Not a particular model specific issue and it is about BMW's...

A recent trip had me thinking about the reason or choices of using a fuel filter. We just returned from a multi-day trip to Taos/Santa Fe, NM in between weather systems...kinda. It started a bit pun intended.

There was a recent thread in Hex/Camheads about adding a fuel filter to a 2011 Camhead RT. This was running thru my head about 120 miles into the trip.

The bikes we started on were Helen's '02 1150R at 108K, and my '09 GSA with 86K. Her's is on the third filter and she's had this bike for all but 2000 miles...roughly 24K on each filter, some in a few years, others a bit longer. My GSA was new in late '08. One FPC and third fuel strip.

We made a 100 mile fuel run after leaving at chilly sunrise and stopped to top off with coffee & gas before making a run towards the Panhandle. We typically go 200+ between stops due to her tanks size. Our typical re-fuel is me closest to pump, but she fuels first so she can roll off first to park if we are stopping for a stretch.

I didn't notice the fuel tanker alongside the Top Tier station until Helen had fueled and I was midway when H pointed to it lurking out of my direct view. I typically do not stop when I SEE one with hoses in place. Helen got about 4.5 gallons, me about 2 as we had not left with full tanks...well I did. Those who know H know this story!

We headed out and within 20 miles of the refuel, H hit the talk button to let me know her bike was misfiring. I thought fuel related after worrying about that tanker, yet my bike kept running fine at that point. After she said it wasn't any better after maybe 5 more miles, we pulled over for me to look it over. All connections to the injectors looked OK and no visible signs of anything major. It just would not idle, but would run OK at higher RPM as I ran it up and down the shoulder of the highway.

A few years ago, one of the spark plug leads failed in the rain, shorting very clearly in the spark plug recess. They are fairly new. It ran differently than that this time, so I don't think ignition. The HES is relatively new and I had not done any major work in the last 2000 miles. Even leaving the throttle advance on wouldn?t help it stay running.

We were 25 miles away from a town w/ any facilities and 125 from home...H said she was OK trying to make it back home or as far as the bike would allow. Me going to get the truck/trailer with back-up bike was option 2 and she wasn?t waving that flag yet.
Luckily only four small towns traffic to deal with as she had to really keep the rev's high when stopped and it died a few times...never got out of 5th either as she said it started lugging and mis-firing. We stopped in LLano about midway home to add some HEET to the remainder of fuel and the last run to the house. It was the first town with an Auto Parts store.

My bike skipped a few times, but I was ultra-sensitive to any sketchy behavior...even caught myself keeping MY rev's high when stopping! Laughed at that more than once. I was sending positive throttle rolls her way I guess. It was gusty so some of that may have been me skipping.

Upon arrival home I noticed the right side had been extremely hot as the Jet-Hot coating on the headers had peeled at the flange...yikes! Maybe the isopropyl was a bit high! I added enough for 3-4 gallons, but she was burning a lot of fuel at 75MPH(legal) in 5th as she ran out 5 miles from home...luckily I had a fuel bottle I keep for her & Chuck and we rolled home. Swapped over to her 12R and left the 1150 in the corner until we returned. I haven't touched it yet.

So, if the fuel was the causal factor, was the amount I got insignificant with a 9 gallon tank and she got almost a full tank, or did the R12's system let it pass on thru. Or did she get the brunt of the crud by going first?

AND...if I had her filter where it should have been by now ,could I have just drained the fuel and popped on a new filter and kept going? If we were not close as we were to home and not had bike options, I would have had to tackle it anyways.

As a point of reference, the R with it's steel tank, and the scarce ST were the only R1200's with a OEM filter mounted outboard the tank.The other models do not have a filter at all. My 09GSA and our R12S do not have one, nor do our K12S?s. My RT also was filter-less. We both are close to 200K on several late model Beemers with no fuel issues...other than strips and a FPC. oh, and a few fuel run-outs on 1100/1150's

Helen's R1150R still has the internal's move to the outside on my list but not high up there. It might have made a diff to this tale.

Our bikes are 50/50 on filters...other than her R12R and her ?07 Thumper GS, none of our post 2005 bikes have a filter I have added them to the 70's Airheads since both had iffy tank linings. You know we get moisture laden fuel on occasion, are the newer bikes able to digest it better w/out the filter?

T-shooting after I added the HEET will not help me in regards to moisture contamination, hopefully the injector pattern test will help decide if the filter is somewhat plugged. This time I will move it?I guess.