engine temp question

[jts6yf]

Now this might be a silly thing to bring up but I was researching ways to improve mpg figures and I stumbled upon someone suggesting to block the radiator during cold weather. After I thought about it some more, I do remember seeing semis on the highway entirely blocking the front of their trucks. How is this supposed to help? Has anyone tried it?

 

[iSteve]

This will only help if your engine never gets up to operating temp. If the engine doesn't warm up it will stay in start mode kind of like a choke on a carburetor.

 

[jts6yf]

Well then wouldnt this defeat the purpose of them driving like this on the highway? I mean those guys almost never shut their trucks off so it wouldnt be beneficial for getting them to the initial operating temp.

 

[yamihoe]

remember the cooling system on a semi is literally +20x the size of ours. They tow, and are boosted, creating alot more heat, BUT when they arent FULLY loaded (maxed out on the DOT scales) that extra cooling capacity is a hindrance.

 

[TownsendsFJR1300]

Now this might be a silly thing to bring up but I was researching ways to improve mpg figures and I stumbled upon someone suggesting to block the radiator during cold weather. After I thought about it some more, I do remember seeing semis on the highway entirely blocking the front of their trucks. How is this supposed to help? Has anyone tried it?

The thermostat on your bike shouldn't open until the engines within a certain temp range. It should also close/adjust as needed to keep the engine temp within those parameters. It'll also come out of the "choke" mode (richer mixture) once at a certain temp.

The oil will take a little longer to warm and will be slightly thicker than summertime weather/temps.

With the cooler temps down here, my 07 coolant runs about 168F not in heavy traffic, got up to 188F in heavy traffic, about 82F outside...

You could try a piece of cardboard covering up 1/3-1/2 of the radiator and monitor how it runs (I would keep the area of the fan OPEN). :thumbup:

 

[pookamatic]

Well then wouldnt this defeat the purpose of them driving like this on the highway? I mean those guys almost never shut their trucks off so it wouldnt be beneficial for getting them to the initial operating temp.

These are diesel engines, which naturally run much cooler than standard gasoline engines because they give off less waste heat. If they don't block a portion of the radiator in certain situations (very cold, no load, lots of highway), the engine would be too cold to run properly/efficiently.

 

[Dresnewtoy]

+1. Diesel engines are a whole different beast. I'm not in favour of doing anything to impact the proper cooling of your motorcycle engine. A few more mpgs can be had by changing your riding technique (if you're not already doing that) - shift a little earlier, use the throttle a little less, coast down to a stop, etc., etc.,..:thumbup:

 

[dpaul007]

It's winter, you will always get worse gas mileage, nothing you can do about it short of heating the air that's entering your engine. Colder air is denser air, therefor requiring more fuel to keep the AFR in check.

 

[fb40dash5]

These are diesel engines, which naturally run much cooler than standard gasoline engines because they give off less waste heat. If they don't block a portion of the radiator in certain situations (very cold, no load, lots of highway), the engine would be too cold to run properly/efficiently.

And trucks typically have a much bigger radiator to put up with hot summer temps. I drove diesel Penske moving truck cross country in the winter of '09. It was -20F going across IL and IA... I cut a tarp and put it over the radiator, the needle STILL didn't budge off the cold mark. I was freezing my *** off in a coat, hat and gloves in that thing. Oh, and it got a wonderful 4.5mpg doing it, too. Yay.

It's winter, you will always get worse gas mileage, nothing you can do about it short of heating the air that's entering your engine. Colder air is denser air, therefor requiring more fuel to keep the AFR in check.

Yep, no getting around it, I really doubt covering the radiator will help unless the tach bar never stops blinking. Or whatever the equivalent is on the S2. I use Fuelly, and could probably make an average temp graph off the graph of my mileage. I can get low 50s in the summer without much trouble, but when it's close to freezing I can't get above about 42.

 

[jts6yf]

I rode for 2 hours on the highway today (25*F) and the temperature never got over 149F.

 

[TownsendsFJR1300]

I rode for 2 hours on the highway today (25*F) and the temperature never got over 149F.

I thought about it some more.

Does your bike take a long time to warm up to the 149F?

If its taking unusually long, its very possible your thermostat is stuck open. The water keeps flowing thru the radiator and never warms fully. It should stay closed until the engine gets to temp(which is above 149F). Page 6-7, per the 07 Yamaha manual, it should open at 160F.

What shape/maintainance wise is your coolant system in? Has the coolant be changed on a regular basis?


Any other cold riders, please chime in...

 

[jts6yf]

I have to look into that. I have had the bike 11 months and i havnt changed the coolant yet. Is it not possible that because this is a naked bike, the air could be cold enough to whisk heat away that quickly?

 

[pookamatic]

I think my tstat may be stuck open. Haven't checked the coolant but the PO said it was replaced 2 years ago.

Still, if the tstat was closed, I should see nearly no drop in engine temp while moving while the engine is under 149. Yet, if I get going from a cold start when it reads 125, the temps will drop down to 110 or so.

 

[TownsendsFJR1300]

I have to look into that. I have had the bike 11 months and i havnt changed the coolant yet. Is it not possible that because this is a naked bike, the air could be cold enough to whisk heat away that quickly?

The radiator is in the same place as a faired version, that alone wouldn't make a difference.

The thermostat is designed to stay closed until the water temp in the engine reaches 160F (I'd give or take a couple of degree's). With 25F outside (plus wind chill, especially while under way), the thermostat should be partially closing to keep the temperature of the engine to at least 160F.

"Over cooling", page 9-3 in the 07 Yamaha shop manual quote "Thermostat" *thermostat stays open.

You should be able to start the bike cold as usual, just let it idle and watch the temp gauge rise steadily until 160F. Depending on your climate, I would think 10 minutes idleing would bring it up to full temp.

If the temp gauge stays low and never climbs, it re-inforces that the thermostat is likely open letting the coolant flow to the radiator, thus never heating the coolant fully.

Unfortunatly, the thermostat is located below the throttle bodies at the rear of the engine cylinder. The manual calls for removing the TB's (and everything else before that). You can see a large coolant hose wrap around the left side of the bike to the rear of the cylinder. The thermostat is under the housing (two bolts hold the housing) that hose connects to. I've never had to change the thermostat out on the FZ6, you can see the bolts but its super tight with the TB's in place..

I'll send you a PM...

 

[TownsendsFJR1300]

I think my tstat may be stuck open. Haven't checked the coolant but the PO said it was replaced 2 years ago.

Still, if the tstat was closed, I should see nearly no drop in engine temp while moving while the engine is under 149. Yet, if I get going from a cold start when it reads 125, the temps will drop down to 110 or so.

Correct, its stuck open, NOT closed... If it was closed, it wouldn't cool and just continue to heat.

With the thermostat open all the time, the bike never fully gets to temp and cools down with the outside conditions. The thermostat, stuck open, isn't keeping the coolant in the engine long enough to get hot..

 

[pookamatic]

It may be stuck in a partial position because it does heat up and in my limited opinion, gets hot too quickly in traffic. Regardless, I'll be replacing it when I change out the coolant.