Smoke and smell from under engine: Gearheads, help!

[blackONblack]

Ok, first the symptoms:

I rode my bike to work on Friday. In the morning, I didn't notice a problem at all. On the way home, I started to notice a smell--I didn't think much of it, I figured it was a car in front of me burning something. I had previously had a coolant burning problem with a previous car, and so I recognized it as probably being coolant.

This morning, I got up and went for a ride. I was taking it for an oil change (I don't know if I'll take flack for this on this board, but I live in an apartment with an underground garage, not good conditions for changing my own oil), and I noticed the smell was still there. Immediately after the oil change, it was a really strong smell, and this time I looked down to see a decent amount of smoke coming from the bottom of the engine area.

I pulled off to take a look, and I couldn't see anything dripping, but I could tell there was smoke coming off the two pipes that (I think) funnel back into the mufflers. After some time running, the amount of smoke decreased but was still there. On the ride home, I couldn't see the smoke but at every stop light I could still smell it.

Now, some possible external factors/causes:

Temperature: This is the first week of the season where the temperature dropped below 50. On Friday, coming home, the actual starting temperature of the bike was probably lower than on my way to work, as the underground garage I keep my bike in is warmer than the covered spot I had at work (no sun, plus a high temp of about 60 degrees that day). Could the temperature be affecting some fittings that aren't expanding at the same rate, and causing a leak? I don't know if this is possible since the bike was for sure warmed up after the long rides to/from work and the bike shop.

Engine braking: I don't usually downshift to slow down, but I almost always will let off the gas sharply when I see traffic/stop lights/etc. ahead, in order to slow down before I get on the brakes. On the way out of my work parking lot, while the bike was still pretty cold, I did this in 1st/2nd gear quite a bit. During one sharp let-off, I heard a crunching sound. At the time I figured it was debris hitting some plastic or a leaf crunching under the tire. After further thought I wonder if it is related to the smoke. Could I have put too much strain on the top end/gaskets while cold? Did I bust something in the valvetrain? Something else?

Oil change: My first thought in seeing the smoke was that some extra residue from the oil change was burning off. When it continued on my way home, and I remembered the smell from the previous day, I can almost 100% rule this out. This still leaves the possibility that whatever might be loose/broken was made worse by some careless tech, but I don't think it is the original cause. Just thought I'd include this so you all know I considered it as an option.

Something else: I come from an engineering background and did some minor work on my old bike, but I am very very far from being a mechanic OR a true gearhead! It's likely that I have no idea what i'm talking about and need your help!

So, anything you all can come up with would be a VERY big help, and I'd appreciate it a whole lot. Thanks in advance!

 

[RJ2112]

Ok, first the symptoms:

I rode my bike to work on Friday. In the morning, I didn't notice a problem at all. On the way home, I started to notice a smell--I didn't think much of it, I figured it was a car in front of me burning something. I had previously had a coolant burning problem with a previous car, and so I recognized it as probably being coolant.

This morning, I got up and went for a ride. I was taking it for an oil change (I don't know if I'll take flack for this on this board, but I live in an apartment with an underground garage, not good conditions for changing my own oil), and I noticed the smell was still there. Immediately after the oil change, it was a really strong smell, and this time I looked down to see a decent amount of smoke coming from the bottom of the engine area.

I pulled off to take a look, and I couldn't see anything dripping, but I could tell there was smoke coming off the two pipes that (I think) funnel back into the mufflers. After some time running, the amount of smoke decreased but was still there. On the ride home, I couldn't see the smoke but at every stop light I could still smell it.

Now, some possible external factors/causes:

Temperature: This is the first week of the season where the temperature dropped below 50. On Friday, coming home, the actual starting temperature of the bike was probably lower than on my way to work, as the underground garage I keep my bike in is warmer than the covered spot I had at work (no sun, plus a high temp of about 60 degrees that day). Could the temperature be affecting some fittings that aren't expanding at the same rate, and causing a leak? I don't know if this is possible since the bike was for sure warmed up after the long rides to/from work and the bike shop.

Engine braking: I don't usually downshift to slow down, but I almost always will let off the gas sharply when I see traffic/stop lights/etc. ahead, in order to slow down before I get on the brakes. On the way out of my work parking lot, while the bike was still pretty cold, I did this in 1st/2nd gear quite a bit. During one sharp let-off, I heard a crunching sound. At the time I figured it was debris hitting some plastic or a leaf crunching under the tire. After further thought I wonder if it is related to the smoke. Could I have put too much strain on the top end/gaskets while cold? Did I bust something in the valvetrain? Something else?

Oil change: My first thought in seeing the smoke was that some extra residue from the oil change was burning off. When it continued on my way home, and I remembered the smell from the previous day, I can almost 100% rule this out. This still leaves the possibility that whatever might be loose/broken was made worse by some careless tech, but I don't think it is the original cause. Just thought I'd include this so you all know I considered it as an option.

Something else: I come from an engineering background and did some minor work on my old bike, but I am very very far from being a mechanic OR a true gearhead! It's likely that I have no idea what i'm talking about and need your help!

So, anything you all can come up with would be a VERY big help, and I'd appreciate it a whole lot. Thanks in advance!

My first guess is that you flicked something onto your headers from the roadway. If you had damaged something serious, the bike would have seized up by now. If it's road tar, or someone else's engine/transmission/ooky sh*t that is now melting off your pipes, you'll smell it for a while.

Keep an eye on engine temps... if they remain stable, it's almost certainly nothing to get concerned about. (If your bike is 2007 or later, you should probably check to ensure the electric fan on the radiator spins freely as a precaution.)

 

[blackONblack]

My first guess is that you flicked something onto your headers from the roadway. If you had damaged something serious, the bike would have seized up by now. If it's road tar, or someone else's engine/transmission/ooky sh*t that is now melting off your pipes, you'll smell it for a while.

Keep an eye on engine temps... if they remain stable, it's almost certainly nothing to get concerned about. (If your bike is 2007 or later, you should probably check to ensure the electric fan on the radiator spins freely as a precaution.)

Thanks a bunch. This reminded me that I flung a TON of those bits of tar from road work up under the bike on my way out this morning--2 out of 1 lanes were closed for some major work that just started this morning.

Thanks for the tip on the fan, I'll check it out next time I start up the bike. I was also thinking of getting some coolant to take with me when I'm on the road in case it does end up being the problem.

Thanks again. Still would love to hear other thoughts if anyone has any.

 

[ChevyFazer]

I tend to lube my chain fairly heavy and the chain lube can also get flung on the exhaust creating those effects

 

[blackONblack]

Looks like I found the culprit. I was about to go for a ride today to see if whatever was on the headers would burn off completely or if it would continue to smoke. When I checked the coolant, I noticed it was low, and the reservoir cap was off/loose. I'm guessing the cap popped off and spewed some fluid, some of which got to the headers. As I continued to ride, it probably continued to spray a little, which would explain the smell remaining throughout the ride.

Now this raises another question: What type of coolant should I use? I tried to look up what color is what type on the internet, but that resulted in a "it depends on the brand" answer. As far as I can tell, the color is green (but I'll take a flashlight with me next time so I can be sure), but I don't know what that means. Anyone know what coolant it comes with from the factory? The manual is no help. I don't want to damage the cooling system, as I have heard that mixing propylene glycol and ethyl glycol can cause a reaction. Is this the case?

Again, thanks in advance for your answers! Your comments have been really helpful.

 

[PosterFZ6]

Looks like I found the culprit. I was about to go for a ride today to see if whatever was on the headers would burn off completely or if it would continue to smoke. When I checked the coolant, I noticed it was low, and the reservoir cap was off/loose. I'm guessing the cap popped off and spewed some fluid, some of which got to the headers. As I continued to ride, it probably continued to spray a little, which would explain the smell remaining throughout the ride.

Now this raises another question: What type of coolant should I use? I tried to look up what color is what type on the internet, but that resulted in a "it depends on the brand" answer. As far as I can tell, the color is green (but I'll take a flashlight with me next time so I can be sure), but I don't know what that means. Anyone know what coolant it comes with from the factory? The manual is no help. I don't want to damage the cooling system, as I have heard that mixing propylene glycol and ethyl glycol can cause a reaction. Is this the case?

Again, thanks in advance for your answers! Your comments have been really helpful.

Just flush the whole cooling system and replace it with new coolant fluid.

I think for the summer the ratio was 50:50 coolant and distilled water.

For winter it might be 30:70 water and coolant.

 

[blackONblack]

Just flush the whole cooling system and replace it with new coolant fluid.

I think for the summer the ratio was 50:50 coolant and distilled water.

For winter it might be 30:70 water and coolant.

I take this to mean that yes, mixing the two types of coolant is bad? If so I guess I have no choice, and according to the manual, changing the coolant doesn't seem that hard, and it does have the recommended antifreeze (ethylene glycol, 1:1 ratio with water).

 

[iSteve]

Just buy one of the motorcycle specific coolant/antifreeze that come premixed. Your bike will love you for it and you don't have to worry about mixing.

 

[blackONblack]

Just buy one of the motorcycle specific coolant/antifreeze that come premixed. Your bike will love you for it and you don't have to worry about mixing.

I was referring more to the potential for accidentally adding a different type when I am topping up, rather than mixing the coolant mixture.

 

[iSteve]

Almost all the the motorcycle specific coolants are compatible with stock motorcycle coolants. And if you empty and flush the old stuff you won't have any problems anyway.

 

[TownsendsFJR1300]

Most of the on the shelf anti-freeze do mix with the others. The manual does call for ethyl glycol (page 3-19 Yamaha manual). I try to change mine every two years and have been using Preston 50/50 premix, you can't screw up the %'s. The manual does call for 1:1 BTW. If your anti-freeze is old, you will see a difference in your riding temps, not alot, but some..

BTW, I did call Yamaha headquarters a couple of years ago to see what type of anti-freeze they put in the bike as it was a different colored green (original anti-freeze). They couldn't tell me, I'm sure its something from Japan as it'd be the most convenient .

Its pretty simple to change the anti-freeze yourself.

There's one bolt on the right side of the bike at the bottom of the water pump (there's a large hose that goes to it). The bolt is an 8mm head with a COPPER WASHER under it. Remove that bolt, theres a retainer at the radiator cap (one bolt and a retainer) and the cap comes off...

As for the overflow tank, two bolts and its off. It is somewhat difficult to see the level in the tank but pulling the rubber cap off and peeking in with a flashlight seems to help. The overflow from that tank does dump thru a hose just above the header so try not to over fill it..

I run mine, get it hot and let it cool down. Top off again and your done.

 

[NorcoT]

Those pipes are shiny!

Glad you found the cause of the smoking, I had a similar worry a while back but figured out it was the corroion protective spray I was using clings to the headers and smokes like crazy for a while.