External Fuel Filter Mod - A Good Idea?

[BUSTED]

The difference is I don't know anyone that wants to try and change out a plugged filter in a cages gas tank along side of the road or in a parking lot. When the cage gets stopped, it gets towed. That's something most cyclist like to prevent! I wouldn't want to drop a,(my vehicles run 18to40 gal. capacities), tank of gas for a roadside repair.

[smiller]

While we are dispelling urban legend, lets look at another fact. The ignition temperature of gasoline is somewhere around 425 degrees F (232C). It is not likely, unless the bike has been running very hard or left idling for an extended period that any part of the motor or even the exhaust piping is that hot. Therfore, unless you go looking for the source of the smell with a lit match, you have no worries about a filter bursting or a line coming off from the fire aspect.

 

 

This illustrates the pipes under somewhat extreme conditions.

 

Jim

Ah yes, well under 425 degrees. That image makes me feel completely comfortable with spraying gasoline on those pipes...

[rondob4]

It was this image from another thread that inspired this discussion. I saw my pipes emitting similar shades one morning when I left the bike idling with the "choke" on. While the potential cause may be different, the results are the same. Any one know of a do-it-yourself on-board fire suppression system?

[GCD]

While we are dispelling urban legend, lets look at another fact. The ignition temperature of gasoline is somewhere around 425 degrees F (232C). It is not likely, unless the bike has been running very hard or left idling for an extended period that any part of the motor or even the exhaust piping is that hot. Therfore, unless you go looking for the source of the smell with a lit match, you have no worries about a filter bursting or a line coming off from the fire aspect.

 

 

This really seems to be mixing the issue. OK, the ignition temp. of gasoline is 425 deg. if you say so. We're really concerned about the flashpoint of the vapors.

 

Take a look at this link: web page

 

It indicates the flashpoint of gasoline is minus 45 deg.F.

 

Also:

Gasoline is readily available and routinely used in most households. In spite of the routine use of gasoline, many people are unaware of or unappreciative of the dangers of gasoline. Gasoline is dangerous because it is highly volatile – the fumes are capable of ignition up to 12 feet away from a pooled source. This inherent danger is further multiplied by its explosive potential. Flammables burn at close to room temperature (100 degrees F), when they are near a spark, flame, or even static electricity. It can float on water and may spread long distances, making ignition and flash back possible. Gasoline vapor is highly explosive and may ignite as a “fireball” with a temperature of 15,000 degrees F.

 

 

I'm not worried about the fuel in the tank, just the vapors that would be present if the mod caused a leak.

 

In my earlier post, I mentioned that I had gone back to the filter in the tank. I pointed out that on the RT, the external filter must be located back near the shock preload adjuster, right next to the rear tire. A run of about 3 feet of external line must be routed also. This, TO ME (only) introduces unnecessary additional risk for a pretty small gain. I imagined me trying to get my insurance co to payoff a claim, for instance, if a leak caused the bike to roast. That of course says nothing about the risk of me being the item barbequed.

 

I don't worry about the fuel filter anymore. I carry a fresh one while on the road along with the tools to fix it, and if it needs to be replaced, it gets done then.

 

Cheers,

Greg DeWit

Evergreen, CO

[big-t]

Ah yes, well under 425 degrees. That image makes me feel completely comfortable with spraying gasoline on those pipes...

 

 

I,m with you....I was on a riding lawnmower when the fuel line came loose and dumped fuel on the engine.The resulting fireball scorched my pants and shoes,but the hood saved my my upper torso from the blast.Within a couple of seconds the flames were at roof level.

 

It falls under the catagory "you had to have been there to realize how bad it was".

 

 

No thanks,I can spend a few extra minutes pulling the filter from the tank.

[bmweerman]

This really seems to be mixing the issue. OK, the ignition temp. of gasoline is 425 deg. if you say so. We're really concerned about the flashpoint of the vapors.

 

To further confuse the issue I offer this:

 

n addition to ignition temperature, other properties associated with the flammability of a liquid are its flash point, flammable range, and vapor density. The flash point is the temperature at which a flammable liquid vaporizes and is therefore able to ignite.

 

So...is flash point being defined here as the temp at which gasoline will vaporize or the temp at which it will ignite?

[Joe Frickin' Friday]

Take a look at this link: web page

 

That was a, uh, interesting document. A fireball temperature of 15,000 degrees Fahrenheit? That's pretty hot, hotter than anything I've ever heard of; more reliable sources give a maximum fireball temp of about 4000 degrees (tho that's still pretty stinkin hot).

 

And I'm still trying to figure out why a document about gasoline safety would include a picture of a pyroclastic flow on page 2...

 

As for the much-debated external filter mod...has anyone actually ever actually heard of an actual incident of actual filter rupture on an external filter mod?

[Turbodog]

Until you've changed a fuel filter on an Oilhead, you can't begin to appreciate a properly routed external fuel filter.

 

Can I add a few of those? And a Hear, Hear! too.

Geez what a pain that job was.

[Joe Frickin' Friday]

n addition to ignition temperature, other properties associated with the flammability of a liquid are its flash point, flammable range, and vapor density. The flash point is the temperature at which a flammable liquid vaporizes and is therefore able to ignite.

 

So...is flash point being defined here as the temp at which gasoline will vaporize or the temp at which it will ignite?

 

The first definition above is murky. All liquids have a vapor pressure that varies with temperature; IOW, at any temperature, a free liquid surface will produce some quantity of vapor. The flash point is the temperature above which it is possible to produce enough vapor result in an air-fuel mixture capable of sustaining a flame front; below the flash point, any mixture that forms is just too lean to burn.

[ShovelStrokeEd]

Seth,

Dyno runs with no cooling air stream don't count.

 

Take even a warm night and run your bike down the highway at full throttle. Doubtful you'll see much in the way of pipes glowing red. In addition, that same air flow is going to blow any fuel vapors (which are more flammable than liquid gasoline) back and away from the pipes. It is doubtful that the cylinder heads, except right next to the exhaust ports see anything even approaching the oil temperature as their surfaces are cooled by the air flowing over them.

 

I'd worry much more about liquid fuel getting into the harness and creating a short circuit which could easily generate sparks, and thus produce methyl ethyl bad stuff leading to a fire.

[bmweerman]

n addition to ignition temperature, other properties associated with the flammability of a liquid are its flash point, flammable range, and vapor density. The flash point is the temperature at which a flammable liquid vaporizes and is therefore able to ignite.

 

So...is flash point being defined here as the temp at which gasoline will vaporize or the temp at which it will ignite?

 

The first definition above is murky. All liquids have a vapor pressure that varies with temperature; IOW, at any temperature, a free liquid surface will produce some quantity of vapor. The flash point is the temperature above which it is possible to produce enough vapor result in an air-fuel mixture capable of sustaining a flame front; below the flash point, any mixture that forms is just too lean to burn.

 

Cool...thanks for that info ...still a little murky to my pea brain but getting better....

 

Geeezz... I really should have paid attention in physics class

 

Cameron

[Joe Frickin' Friday]

I'd worry much more about liquid fuel getting into the harness and creating a short circuit which could easily generate sparks, and thus produce methyl ethyl bad stuff leading to a fire.

 

I wouldn't even worry about that. Gasoline is an extremely poor conductor of electricity (a major factor in its static electricity hazard).

[smiller]

I wouldn't even worry about that. Gasoline is an extremely poor conductor of electricity (a major factor in its static electricity hazard).

Evidenced by the fact that the fuel pump runs bathed in gasoline.

[SnowDog]

I did the external filter mod on my long gone RS11. It worked great for many 1000's of miles. Just use the fuel injection rated hose and the fuel injection clamps, not the worm type. THINK about the hose placement and use ty-wraps to secure it safely. I will do my GS when the time comes. A really great mod if done properly.

Steve

 

It's not the hose that is the problem. A good hose can easily hangle more pressure than the pump is capable of.

 

It's the filter itself! If it gets plugged, the pump can easily get up to 150 to 200psi trying to force fuel through a clogged filter. This is exactly what happened to me. The bike will still run just fine, since the fuel injector rail still has the normal regulated pressure.

 

The problem is that the aluminum fuel filter canister was NEVER designed for this kind of pressure. In fact, some time ago, BMW discontinued one manufacturer of filters, because they stamped the part number into the housing, thus weakening it. These filters were known to split open under pressure.

 

So if you do an external mod, then be damned sure you check your filter regularly. If it gets plugged, the pressure the pump is capable of can most certainly result in it splitting open.

 

Bob.

 

I think this is sensationalism. Hundreds have done this mod with no problems. I have only once heard of a filter bursting, and it was a non-FI filter.

 

Besides, the hoses wont take 200 PSI either. Not that I have heard of this before, though I am not saying it hasn't happened.

 

Jim

 

 

FYI - I am almost certain my '05 R1200ST has it's fuel filter outside the tank. It uses the same part number filter as my R110GS oilhead. Hope it doesn't split because BMW will be in a heap of trouble.

[BUSTED]

The filter relocation on an RT does not have to be mounted rearward. In fact I mounted several without adding any fuel line for the location as I simply placed the filter in BMW fuel line. The only fuel line I added was in the tank to replace the filter.

 

 

attached pic

[Jim VonBaden]

While we are dispelling urban legend, lets look at another fact. The ignition temperature of gasoline is somewhere around 425 degrees F (232C). It is not likely, unless the bike has been running very hard or left idling for an extended period that any part of the motor or even the exhaust piping is that hot. Therfore, unless you go looking for the source of the smell with a lit match, you have no worries about a filter bursting or a line coming off from the fire aspect.

 

 

This illustrates the pipes under somewhat extreme conditions.

 

Jim

Ah yes, well under 425 degrees. That image makes me feel completely comfortable with spraying gasoline on those pipes...

 

Funny you say that. My quick disconnect broke on my 11GS and was spraying fuel all over, including on my hot pipes, and it clouded up, but no fire. Scared the crap out of me though!

 

Jim

[Jim VonBaden]

 

FYI - I am almost certain my '05 R1200ST has it's fuel filter outside the tank. It uses the same part number filter as my R110GS oilhead. Hope it doesn't split because BMW will be in a heap of trouble.

 

You are correct. Directly over the left exhaust pipe!

 

No worries though, BMW know's what it is doing!

 

Actually, it sure makes changing it easier.

 

Jim

[No_Twilight]

[quote

Funny you say that. My quick disconnect broke on my 11GS and was spraying fuel all over, including on my hot pipes, and it clouded up, but no fire. Scared the crap out of me though!

 

Jim

 

Jim,

I love it when we get real first hand experience posted here. I'll take one of these post for every 10 posts with unfounded recommendations in them. Of course one data point doesn't mean we'll never have a fire but it's much better than none. And you bring up another good point: the quick disconnects are MUCH more likely to fail than the fuel filter. Anybody on the other side of the argument thinking about removing their quick disconnects and replacing them with a passive connecter?

 

Thanks, Jerry

[smiller]

FYI - I am almost certain my '05 R1200ST has it's fuel filter outside the tank. It uses the same part number filter as my R110GS oilhead. Hope it doesn't split because BMW will be in a heap of trouble.

 

Yeah, I'm not a big proponent of the external fuel filter mod but even I'm not sure why discussion of this topic always seems to generate a lot of 'splitting fuel filter' concerns because as others have mentioned this seems to be a very small possibility at best. Rather, to me the entire safety issue hinges on whether the individual doing the mod simply did it right in terms of mounting components, routing hoses, etc. I've seen very professional examples that looked better than stock and I've also seen some pretty questionable work (that the owner was quite proud of, BTW ) that looked like an ambulance ride waiting to happen.

 

I guess it all comes down to 'Do you feel competent today, punk..? Well, do ya..?'

[No_Twilight]

FYI - I am almost certain my '05 R1200ST has it's fuel filter outside the tank. It uses the same part number filter as my R110GS oilhead. Hope it doesn't split because BMW will be in a heap of trouble.

 

Yeah, I'm not a big proponent of the external fuel filter mod but even I'm not sure why discussion of this topic always seems to generate a lot of 'splitting fuel filter' concerns because as others have mentioned this seems to be a very small possibility at best. Rather, to me the entire safety issue hinges on whether the individual doing the mod simply did it right in terms of mounting components, routing hoses, etc. I've seen very professional examples that looked better than stock and I've also seen some pretty questionable work (that the owner was quite proud of, BTW ) that looked like an ambulance ride waiting to happen.

 

I guess it all comes down to 'Do you feel competent today, punk..? Well, do ya..?'

 

 

Well said. Indeed we should probably offer a disclaimer that this mod should only be done by those confident in their mechanical abilities. I give similar advice on all battery mods. A shorted battery cable will burn your bike up very quickly. I believe that is what causes most or the RV fires you see beside the road. The battery is almost always relocated and a long cable is run past lots of sharp frame corners.

 

--Jerry

[BABABeemer]

I agree that if you routinely take your bike in for factory servicing and only use the best, highly filtered fuel, you are probably better off with the stock arrangement,however,if you travel to areas of the world where you can't trust the quality of the fuel such as Northern California, then I would suggest the modification along with some protective sheathing over the fuel lines around the throttle linkage.