External fuel filter mod.

[King Herald]

The m5 studs on the fuel tank, for the fuel pump plate on my ‘97 1100r are on their very last legs, and every time I’ve done the fuel filter service I’ve expected one to totally strip, but with a few washers to get the nuts in just the right place I’ve survived 8 years with the bike. 
 

It was time go into the tank again and also swap out the various hoses, as they have been in there since I bought the bike. I hate doing this job, and I’ve an ailment that is making my fingers more and more weak and feeble, so it’s all the more stressful. 

So, I decided to do the external fuel filter mod this time. 
 

Anyway, trying to get the hose loop fitted, to replace the filter,  and get it to clear the mesh sock, and also allow the low fuel float mechanism to move freely, I managed to snap the plastic base to the float meter.

 

 So that’s gone in the bin, I’ll have to count miles between refills. 
 

After a lot of struggle and messing about it was all back in the tank and on the bike, so time to run the external hose and mount the filter.

 

Somehow I found I didn’t have enough hose to run it like the article by Rob Lentini showed, so I ended up putting it just under the edge of the fuel tank. I found a piece of rubber hose that slipped tightly over the outside of the filter, to prevent any changing of the soft aluminium on anything. It sits quite firmly there and can’t move at all. I zip tied it to be sure.  With the plastic tank trim on it can’t even be seen. 

 

This is the super tidy Lentini version:

 

 

[RadioFlyer]

I always found it odd that the maintenance schedule for the oilheads calls for periodic replacement of the fuel filter but subsequent generations of the boxer do not.

[9Mary7]

I've never changed one on any of my bikes........

[Skywagon]

1 hour ago, 9Mary7 said:

I've never changed one on any of my bikes..

Me neither. 

[Dave_in_TX]

51 minutes ago, Skywagon said:

Me neither. 

Same here and two of those bikes went over 140k miles.

[King Herald]

7 hours ago, RadioFlyer said:

I always found it odd that the maintenance schedule for the oilheads calls for periodic replacement of the fuel filter but subsequent generations of the boxer do not.

So many guys ride these type bikes on trips around the world, I’ve often wondered how they do a filter change if they get a tank full of really bad gas in the middle of the Sahara, or the Bolivian Altiplano. It’s not the sort of thing you change out the filter at the side of the road. 

[RadioFlyer]

3 minutes ago, King Herald said:

So many guys ride these type bikes on trips around the world, I’ve often wondered how they do a filter change if they get a tank full of really bad gas in the middle of the Sahara, or the Bolivian Altiplano. It’s not the sort of thing you change out the filter at the side of the road. 

The days of BMW being an RTW bike are long gone. Check out Horizons Unlimited to see what the current RTW bikes of choice are.

[Jim Moore]

I've had two clog on me in my 350,000 miles of oilhead ownership. I was able to limp home and fix them, but it was a huge PITA. If you don't plan on servicing it I definitely would toss a spare in the saddlebag. 

[dirtrider]

10 hours ago, King Herald said:

So many guys ride these type bikes on trips around the world, I’ve often wondered how they do a filter change if they get a tank full of really bad gas in the middle of the Sahara, or the Bolivian Altiplano. It’s not the sort of thing you change out the filter at the side of the road. 

Morning King Herald

 

The BMW fuel filters probably  have been changed in the Sahara, or the Bolivian Altiplano, or in other 3rd world areas. If the fuel is contaminated enough to plug the internal fuel filter in one filling then it has probably also plugged the pump intake sock. Plus if it's that bad then the tank should be removed & the tank cleaned out inside with new (cleaner) fuel added. Or at least the contaminated fuel run through a couple strainer fine micron filters before dumping back into the tank. 

 

I typically don't ride in an area where fuel is that bad but the few times that I have I carried a fuel tank filler-neck pre-filter (you pour the gasoline into the tank through that fine-micron filler neck filter).

 

An external filter is something that I am usually not fond of as it puts more engine heat into the fuel. In your riding area that probably isn't a big deal as it doesn't get that hot & I'm pretty sure the UK has gasoline vapor pressure limits. 

 

On the other hand, if a rider is riding in an unregulated country that is very hot with unregulated high vapor pressure gasoline then adding more engine heat to the fuel can cause fuel boiling,  vapor bubbles, & fueling control issues.  

 

Any way you look at it, having a tank full of contaminated fuel on a fuel injected motorcycle in the out-back is going to be a very big pain in the A$$.  

 

Those side of the road repairs would surprise you, I have installed an HES on the side of a road (actually a way-off road trail) & installed a final drive crown bearing & seal on the side of a very rural road.  

 

 

[King Herald]

On 5/27/2024 at 12:26 PM, dirtrider said:

Morning King Herald

 

The BMW fuel filters probably  have been changed in the Sahara, or the Bolivian Altiplano, or in other 3rd world areas. If the fuel is contaminated enough to plug the internal fuel filter in one filling then it has probably also plugged the pump intake sock. Plus if it's that bad then the tank should be removed & the tank cleaned out inside with new (cleaner) fuel added. Or at least the contaminated fuel run through a couple strainer fine micron filters before dumping back into the tank. 

 

I typically don't ride in an area where fuel is that bad but the few times that I have I carried a fuel tank filler-neck pre-filter (you pour the gasoline into the tank through that fine-micron filler neck filter).

 

An external filter is something that I am usually not fond of as it puts more engine heat into the fuel. In your riding area that probably isn't a big deal as it doesn't get that hot & I'm pretty sure the UK has gasoline vapor pressure limits. 

 

On the other hand, if a rider is riding in an unregulated country that is very hot with unregulated high vapor pressure gasoline then adding more engine heat to the fuel can cause fuel boiling,  vapor bubbles, & fueling control issues.  

 

Any way you look at it, having a tank full of contaminated fuel on a fuel injected motorcycle in the out-back is going to be a very big pain in the A$$.  

 

Those side of the road repairs would surprise you, I have installed an HES on the side of a road (actually a way-off road trail) & installed a final drive crown bearing & seal on the side of a very rural road.  

 

 

Morning DR,

In hindsight I wish I’d just left it alone now. The hoses seem as good and solid as the new ones I bought to replace them with, so could probably have stayed in there for several more years. And if the filters do last as long as people have said then that could also have happily stayed inside. 

One thing I did find was the very end part of the plastic manifold tube, on the pressure side, had broken off, maybe 1/8” of it, which has the slight taper to help the rubber hose slip over it. I can’t imagine how just that little end piece would snap, there’s no load on it. I noticed it when I saw the brass insert peeking out the end. I hope it’s not a sign of impending doom…

 

[dirtrider]

18 minutes ago, King Herald said:

Morning DR,

In hindsight I wish I’d just left it alone now. The hoses seem as good and solid as the new ones I bought to replace them with, so could probably have stayed in there for several more years. And if the filters do last as long as people have said then that could also have happily stayed inside. 

One thing I did find was the very end part of the plastic manifold tube, on the pressure side, had broken off, maybe 1/8” of it, which has the slight taper to help the rubber hose slip over it. I can’t imagine how just that little end piece would snap, there’s no load on it. I noticed it when I saw the brass insert peeking out the end. I hope it’s not a sign of impending doom…

 

Morning King Herald

 

With the 1100 not coming from the factory with quick disconnects there is a good chance that the fuel manifold line was cut off, or broken off, by someone removing the fuel tank in it's past life. It can, at times, be very difficult to remove the stuck hose from the plastic line.

 

On the life of the fuel filter, if clean fuel is used then the fuel filter will probably last longer than the internal high pressures hoses do. 

 

If dirty or contaminated fuel is put in the tank then even a new filter will plug quickly. 

 

In the USA we have another concern & that is the emission Evap can sucking in road water then degrading & allowing fine carbon particles to enter the fuel tank. That black goo can plug the fuel filter, fuel injector screens, & even plug the fuel pump intake sock.   

[King Herald]

41 minutes ago, dirtrider said:

Morning King Herald

 

With the 1100 not coming from the factory with quick disconnects there is a good chance that the fuel manifold line was cut off, or broken off, by someone removing the fuel tank in it's past life. It can, at times, be very difficult to remove the stuck hose from the plastic line.

 

On the life of the fuel filter, if clean fuel is used then the fuel filter will probably last longer than the internal high pressures hoses do. 

 

If dirty or contaminated fuel is put in the tank then even a new filter will plug quickly. 

 

In the USA we have another concern & that is the emission Evap can sucking in road water then degrading & allowing fine carbon particles to enter the fuel tank. That black goo can plug the fuel filter, fuel injector screens, & even plug the fuel pump intake sock.   

Morning DR, 

It could well have been me who damaged that pipe in a previous service. You’re right, those hoses can be a real pain to get off, and sometimes I’ve cut them, but oddly enough this time they both slid off scarily easy once I loosened the clamps. 
 

We don’t get the charcoal canister thing here in the U.K., just a couple of hoses hanging out the bottom of the bike.