ST1100 - She's Giving Up Smoking Like A Cigar But Now She's Hot!

Or you can remove middle part of old thermostat and mount it into bike and ride with thermostat still open. If everything goes well and temp will be still very low, than thermostat should be really wrong.
 
dwalby said:
That T-stat fits the ST housing, but its rated for higher coolant flow than the OEM/Stant version, so its not the same as the stock stat. I don't recall what Jim's motivation was, but he wanted to try increasing the coolant flow rate.
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Do you think higher coolant flow rate would be a problem?
Just curious.
 
Uncle Phil said:
Do you think higher coolant flow rate would be a problem?
Just curious.
Click to expand...
I don't know.

if the stat opens at 180F, but flows too much coolant, does that mean the coolant spends less time in the radiator and cools off less? Or, maybe it will still cool off enough, IDK.

since you're trying to debug a coolant temp problem, going to a non-stock stat is just going to add another variable to the equation. The Stant 13868 is the same flow rate as stock.
 
I used standard Japan thermostat which is used at variety of vehicles over last 3 decades - Honda, Mitsu, Daihatsu, Suzuki, Toyota etc and when I compare it to orignal thermostat installed on bike there is really no difference (all cars have also small "air leak" hole as bike).

For example it is Japanparts VT600 (if I remember it right).

After 800km with it my temperature stays still rock solid, doesn´t matter what condition (heat, uphill, etc). When bike is idling at place for long time gauge goes maximum to 1/2 of its movement.

Just sayin :)
 
Larry Fine said:
It theoretically shouldn't. If the coolant flows "too fast" it should close the T-stat a bit.
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Not necessarily. The coolant can actually flow fast enough to NOT cool down, which would increase the temps. Not enough "dwell" time in the heat exchanger. Highly unlikely however.
 
rwthomas1 said:
Not necessarily. The coolant can actually flow fast enough to NOT cool down, which would increase the temps. Not enough "dwell" time in the heat exchanger. Highly unlikely however.
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A T-stat only has direct contact with the coolant attempting to leave the engine. I believe that too-rapid a coolant flow doesn't allow it to stay in the engine long enough to absorb heat.
 
The rest of the story after a 'repair' and a 25 mile test ride (mixed and including interstate)-

1. NOT the Evans Coolant
2. NOT the Water Pump
3. NOT the Gauge
4. NOT the Thermostat
5. NOT the Electrical Grounds
6. WAS the Temp Sensor

I don't like to start changing a bunch of parts at one time because you don't know what fixed it if it gets fixed.
So I approached it with one thing at a time.
I did not think the water pump was bad (given past ST1100 personal history at this low miles).
I did not think the new thermostat was bad since the ST1100 ones are usually pretty good (but I still ordered some just in case).
I've never had a temp gauge (or any other ST1100 gauge) go south (Uncle Phil's Parts House had several in stock just in case).
It just so happened that Uncle Phil's Parts House had a brand new Honda OEM temp sensor - 37750-PC1-004.
And Uncle Phil's Repair Shop could work me in and install it (takes a 12 mm wrench and you do not have to drain the antifreeze if you are quick!).

Now the gauge is working as it should (about 1/4 when running down the road and will return there after being stopped in traffic once you get rolling).
My guess is that my original thermostat is still probably good and it was the sensor the whole time - which would explain the inconsistency.

But the previous 'fix' (thermostat replacement) fixed it for 750 miles so I'll have to do more distance riding to see for sure.
As with many things in life, time will tell.
Thanks to all for your input that gave me some great food for consideration and places to look.
 
Uncle Phil said:
The rest of the story after a 'repair' and a 25 mile test ride (mixed and including interstate)-

1. NOT the Evans Coolant
2. NOT the Water Pump
3. NOT the Gauge
4. NOT the Thermostat
5. NOT the Electrical Grounds
6. WAS the Temp Sensor

I don't like to start changing a bunch of parts at one time because you don't know what fixed it if it gets fixed.
So I approached it with one thing at a time.
I did not think the water pump was bad (given past ST1100 personal history at this low miles).
I did not think the new thermostat was bad since the ST1100 ones are usually pretty good (but I still ordered some just in case).
I've never had a temp gauge (or any other ST1100 gauge) go south (Uncle Phil's Parts House had several in stock just in case).
It just so happened that Uncle Phil's Parts House had a brand new Honda OEM temp sensor - 37750-PC1-004.
And Uncle Phil's Repair Shop could work me in and install it (takes a 12 mm wrench and you do not have to drain the antifreeze if you are quick!).

Now the gauge is working as it should (about 1/4 when running down the road and will return there after being stopped in traffic once you get rolling).
My guess is that my original thermostat is still probably good and it was the sensor the whole time - which would explain the inconsistency.

But the previous 'fix' (thermostat replacement) fixed it for 750 miles so I'll have to do more distance riding to see for sure.
As with many things in life, time will tell.
Thanks to all for your input that gave me some great food for consideration and places to look.
Click to expand...

Thats great. An update on the Evans in the future would be nice as well once you have some miles on it.

RT
 
rwthomas1 said:
Thats great. An update on the Evans in the future would be nice as well once you have some miles on it.

RT
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I've got about 3-4,000 miles on it at this point and so far I am very pleased with it.
And yes you can open the radiator cap when the engine is hot and you will not get scalded! :biggrin:
@bdalameda 's experience is what made me decide to give it a try.
If it lengthens the life of the cooling system (especially the water pump), then it will be well worth it.
 
I ran Evans in my 1100 for about 100K miles and now in my 1300 forever 160K with no problems.
 
I wonder if some of the [probably lower] core passes in your radiator are getting blocked. I don't know if you're able to get your hand against the cores at various elevations and see if all the heat is in the upper passes primarily in the range between hose connections on either tank end, see if you're short circuiting all of your coolant through a limited number of passes.
I suspect on my 13 [although it looks clean inside and only has 40,000 km] that I have very passive flow in the lower portion of my radiator but I haven't had any problems so far. I've also got a partially blocked heater core in a vehicle; hot coolant in / hot coolant out, blows cold air.
You could also buy an el cheapo [we pay about $25.00 at Princess Auto] IR temp gun and see if your coolant in coolant out temperature difference is lower than normal when you know the thermostat is [or should be] wide open. With an IR you could compare that to another 11 see if theirs has a higher temperature drop [between hose connections] with the stat open.
Bad as it was I drove my Honda Accord twenty-five years / 385,000 km [green meant go] With the possible exception of maybe one half of the original coolant change after crashing the rad [it wasn't me].
 
Chris09 said:
I wonder if some of the [probably lower] core passes in your radiator are getting blocked. I don't know if you're able to get your hand against the cores at various elevations and see if all the heat is in the upper passes primarily in the range between hose connections on either tank end, see if you're short circuiting all of your coolant through a limited number of passes.
I suspect on my 13 [although it looks clean inside and only has 40,000 km] that I have very passive flow in the lower portion of my radiator but I haven't had any problems so far. I've also got a partially blocked heater core in a vehicle; hot coolant in / hot coolant out, blows cold air.
You could also buy an el cheapo [we pay about $25.00 at Princess Auto] IR temp gun and see if your coolant in coolant out temperature difference is lower than normal when you know the thermostat is [or should be] wide open. With an IR you could compare that to another 11 see if theirs has a higher temperature drop [between hose connections] with the stat open.
Bad as it was I drove my Honda Accord twenty-five years / 385,000 km [green meant go] With the possible exception of maybe one half of the original coolant change after crashing the rad [it wasn't me].
Click to expand...
As I said, it's working fine now after I changed the temp sensor.
But I also bought a IR just to see as part of the process and the readings looked pretty 'normal' to me given the stat should open at about 180.
 
Unfortunately, SweetTreat - the one I just replaced the engine in - is now smoking like a cigar on fire and missing on at least one cylinder.
It appears that the right rear cylinder is sucking oil as the plug is wet after cleaning and reinstalling.
The oil level is correct (not overfilled - I checked the air cleaner to be sure there was no oil in there).
Never overheated, good oil (Mobil 1 Motorcycle), proper coolant levels, 45,000 miles (5,000 miles since I did the swap) and looks like this engine is toast. :(
This one is a real puzzler ... :think1:
Any ideas?
 
Hey UP.
Curious was that plug wet with fuel or oil? Seems uncommon for that engine if it was burning it but smoking is never a good sign. Supposed to be pretty iron-clad. Can you perform a compression test? I did wonder if it was a plug wire or coil?
 
I'm sure you have already confirmed the wetness is oil and not gas or water. I wonder if an engine repair can be done, if needed, without pulling the motor like one might do on some cars. Pull the head, oil pan, rod bolts, and remove the piston if needed......
 
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