. :smilie_happy: We found that the coolant recovery line had broke into near the radiator. Repaired it, refilled the radiator and were back on the road in thirty minutes. Temperature remained normal, finished trip into Louisiana.

Third leg,Louisiana back into Arkansas: After about 75 miles the temperature gauge began to rise again to near red line like the other times, but there was no coolant spray to my leg. At about 12 miles from home the temp gauge pegged out, max, so I slowed and limped home, coasting downhill to get from building up engine heat, parked it under shed. The radiator fan is working, auto and manual. Thermostat, hoses, everything is approx. 1 1/2 years old. I was too tired to work on it so I left it for the night. Cranked it up this morning, runs great, no steam, no missing.

At no time has there been any leaks of coolant show up while it was parked, cold or hot. No steaming out the exhaust at all.

Opinions on cause are welcome, I'm thinking the thermostat is sticking occasionally.

 

[ekvh]

I'll bet your thinking is right.

 

[OldWrench]

A few years ago I began having a heating problem. I finally removed the grill from the radiator and found the radiator had a lot of road dirt and grime in it. Cleaned the radiator and have had no more heating problem. Lets face it the radiator is right behind the front tire, whenever that tire picks up dirt, mud, or whatever it can accumulate in the radiator fins reducing the air flow through the radiator.
Also don't ever mix long life antifreeze with standard, the two are not compatible and will cause hot spots in your heads.

 

[backlander]

I hear what your saying Oldwrench, six thousand miles ago, this bike received a complete mechanical refresh, including the radiator, new 50/50 coolant, and I ride all highway except for my 400 ft driveway. The problem is sporadic so it has to be a part time mechanical failure of a cooling system part.

 

[Steve83]

+1 on both - thermostat sticking, and a good radiator cleaning.

 

[joedrum]

hmmm this is reason i never have thermostat in place ... this time of yr its a complete discount .... but i also agree with oldwrench and clean radiator makes for good cooling ... also 1200 radiators are smaller than 1000 or 1100 radiators... but me id pull thermostat and see what happens ... when down in florida it was the only way to deal with stop and go traffic in 100 degree heat and 100% humidity

 

[mcgovern61]

What about a bad gauge? I would test the cooling system with an infra red temp gun and verify that the system is actually getting that hot? It would not be the first time a gauge failed to read correctly.

You can also test the thermostat with it by checking the in and out temps at the thermostat and verify the temp it is opening and closing. (Sure beats pulling everything apart for testing!)

 

[backlander]

Good idea Gerry, I'll do that. Thanks !!

 

[dan filipi]

Sure makes a guy want an air cooled engine.

Intermittent always hard to locate problem.
Hopefully it's not a blown head gasket.
I had one and showed no signs of it other than running hot.
Check for any bubbles coming into the reservoir.

 

[Omega Man]

What about that thing in the gauges that can cause a guage to peg? 7v resistor?

 

[backlander]

I'll keep that in mind Dan, sure hope that's not the problem, so far no mixture of oil/water in either direction or external leakage.
Randy, the 86 Aspy has LCD electronic dash and the gauge appears to be functioning correctly as far as I can tell, cold on crank, gradually warming as it runs, shows normal most of the time, gets warmer as it should and cycles with the fan when it come on and off,then all of a sudden it will start climbing and peg out in the red, you can feel the heat increase off the engine. Then sometimes it will return to normal gradually and run fine, no longer smelling the "hot" fumes coming off the engine.

 

[Ansimp]

I would replace the thermostat, any other scenario is way more expensive. Is it possible that the impeller on your rebuilt water pump could slip or cavitate ? I still believe a faulty thermostat is most likely as the overheating situation comes and goes. Good luck Mike!

 

[backlander]

Thanks Tony, I'm going to start on it in couple of days, resting up from the three state ride we were on this week end when it happened. I don't think the impeller could slip, it's a solid press fit onto shaft and I added locktite to for insurance. I'm pretty convinced it's the thermostat.

 

[Steve83]

A sticking thermostat will cause the exact conditions you describe. When I tested the one from my '83 during the rebuild, it opened very slightly, then stuck there. As the temp of the oil I was using got close to 200 degrees, it suddenly popped open, so something was binding it up. New replacements are cheap and plentiful.

 

[backlander]

Thanks Steve, even though it's only a year or so old, new stuff can fail, thermostat is my opinion also. It's ironic, the one I took out of it then was probably 27 years old. There was nothing wrong with the old one, I kept it but I've got a new spare I'll use.

I wish there was some way to install a valve so the thermostat could be bypassed in the summer months and used in the winter months. Probably just wishful thinking.

 

[dan filipi]

I compared closely the supposed 'crossover' t-stat that's listed on the forums as compatible and found they have a smaller center opening. My opinion is order a Honda OEM for it.

 

[Winger 82]

my $'s on the thermostat

 

[backlander]

+1 Dan and Winger. Thanks.

 

[joedrum]

i like the bypass hole you have when you toss the thermostat .... :smilie_happy:

 

[backlander]

:headscratch: How did I know that would come from you joedrum. :smilie_happy: :smilie_happy: Started stripping her down this morning, drained the liquids and like I said earlier, no contamination in either direction. It was time for an oil change anyway so no loss there. Problem noted, only about a pint of coolant left in system when drained, also recovery tank tube broken in rubber fitting. All I got left is undo the radiator hoses and drop it out of the way. Hot, humid and I tire real easy right now, so it will have to wait until tomorrow. Be glad when my doctors figure out what's going on with me.