I Guess the Super Ténéré is just a Warm Weather Bike

[Spider]

KSH, I'm wondering if the mileage difference is exaggerated by the fact that your regular ride is for less than 10 miles. Agree that the drop in temp along the way sounds like a stuck thermostat, which would also contribute. But no engine reaches its maximum efficiency until it is well warmed up...that's why a lot of hybrid cars actually have a thermos to keep the coolant warm overnight...it lets them warm up faster.

Anyway, looking forward to hearing what you figure out. I don't ride a regular route, so can't compare apples to apples. I do know all my other vehicles get worse mileage in cold weather.

 

[JHKolb]

In your fuel mileage comparisons, are you topping off the tank from the same location? I often see some (though small) differences in my mileage when I fill at different gas stations.

Also, is the fuel in your state switched over to a winter fuel mix? I know they (the refineries) used to switch over to a different mix for emissions in the winter months, could this be related to your issue?

http://auto.howstuffworks.com/fuel-efficiency/fuel-consumption/summer-fuel1.htm

 

[DukeTen]

Can you guys stop saying "Winter" the more you say it, the quicker it will be here. ::016::
I just change the oil from factory 20w40 to 10w 40 Yamalube. With the factoy oil, I did notice the temp would rise and fall depending on the riding. Now with the new oil, its stays constant around 170ish and is been near 60 degree during the day and almost 38 degrees at night. The last three days. MPG has be steady at 47.5- 48.5 sorry to brag but it 60mph all the way to work.

I'm on my second tank only and the mileage seems to be improving from the first (as expected). That said, I have noticed significant coolant temperature changes depending on the outside temperature, riding conditions, etc. I live in high-desert climate, which means temperatures go from 50's to 80"s this time of the year. My previous bikes seemed to keep the engine at more constant temperatures (no digital displays though). How much variation should be considered "normal" on the S10?

 

[Buckeye56]

My ST1300 had a stuck thermostat and it would cause the milage to drop by around 7 MPG in cold weather. I had a devil of a time getting it fixed. The bike was under warranty but it took three tries at three dealers before it was corrected.

 

[KSH]

The last tank was 35.16 mpg's.
I was able to ride 100+ miles tonight with low 50 degree temps and my guess I will be lucky to get into the 40's.

This weekend I will be removing the thermostat to test it, if it tests out OK, I will be installing a weather from to help keep the engine up to temp and see if that helps.

Edited
This is a fuel injected engine, in theory the cooler temps should allow you to produce more power thus over coming the friction the lubes have at lower temps. On a carb unit's you install larger jets in lower temps to produce the same power and the fuel injection should be doing this for me and it is over compensating.

 

[Bappo]

Last weekend I ran a 240 mile tank in 40 degrees at 70 mph avg. and was at 52mpg. Calculated. Worst tank for me was across highway 50 in Nevada with strong winds and speeds up to triple digits and it was 42 mpg at about 65 degrees. Will have 30 degree weather soon so i can check on differences. One thing I noticed is the mpg really starts to drop off after 75 mph indicated.

Bappo

 

[Tremor38]

The last tank was 35.16 mpg's.
I was able to ride 100+ miles tonight with low 50 degree temps and my guess I will be lucky to get into the 40's.

This weekend I will be removing the thermostat to test it, if it tests out OK, I will be installing a weather from to help keep the engine up to temp and see if that helps.

This is a fuel injected engine, in theory the cooler temps should allow you to produce more power thus over coming the friction the lubes have at lower temps. On a carb unit's you install smaller jets in lower temps to produce the same power and the fuel injection should be doing this for me and it is not.

Well, then we went to different schools and I hope somebody can jump in to provide some balance to the discussion. Maybe I'm mis-interpreting what your are saying.

Fuel injection ensures that you're not too rich and not too lean, by maintaining the proper AFR. When the air gets colder, and thus more dense, this results in a lean condition, and the EFI compensates by richening the mixture (adding fuel). Compensating for the increased power developed by the lean condition is not the concern, but keeping you out of a lean condition that can causes damage to the engine's top-end because of excessive heat is. Same thing is done manually with carb jetting. When the air gets colder, you go with larger jets in order to stay out of a lean condition. Going smaller will raise the temps even further.

So, maybe you are trying to say that the S10's EFI is over compensating? I'm not trying to insult youre intelligence, so if there is something I'm not understanding in your post, let me know. What I'm reading seems to be 180 deg out from the norm though.

 

[behindbars]

How much variation should be considered "normal" on the S10?

According to the service manual, the thermostat begins to open around 156 deg. F and should be fully open at 183 deg. F. The coolant temp sensor is mounted right next to the thermostat so I would expect to see the temp display within this range during normal riding conditions.

Steve

 

[KSH]

So, maybe you are trying to say that the S10's EFI is over compensating? I'm not trying to insult youre intelligence, so if there is something I'm not understanding in your post, let me know. What I'm reading seems to be 180 deg out from the norm though.

Yes, it is over compensating. It's a sensor and I just need to find which one.

Thanks for politely calling me a flipping idiot and getting me pointed back in the right direction.
::003::

 

[Tremor38]

Yes, it is over compensating. It's a sensor and I just need to find which one.

Thanks for politely calling me a flipping idiot and getting me pointed back in the right direction.
::003::

Haha! No, you're far from that. I get frequently get wrapped around the axle with the rich/lean thang, especially if I'm chewing gum

 

[dcstrom]

This weekend I will be removing the thermostat to test it, if it tests out OK, I will be installing a weather from to help keep the engine up to temp and see if that helps.

Did your dealer refuse to check it for you? Seems to me it would be a warranty issue - if the thermostat IS faulty, it's unlikely/impossible for Yam to give you a new one if you didn't go through the dealer?

FYI, my mileage is averaging 42 - usually less than that around town - 38 - except for this week, temps are cooler and I got... 42. I think you may be on the right track with the thermostat.

 

[KSH]

Did your dealer refuse to check it for you? Seems to me it would be a warranty issue - if the thermostat IS faulty, it's unlikely/impossible for Yam to give you a new one if you didn't go through the dealer?

FYI, my mileage is averaging 42 - usually less than that around town - 38 - except for this week, temps are cooler and I got... 42. I think you may be on the right track with the thermostat.

The dealer said to wait one more tank before I brought it in. Which I have now went through.
After my conversation with the "service writer" I don't have a lot of confidence with the local dealership. The tech's might be great. It's just that I like to chase my own Gremlins.

I checked the throttle position and accelerator position sensors and they are adjusted to spec. So tomorrow I will check the thermostat and install my "weather front"

 

[Buckeye56]

I reall that many folks had issues with faulty thermostats on ST1300s. As I posted before, this sure sounds like a similar condition. FWIW, once I got a hold of a dealer who understood what I was telling them, the problem was fixed by replacing the T stat. That's no guaranty that this will take care of your problem, just another data point. I hope that you will get you bike squared away and be able to enjoy it to its fullest potential!

 

[Kevhunts]

The dealer said to wait one more tank before I brought it in. Which I have now went through.
After my conversation with the "service writer" I don't have a lot of confidence with the local dealership. The tech's might be great. It's just that I like to chase my own Gremlins.

I checked the throttle position and accelerator position sensors and they are adjusted to spec. So tomorrow I will check the thermostat and install my "weather front"

You might want to pull the radiator cap, and with a cold engine on the center stand, start the bike and see if there is any movement of the coolant in the radiator. In theory, you shouldn't see much if any movement with a cold engine. This might tell you if the t-stat is stuck open.

 

[KSH]

You might want to pull the radiator cap, and with a cold engine on the center stand, start the bike and see if there is any movement of the coolant in the radiator. In theory, you shouldn't see much if any movement with a cold engine. This might tell you if the t-stat is stuck open.

Actually tomorrow I am going to get the tank loose so I can get my infrared thermometer in there for better readings. That will tell at what temp everything is moving.

 

[KSH]

Tested out the thermostat today. It is opening and closing. The best I can tell it is opening around 151 degrees.

I installed a proto-type weather front and went for a ride in 55 degree weather. The bike wanted to hold a constant 171 on the display and the instant lie-o-meter was staying around 49. This morning in light rain and 60 degree weather it was at 41.

So I think a call to the dealership to have them replace my thermostat is in order.

 

[Kevhunts]

Tested out the thermostat today. It is opening and closing. The best I can tell it is opening around 151 degrees.

I installed a proto-type weather front and went for a ride in 55 degree weather. The bike wanted to hold a constant 171 on the display and the instant lie-o-meter was staying around 49. This morning in light rain and 60 degree weather it was at 41.

So I think a call to the dealership to have them replace my thermostat is in order.

Just looking in shop manual and it states the thermostat should open between 156.2 F and 163.4 F with a full open at 183.2 F
So it appears you are close to spec. What temp does your cooling fan eventually come on at? Mine kicks on around 214 F.
Also if you are depending on the "mpg right now" display to give you accurate fuel economy, it probably won't. I saw mine swing between 23 and 99.9 mpg.
I do the math using the milage & gallons added and it's always less than the bike's avg. mpg readings.

 

[KSH]

Just looking in shop manual and it states the thermostat should open between 156.2 F and 163.4 F with a full open at 183.2 F
So it appears you are close to spec. What temp does your cooling fan eventually come on at? Mine kicks on around 214 F.
Also if you are depending on the "mpg right now" display to give you accurate fuel economy, it probably won't. I saw mine swing between 23 and 99.9 mpg.
I do the math using the milage & gallons added and it's always less than the bike's avg. mpg readings.

If you read my other posts you will see I used hand figured mpg's. I was only able to do a quick 30 mile loop. So my only gauge was the lie-o-meter.

As for the thermostat, it's 5 degrees below the low end and 12 degrees from high end of opening. That also means it could be fully open 12 degrees to soon. So after seeing how the bike likes the higher running temp of the weather front, the thermostat will be replaced.

 

[20valves]

I installed a proto-type weather front and went for a ride in 55 degree weather.

I don't understand the what you're covering up with your "weather front." It doesn't look like it covers the air inlet for the radiator. :question:

I had my bike in Colorado and rode at all different temps down to low 40's after having ridden through low 100's leaving Oklahoma and the bike returned very consistent mileage.

 

[Kevhunts]

If you read my other posts you will see I used hand figured mpg's. I was only able to do a quick 30 mile loop. So my only gauge was the lie-o-meter.

As for the thermostat, it's 5 degrees below the low end and 12 degrees from high end of opening. That also means it could be fully open 12 degrees to soon. So after seeing how the bike likes the higher running temp of the weather front, the thermostat will be replaced.

Please be sure to repost once your thermostat is replaced.
It would be benificial to all to learn the results and if you take new temperature readings for a comparison as well.