Why is motorcycle exhaust so excessive?

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Subyman

Moderator <br> VC&G Forum
Mar 18, 2005
7,876
32
86
Muse must have smelled a poorly running motorcycle and then attributed it to all motorcycles or something. I used to ride them and I see them all the time and have never noticed a smell. Diesel and old cars are the only vehicles I can smell.
 

Greenman

Lifer
Oct 15, 1999
21,852
6,234
136
If you're talking about Harley's, it's because almost everyone has them tuned for power, which causes increased emissions, and lowers engine temps. The stock tune on most newer bikes is lean, which is good for the air, bad for the rider. A rich tune lowers engine temps, and increases mid range horsepower. It also sounds better if you happen to have an after market exhaust.
 

Charlie98

Diamond Member
Nov 6, 2011
6,298
64
91
OK, I'll bite ... in what way does ethanol make the fuel burn less efficiently? Ethanol has a third less energy by volume than gasoline and E10 will results in a reduction in fuel mileage of about 3.4% -- right in line with it's lower energy content.

On the upside ... ethanol in the gas pretty much ensures that there's no water in the tank as ethanol is a water getter. Also, cars running ethanol have more power without doing any modifications owing to the oxygenated nature of ethanol. Finally, ethanol is much cleaner than gasoline and helps the pollution numbers for gasoline with ethanol.

But, I'm not surprised that an oil state resident would be bad mouthing ethanol just as residents from the corn belt tend to be a overly happy about ethanol.

Brian

Ethanol has less energy potential than gasoline... you need more of it, volume wise, to produce the same energy. I guess you can split hairs about the 'efficiency' of the burn, I'm talking about the overall efficiency of blended gas vs straight gas.

Ethanol absorbs water... that's true, but not in a good way. It absorbs water in the fuel, it absorbs water out of the air. If it absorbs enough water, it will separate from the gas (phase separation) and cause problems. This has happened not only in cars, but in storage tanks as well. When a storage tank of blended fuel separates, you have to pump it completely dry (and I'm not talking about the bottom 3", I'm talking vac'ing it completely empty) and junk the fuel. Ethanol blended fuel causes corrosion issues; personally, it destroyed my carburetor (the O-rings, primarily) on one of my motorcycles, and is not recommended for pretty much anything besides passenger vehicles and light trucks. There are other problems with plastic fuel tanks and fuel system parts. It is not used in aviation or marine applications... there's a reason for that.

Not only am I an oil state resident, I worked in the fuel storage and delivery industry for 8 years, my wife for 17. You think you are being clever by dismissing my comments because I live in an 'oil state?' How about the whole 'Big Corn' industry that pushed ethanol in the first place? I dare you to follow the money on that one.

Ethanol fuels are a pain in the ass from start to finish. Production, transport and pipeline, storage, blending at the loading rack, and then issues at the retail point and, finally, the end user.
 

Muse

Lifer
Jul 11, 2001
40,211
9,817
136
Muse must have smelled a poorly running motorcycle and then attributed it to all motorcycles or something. I used to ride them and I see them all the time and have never noticed a smell. Diesel and old cars are the only vehicles I can smell.
Well, I've had my eyes tested, my ears too, but AFAIK there aren't any sense-of-smell tests, but yes, I feel I have a good sense of smell. I'm not imagining these things, and I'm not jumping to conclusions because one or two or a handful of 2 wheeled motorized vehicles have bothered me. I'm sure that many other people would endorse my comments. Here, of course, a disproportionate contribution is from motorcycle enthusiasts, several of them (I assume they are in that class) accusing me of being nothing more than a troublemaker.

I have not said a word about noise, several others have. I am very aware of the blight of noise pollution but obviously one gets over that quickly unless it's so loud as to damage your hearing. Air pollution is more irritating and serious in general because it can foul your lungs, blood stream, and your organs, and of course it contributes to air pollution and it's myriad complex negative impact on the environment.
 

marincounty

Diamond Member
Nov 16, 2005
3,227
5
76
Hey, don't take my word for it:
. Seems to me that the great majority are putting out a whole lot of pollutants compared to the great majority of cars, at least where I live (Berkeley, CA).

I'm not a kill-joy, if you guys enjoy your bikes, love your bikes, more power to you. If there's anything you can do to lessen the pollution, well, I think (suppose) you should.
I lived in Berkeley for many years, and I say BS.
I lived across the street from a motorcycle parking area, and never was bothered by exhaust fumes. I might have been woken up by someone's loud exhaust- I'm looking at you Ducati rider, but never bothered by fumes.
On the other hand, I had vile diesel fumes waft in through my windows many times due to my living on a busy street, and the horrible polluting AC Transit buses.
When the state banned two-strokes, they should have also banned all diesel vehicles from the street.
 

SparkyJJO

Lifer
May 16, 2002
13,357
7
81
I lived in Berkeley for many years, and I say BS.
I lived across the street from a motorcycle parking area, and never was bothered by exhaust fumes. I might have been woken up by someone's loud exhaust- I'm looking at you Ducati rider, but never bothered by fumes.
On the other hand, I had vile diesel fumes waft in through my windows many times due to my living on a busy street, and the horrible polluting AC Transit buses.
When the state banned two-strokes, they should have also banned all diesel vehicles from the street.

lol sure.

How would you get cargo moved about? Deliveries to stock store shelves etc?

Apparently you didn't think that one through.
 

Brian Stirling

Diamond Member
Feb 7, 2010
3,964
2
0
Ethanol has less energy potential than gasoline... you need more of it, volume wise, to produce the same energy. I guess you can split hairs about the 'efficiency' of the burn, I'm talking about the overall efficiency of blended gas vs straight gas.

Ethanol absorbs water... that's true, but not in a good way. It absorbs water in the fuel, it absorbs water out of the air. If it absorbs enough water, it will separate from the gas (phase separation) and cause problems. This has happened not only in cars, but in storage tanks as well. When a storage tank of blended fuel separates, you have to pump it completely dry (and I'm not talking about the bottom 3", I'm talking vac'ing it completely empty) and junk the fuel. Ethanol blended fuel causes corrosion issues; personally, it destroyed my carburetor (the O-rings, primarily) on one of my motorcycles, and is not recommended for pretty much anything besides passenger vehicles and light trucks. There are other problems with plastic fuel tanks and fuel system parts. It is not used in aviation or marine applications... there's a reason for that.

Not only am I an oil state resident, I worked in the fuel storage and delivery industry for 8 years, my wife for 17. You think you are being clever by dismissing my comments because I live in an 'oil state?' How about the whole 'Big Corn' industry that pushed ethanol in the first place? I dare you to follow the money on that one.

Ethanol fuels are a pain in the ass from start to finish. Production, transport and pipeline, storage, blending at the loading rack, and then issues at the retail point and, finally, the end user.

Apparently you didn't actually read my post so let me correct you on a few items...

First, I did make the comment about corn state folks over doing the value of ethanol -- it's right in my post if you'd bothered to read it. And yes, you can bet money is part of the equation as farmers have a surprising amount of clout.

Second, yep, ethanol pulls water as it's a getter, but the upside in that by doing so it makes sure there is none in your cars tank. And yes, it can pull moisture from the air, but in the cars tank you do NOT have air circulating in a way that brings tons of water in -- tanks are EQUALIZED but the air in the tank is not circulated from the outside so the net inflow of water, even in VERY humid areas is actually quite limited. That large storage tanks may have some issues is not terribly surprising as they aren't going to spend a penny keeping moisture out and would rather complain about getting water in the tanks. Why spend money using dry nitrogen when you can just bitch about them corn folk forcing this on ya?

Older vehicles may well have some problems with corrosion and I guess if you're still running carbs your best bet would be to get E0 gas and you can generally find that if you look. Are you saying E0 gas isn't available in Texas? There were similar problems associated with the switch from leaded fuels to unleaded fuels as I'm sure you remember...

In summary: E10 provides MORE power but less mileage, burns cleaner with fewer emissions, raises octane permitting the use of lower spec gasoline, is a renewable fuel source, and yes, it does provide additional jobs in the corn belt.


Brian
 

Charlie98

Diamond Member
Nov 6, 2011
6,298
64
91
Apparently you didn't actually read my post so let me correct you on a few items...

First, I did make the comment about corn state folks over doing the value of ethanol -- it's right in my post if you'd bothered to read it. And yes, you can bet money is part of the equation as farmers have a surprising amount of clout.

Second, yep, ethanol pulls water as it's a getter, but the upside in that by doing so it makes sure there is none in your cars tank. And yes, it can pull moisture from the air, but in the cars tank you do NOT have air circulating in a way that brings tons of water in -- tanks are EQUALIZED but the air in the tank is not circulated from the outside so the net inflow of water, even in VERY humid areas is actually quite limited. That large storage tanks may have some issues is not terribly surprising as they aren't going to spend a penny keeping moisture out and would rather complain about getting water in the tanks. Why spend money using dry nitrogen when you can just bitch about them corn folk forcing this on ya?

Older vehicles may well have some problems with corrosion and I guess if you're still running carbs your best bet would be to get E0 gas and you can generally find that if you look. Are you saying E0 gas isn't available in Texas? There were similar problems associated with the switch from leaded fuels to unleaded fuels as I'm sure you remember...

In summary: E10 provides MORE power but less mileage, burns cleaner with fewer emissions, raises octane permitting the use of lower spec gasoline, is a renewable fuel source, and yes, it does provide additional jobs in the corn belt.


Brian

No, I did read your post... and you are contradicting yourself. Ethanol has less energy potential than gasoline... there is no way E10 can provide MORE power (given the same volume of fuel in each instance.) You have to use more E10 fuel to equal the same energy output as straight gasoline.

It does burn cleaner in some circumstances (given the same volume of fuel in each instance,) but requires, again... more E10 to equal the same energy output as straight gasoline. Furthermore, as ethanol absorbs water, it quickly breaks down and delivers lower octane numbers (and the aforementioned phase separation if it continues) and there are other instances where it can produce higher emissions.

Just FYI... gasoline and ethanol are mixed as they are loaded on the transport truck. Ethanol is stored separately, for obvious reasons. I'm not familiar with storage requirements, but I'm sure there are some steps taken to keep water contamination from occurring prior to loading to final delivery. Water will readily separate from fuel in storage and is not an issue.

Retail storage. It would be absurdly unworkable to build and maintain a closed-loop in-ground storage system. As the fuel is pumped out, some amount of vapor is returned to the storage tank (from the vehicle being fueled) but differences in temperatures, poor maintenance, and even just water setting in the parking lot over the fills allows moisture to enter the storage tanks... it is, quite literally, impossible to keep water from entering the retail storage tanks... and this is the most critical point.... before it is pumped into a vehicle. With normal gas, water will settle out to the bottom of the tank; with ethanol, it is absorbed and delivered to the consumer.

Although I see non-E fuel for sale in OK and AR, I can't find it here in TX; I live in one of the emission control areas of TX, before the days of E10, we had 'reformulated' gasoline (vs 'conventional' fuel sold outside the 'VOC' areas of Dallas, Houston, and other munis) and, further, winter and summer blends. Reformulated fuel (RFG) produced less fuel economy, winter blend even more so, and now we have E10... which, again, decreases fuel economy. It may be available out in Nowheresville, but I don't regularly venture there, and as the storage facilities are forced to supply a larger and larger VOC restrictive area, they are simply phasing out conventional gas storage in favor of straight up RFG and ethanol.

My point is, and this is just my .02 worth based on my experiences, both professionally and personally, ethanol fuel is just bad, bad, bad. It adds additional costs to the whole fuel delivery and storage processes, can produce substandard performance vs straight gasoline, increases maintenance problems vs straight gasoline, for what I see is very little benefit.... and every bit of that cost is passed on to the consumer.

EDIT: And, I forgot the biggest problem... ethanol can't be pipelined... it must be trucked, 9000 gallons at a time, from the source to the storage terminal. How much fuel do you suppose it takes to truck in all that ethanol? OTR trucks get around 5-6MPG. Factor in all the wear and tear on the trucks, the cost of maintenance, the wear on the roads, etc...

I'll have to do some research... I'm curious to see what the numbers are of just straight-up conventional gas vs full-on RFG E10... in the end, I'll bet it's a wash.
 
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Meghan54

Lifer
Oct 18, 2009
11,684
5,225
136
Ethanol absorbs water... that's true, but not in a good way. It absorbs water in the fuel, it absorbs water out of the air.


The contention that ethanol grabs water out of the air is bullshit. Please link any scientific paper that shows that.

I can show when the engineers at Mercury outboards specifically noted that ethanol has no mechanism to pull water out of the air.....doesn't happen.

In fact, here's the slide from a seminar Mercury Marine put on in Aug. 2011 which states this:

water-ethanol-mercury.slide.jpg




Now, you'd think Mercury Marine, the largest outboard manufacturer in the U.S. a company that's fought against ethanol use in outboards since like forever, would get their facts straight. And they did, as shown above, instead of repeating a nonsense myth non-stop.



Here's a link to a copy of the seminar, noted above:

http://dcd96xmek71bc.cloudfront.net...atingIndustry/MythsofEthanol-August252011.mp4
 
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Muse

Lifer
Jul 11, 2001
40,211
9,817
136
I lived in Berkeley for many years, and I say BS.

Oh, so you say I'm making this up, with nefarious intent. :eek: YTF would I do that? I smell it. Obviously my smeller's a lot better than yours. I will not apologize for being more sensitive than you or anyone else. I smell that shit, damn it. And yes, it bothers me... a lot! A lot of times I smell it with cars, but that's very much the exception. With motorcycles, in the great majority of cases for sure when I catch some of the exhaust.
 
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Torn Mind

Lifer
Nov 25, 2012
12,024
2,757
136
The contention that ethanol grabs water out of the air is bullshit. Please link any scientific paper that shows that.

I can show when the engineers at Mercury outboards specifically noted that ethanol has no mechanism to pull water out of the air.....doesn't happen.

In fact, here's the slide from a seminar Mercury Marine put on in Aug. 2011 which states this:

water-ethanol-mercury.slide.jpg




Now, you'd think Mercury Marine, the largest outboard manufacturer in the U.S. a company that's fought against ethanol use in outboards since like forever, would get their facts straight. And they did, as shown above, instead of repeating a nonsense myth non-stop.



Here's a link to a copy of the seminar, noted above:

http://dcd96xmek71bc.cloudfront.net...atingIndustry/MythsofEthanol-August252011.mp4
They are contradicting themselves with poorly worded slides.

It does not say ethanol will not absorb water from the air. Their is that the amounts absorbed is insignificant to matter.Insignificant implies something is occuring, but not enough to make a difference for the application at hand. The term "active transfer mechanism" doesn't mean anything, since absorption is a passive process. The gas sits there. There air sits there. The transfer occurs as random water vapor moleclues are near the ethanol and by chemical atttraction, the water is indeed absorbed by the ethanol in the fuel mix.

It's not different from letting a piece of steel rust. There is not "active mechanism"(whatever that means) making the water vapor touch the steel. But it is in the air and the few molecules that come in contact with the metal begins to rusting process.
 

JulesMaximus

No Lifer
Jul 3, 2003
74,544
924
126
Bikes are definitely more polluting than cars but this has changed in the past few years. Just a half dozen or so years ago motorcycles didn't even need catalytic converters but now they do. Still, many riders scrap the stock exhaust in favor of something louder and these exhausts frequently do not have the heavy cat so most bikes don't have the pollution controls of modern cars.
 

Brian Stirling

Diamond Member
Feb 7, 2010
3,964
2
0
No, I did read your post... and you are contradicting yourself. Ethanol has less energy potential than gasoline... there is no way E10 can provide MORE power (given the same volume of fuel in each instance.) You have to use more E10 fuel to equal the same energy output as straight gasoline.

It does burn cleaner in some circumstances (given the same volume of fuel in each instance,) but requires, again... more E10 to equal the same energy output as straight gasoline. Furthermore, as ethanol absorbs water, it quickly breaks down and delivers lower octane numbers (and the aforementioned phase separation if it continues) and there are other instances where it can produce higher emissions.

Just FYI... gasoline and ethanol are mixed as they are loaded on the transport truck. Ethanol is stored separately, for obvious reasons. I'm not familiar with storage requirements, but I'm sure there are some steps taken to keep water contamination from occurring prior to loading to final delivery. Water will readily separate from fuel in storage and is not an issue.

Retail storage. It would be absurdly unworkable to build and maintain a closed-loop in-ground storage system. As the fuel is pumped out, some amount of vapor is returned to the storage tank (from the vehicle being fueled) but differences in temperatures, poor maintenance, and even just water setting in the parking lot over the fills allows moisture to enter the storage tanks... it is, quite literally, impossible to keep water from entering the retail storage tanks... and this is the most critical point.... before it is pumped into a vehicle. With normal gas, water will settle out to the bottom of the tank; with ethanol, it is absorbed and delivered to the consumer.

Although I see non-E fuel for sale in OK and AR, I can't find it here in TX; I live in one of the emission control areas of TX, before the days of E10, we had 'reformulated' gasoline (vs 'conventional' fuel sold outside the 'VOC' areas of Dallas, Houston, and other munis) and, further, winter and summer blends. Reformulated fuel (RFG) produced less fuel economy, winter blend even more so, and now we have E10... which, again, decreases fuel economy. It may be available out in Nowheresville, but I don't regularly venture there, and as the storage facilities are forced to supply a larger and larger VOC restrictive area, they are simply phasing out conventional gas storage in favor of straight up RFG and ethanol.

My point is, and this is just my .02 worth based on my experiences, both professionally and personally, ethanol fuel is just bad, bad, bad. It adds additional costs to the whole fuel delivery and storage processes, can produce substandard performance vs straight gasoline, increases maintenance problems vs straight gasoline, for what I see is very little benefit.... and every bit of that cost is passed on to the consumer.

EDIT: And, I forgot the biggest problem... ethanol can't be pipelined... it must be trucked, 9000 gallons at a time, from the source to the storage terminal. How much fuel do you suppose it takes to truck in all that ethanol? OTR trucks get around 5-6MPG. Factor in all the wear and tear on the trucks, the cost of maintenance, the wear on the roads, etc...

I'll have to do some research... I'm curious to see what the numbers are of just straight-up conventional gas vs full-on RFG E10... in the end, I'll bet it's a wash.

I'll restate the FACTS ... gasoline with ethanol has less energy than pure gasoline but does absolutely produce more power. And again, if you'd bothered to read, I mean actually read, what I'd written I stated that ethanol contains oxygen and you get more power because it's like having a slightly more dense air charge in the cylinder. Yes, you need more fuel to get more power but you get more power -- FACT!

Most ethanol is transported by train! Where I live in Utah we have hundreds of oil trucks transporting crude to the refineries -- so, yeah, transporting oil eats gas to.

Ethanol is bad for the oil industry, you got that right, but it is good for the farmers and is a RENEWABLE energy source -- the carbon it emits when burned is reclaimed when grown so has a nearly net zero carbon footprint. Can oil say that?


Brian
 

jlee

Lifer
Sep 12, 2001
48,518
223
106
No, I did read your post... and you are contradicting yourself. Ethanol has less energy potential than gasoline... there is no way E10 can provide MORE power (given the same volume of fuel in each instance.) You have to use more E10 fuel to equal the same energy output as straight gasoline.

It does burn cleaner in some circumstances (given the same volume of fuel in each instance,) but requires, again... more E10 to equal the same energy output as straight gasoline. Furthermore, as ethanol absorbs water, it quickly breaks down and delivers lower octane numbers (and the aforementioned phase separation if it continues) and there are other instances where it can produce higher emissions.

Just FYI... gasoline and ethanol are mixed as they are loaded on the transport truck. Ethanol is stored separately, for obvious reasons. I'm not familiar with storage requirements, but I'm sure there are some steps taken to keep water contamination from occurring prior to loading to final delivery. Water will readily separate from fuel in storage and is not an issue.

Retail storage. It would be absurdly unworkable to build and maintain a closed-loop in-ground storage system. As the fuel is pumped out, some amount of vapor is returned to the storage tank (from the vehicle being fueled) but differences in temperatures, poor maintenance, and even just water setting in the parking lot over the fills allows moisture to enter the storage tanks... it is, quite literally, impossible to keep water from entering the retail storage tanks... and this is the most critical point.... before it is pumped into a vehicle. With normal gas, water will settle out to the bottom of the tank; with ethanol, it is absorbed and delivered to the consumer.

Although I see non-E fuel for sale in OK and AR, I can't find it here in TX; I live in one of the emission control areas of TX, before the days of E10, we had 'reformulated' gasoline (vs 'conventional' fuel sold outside the 'VOC' areas of Dallas, Houston, and other munis) and, further, winter and summer blends. Reformulated fuel (RFG) produced less fuel economy, winter blend even more so, and now we have E10... which, again, decreases fuel economy. It may be available out in Nowheresville, but I don't regularly venture there, and as the storage facilities are forced to supply a larger and larger VOC restrictive area, they are simply phasing out conventional gas storage in favor of straight up RFG and ethanol.

My point is, and this is just my .02 worth based on my experiences, both professionally and personally, ethanol fuel is just bad, bad, bad. It adds additional costs to the whole fuel delivery and storage processes, can produce substandard performance vs straight gasoline, increases maintenance problems vs straight gasoline, for what I see is very little benefit.... and every bit of that cost is passed on to the consumer.

EDIT: And, I forgot the biggest problem... ethanol can't be pipelined... it must be trucked, 9000 gallons at a time, from the source to the storage terminal. How much fuel do you suppose it takes to truck in all that ethanol? OTR trucks get around 5-6MPG. Factor in all the wear and tear on the trucks, the cost of maintenance, the wear on the roads, etc...

I'll have to do some research... I'm curious to see what the numbers are of just straight-up conventional gas vs full-on RFG E10... in the end, I'll bet it's a wash.

I can tell you what the (power) numbers are of E10 vs E85 in about a week... :p
 

WT

Diamond Member
Sep 21, 2000
4,816
59
91
I personally like the smell of race gas coming from a 2 stroke on the trails here in PA. You can always tell when someones running a classic ATV in the woods like a Banshee or 250R just by the sweet smell of the exhaust.
Can't say the same about a diesel truck that I'm following on the highway.
 

jdoggg12

Platinum Member
Aug 20, 2005
2,685
11
81
Oh, so you say I'm making this up, with nefarious intent. :eek: YTF would I do that? I smell it. Obviously my smeller's a lot better than yours. I will not apologize for being more sensitive than you or anyone else. I smell that shit, damn it. And yes, it bothers me... a lot! A lot of times I smell it with cars, but that's very much the exception. With motorcycles, in the great majority of cases for sure when I catch some of the exhaust.
This whole thread is starting to remind me of something, haha

spaceblanket.jpg
 

freeskier93

Senior member
Apr 17, 2015
487
19
81
No, I did read your post... and you are contradicting yourself. Ethanol has less energy potential than gasoline... there is no way E10 can provide MORE power (given the same volume of fuel in each instance.) You have to use more E10 fuel to equal the same energy output as straight gasoline.

Power is the rate at which energy is produced for a unit of time. Ethanol absolutely can produce more power than gasoline, it just means that the ethanol will be consumed at a higher rate.
 
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RLGL

Platinum Member
Jan 8, 2013
2,114
321
126
1.
After being in the marine industry and changing water separating fuel filters on the stern drive engines for years, I found that 99% of the filters had NO water in them. With the remaining 1% an external source could be found.
2.
As far as the noise mentioned in the first post: The back pressure from a muffler will rob the power from the engine. That is the only reason.
 

Z15CAM

Platinum Member
Nov 20, 2010
2,184
64
91
www.flickr.com
2 into 1 or 4 into 1 - You gotta play with the Jets.

Personally over any 2 Cyl. I would choose an old 3 Cyl Lavenda Breganze to race with.
 
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Greenman

Lifer
Oct 15, 1999
21,852
6,234
136
Oh, so you say I'm making this up, with nefarious intent. :eek: YTF would I do that? I smell it. Obviously my smeller's a lot better than yours. I will not apologize for being more sensitive than you or anyone else. I smell that shit, damn it. And yes, it bothers me... a lot! A lot of times I smell it with cars, but that's very much the exception. With motorcycles, in the great majority of cases for sure when I catch some of the exhaust.

I already splaned to you how it happens, you're not imagining things, you're not off base. As I said bikes are tuned for performance, and in the case of Harley's for sound as well. A richer mix sounds better, has a lower note with a little more boom to it, and it stinks.
 

jlee

Lifer
Sep 12, 2001
48,518
223
106
I already splaned to you how it happens, you're not imagining things, you're not off base. As I said bikes are tuned for performance, and in the case of Harley's for sound as well. A richer mix sounds better, has a lower note with a little more boom to it, and it stinks.

A richer mix also makes less power than a leaner one. :p
 

slag

Lifer
Dec 14, 2000
10,473
81
101
If you're talking about Harley's, it's because almost everyone has them tuned for power, which causes increased emissions, and lowers engine temps. The stock tune on most newer bikes is lean, which is good for the air, bad for the rider. A rich tune lowers engine temps, and increases mid range horsepower. It also sounds better if you happen to have an after market exhaust.

Purely subjective. I personally can't stand it when someone comes by with a loud aftermarket exhaust and blips the throttle. Give them a noise pollution ticket already. Stock is too loud, aftermarket is just ridiculous.
 

slag

Lifer
Dec 14, 2000
10,473
81
101
1.
After being in the marine industry and changing water separating fuel filters on the stern drive engines for years, I found that 99% of the filters had NO water in them. With the remaining 1% an external source could be found.
2.
As far as the noise mentioned in the first post: The back pressure from a muffler will rob the power from the engine. That is the only reason.


Define external source? I have to pump my boat's tank out because there's water in it and my fuel water separator that I replaced at the end of the last boating season was full of water as well. I've boated for many years and almost always find some moisure in the fuel/water separators, however, last year was the worst.