ST1100 - She's Giving Up Smoking Like A Cigar But Now She's Hot!
- Thread starter Uncle Phil
- Start date
Would the high temp sealant not insulate the sensor if it’s a pipe thread I would use pipe dope
Try riding it locally- say within round on a circle within 50 miles of home- to try to provoke a failure?
Then it's not too far to get it home
ST1100Y
Site Supporter
The w/shop manual clearly indicates to put a dab Hondabond on the threads...
IIRC the bore has a ledge and step on the tip of the probe establishes ground contact...
But increased electrical resistance/bad ground would have the opposite effect:
temp probe resistance:
50°C/122°F: 130~180 Ohm
80°C/176°F: 45~60 Ohm
120°C/258°F: 10~20 Ohm
Brings us back to possible reduced coolant flow, restriction, etc..
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Uncle Phil
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BTDT - see post #192
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Uncle Phil
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Well, Round #2 -
I swapped thermostats yesterday (used a Motorrad compatible one).
Took her for about a 150 mile ride, pushed it hard, it heated up to 1/4 to the right, cool down several times as it should.
Put all the bodywork on this morning so I could take her for another test ride.
Let her heat up to a 1/4 to the right in the driveway, she cooled down as she should in a few miles.
Then she heated up in some traffic and would never cool down past a 1/4 to the right even at 70 mph for a while.
Things I know -
1. Brand new thermostat - doubt it went 'bad' in 175 miles.
2. Gauge/sensor is working properly because the fan kicks in at the 'correct' spot on the gauge - fan circuit is a different sensor/different location.
3. The coolant/engine is hot as the gauge/sensor indicates - the fan kicking on correlates that.
4. This one is probably gonna drive me crazy before I'm done.
BTW, neutral light is also flaky.
This morning I cleaned the clutch switch with contact cleaner, tightened the wire connectors and it started working as normal.
After the ride the light is not working when in neutral.
The only way to start is to pull in the clutch - even if the bike is in neutral.
In neutral (no light showing) if you drop the sidestand, the engine stops (which is normal IIRC).
Is that the diode, the clutch switch or the neutral switch?
I swapped thermostats yesterday (used a Motorrad compatible one).
Took her for about a 150 mile ride, pushed it hard, it heated up to 1/4 to the right, cool down several times as it should.
Put all the bodywork on this morning so I could take her for another test ride.
Let her heat up to a 1/4 to the right in the driveway, she cooled down as she should in a few miles.
Then she heated up in some traffic and would never cool down past a 1/4 to the right even at 70 mph for a while.
Things I know -
1. Brand new thermostat - doubt it went 'bad' in 175 miles.
2. Gauge/sensor is working properly because the fan kicks in at the 'correct' spot on the gauge - fan circuit is a different sensor/different location.
3. The coolant/engine is hot as the gauge/sensor indicates - the fan kicking on correlates that.
4. This one is probably gonna drive me crazy before I'm done.
BTW, neutral light is also flaky.
This morning I cleaned the clutch switch with contact cleaner, tightened the wire connectors and it started working as normal.
After the ride the light is not working when in neutral.
The only way to start is to pull in the clutch - even if the bike is in neutral.
In neutral (no light showing) if you drop the sidestand, the engine stops (which is normal IIRC).
Is that the diode, the clutch switch or the neutral switch?
ST1100Y
Site Supporter
I'd assume a dodgy neutral switch...
coolant stat... dunno, once warmed up my '00 ST also wouldn't "cool down" anymore...
Means the temp needle moves between 1100hrs and 1300hrs...
Sounds like the Neutral switch , or missed plugging it in ,or it fell off. Do you have a known working guage to switch out , correct my memory bike had this problem with the smoking motor before?
Re read last post , on my St when I first got it , she had a intermittent neutral light as well lamp fitting had loosened off , quick fix with a pair of pliers squeezed it a bit and light works and starts in neutral
DJDixon
Site Supporter
I'm really thinking (boy that's dangerous!) that you have something in the radiator that is intermittently blocking some cooling passages. I'd be tempted to swap out the radiator, or at least try to power flush it and see if you get some crud to come out. You have eliminated pretty much everything except the radiator, and some mystery stuff (sometimes) blocking the passages in the radiator seems like a possibility? Other than the bike being cursed, that is...
Like a clear plastic bag
Mind you that was in a gas tank , lets say took a while for a friend (thats a mechanic as well)to figure out why the car would quit . Customer had annoyed someone we figured
bdalameda
PaleoCyclist
I had a weird problem that was similar once when the temperature would intermittently rise for a while and then drop back to normal and everything check out okay. It was the water pump impeller that came loose from the shaft and every now and then it would slip on the shaft and the temperature would rise and then it would catch and spin and the temperature would drop. I don't think I've ever heard of a ST doing this though.
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My ST only had 28,000 km when I got it three years ago and looked pretty clean, when I took the tank, fairings, so on off, everything was pretty clean but under the engine the corrugations were blocked with dirt. Another thing that comes to mind is knocking the freeze plugs out of an engine that I scrapped and finding a fair bit of crud settled in the water jacket below the freeze plug level; no circulation there.
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Uncle Phil
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My next step is to replace the radiator cap, then the two radiator hoses, then the radiator.
How do you power flush a ST1100 radiator?
How do you power flush a ST1100 radiator?
Firehose?
The Bike is possessed and the Power Flush will require a Priest and Exorcism.
In prep for the Exorcism you can remove the bottom hose and thermostat and run water from a hose both directions thru the radiator. Also, one of the chemical engine flush additives before flushing might help. And then there is the water pump impeller that someone mentioned - might be worth looking at too.
Running through the engine block both ways might be helpful too - yet I think the Exorcism might get the best results
In prep for the Exorcism you can remove the bottom hose and thermostat and run water from a hose both directions thru the radiator. Also, one of the chemical engine flush additives before flushing might help. And then there is the water pump impeller that someone mentioned - might be worth looking at too.
Running through the engine block both ways might be helpful too - yet I think the Exorcism might get the best results
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Uncle Phil
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I think this one is going to drive me crazier than I already am!
Got back on it today and installed a brand new Honda Radiator cap.
I noticed the lower radiator hose was leaking a little bit so I repositioned the clamp and tightened it up - no leaks.
Squeezed both hoses to try to make sure there was no air in the system.
Went for a short test ride and everything worked just fine.
Came back, put on all the bodywork (lower cowling, side panels, side inspection panels) and it once again runs hotter than it should (not overheating just hotter than normal).
On the interstate once again and she would not drop below the halfway mark.
This is absolutely maddening to say the least!
The only thing I can figure is with the lower cowling on, the air flow is somewhat restricted and the radiator is not cooling properly.
BTW, the neutral issue was a corroded neutral switch - which I changed out with a new one.
Those are a royal pain in the anatomy to change - even with the fuel tank removed.
Got back on it today and installed a brand new Honda Radiator cap.
I noticed the lower radiator hose was leaking a little bit so I repositioned the clamp and tightened it up - no leaks.
Squeezed both hoses to try to make sure there was no air in the system.
Went for a short test ride and everything worked just fine.
Came back, put on all the bodywork (lower cowling, side panels, side inspection panels) and it once again runs hotter than it should (not overheating just hotter than normal).
On the interstate once again and she would not drop below the halfway mark.
This is absolutely maddening to say the least!
The only thing I can figure is with the lower cowling on, the air flow is somewhat restricted and the radiator is not cooling properly.
BTW, the neutral issue was a corroded neutral switch - which I changed out with a new one.
Those are a royal pain in the anatomy to change - even with the fuel tank removed.
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- 2007 ST1300A
- 2024 Miles
- 001621
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- #9021
UP, if you have not replaced the temp sending unit since installing the most recent non smoking engine see post #19. The last OEM sensor I installed only lasted 4,000 miles.