2012 KTM Fuel Injection & Filter Explained
There is quite a bit of chatter going on about issues with the KTM fuel injection systems. While I have not encountered any problems with either the 2011 or 2012 bikes that I have tested, I thought I would look into the issue to see what I could find and hopefully provide some explanation of the system.
The symptoms of a clogged filter are somewhat vague, but generally a poor running condition and/or a bike that will not idle.
On the 2011 fuel injected bikes, 250 & 350 SX-f and XC-f, the bikes have a fuel filter inside the gas tank. Apparently, some issues with clogged injectors arose with those models. For 2012, all fuel injected bikes now also have a secondary inline fuel filter.
So far, it appears that the inline fuel filter may be the cause of more issues, rather than the cure. The 10 micron membrane is so small that it is very prone to clogging. KTM has issued a technical bulletin (TB1202) that directs dealers to replace the 10 micron filter with an updated, larger opening, 20 micron filter. Part of the service bulletin includes updating all 2011 models to run the inline filter.
This is a warranty service. There are a couple of different part numbers for the repair, depending upon the model of the bike. I have included a photo of one of those parts, where you can see the new filters and hose clamp. The OEM clamp is a one-time use crimp on item, so it needs to be replaced.
Changing the inline filer is a fairly simple task. It requires removal of the seat and gas tank. Then the fuel line is removed from the fuel rail with one Phillips head screw. With this apart, you remove the hose camp at the “L” fitting and access the filter.
Reinstalling the fuel line to the fuel rail is a little more difficult. There is very little space to line the L fitting up properly and the orange O-ring needs to be treated with care to avoid damage. A very light dose of grease around the O-ring will help it slide into place. Make sure to place the O-ring on the male end of the L fitting, not inside the fuel rail. Along with keeping a spare filter handy, I would keep a fresh O-ring also, just in case.
Depending on the model, it may be possible to remove the fuel line directly from the L fitting. That would eliminate the need to remove the L fitting from the injector body. Loosening and rotating the injector body may help with the access. On our 2012 500XC-W model, this did not appear possible due to the location of the frame rail and wiring harness. It looks like the placement on the forthcoming “Dungey” edition 450SX-F will be completely different.
Can a repair be made trailside? The answer is yes, but only if the original hose clamp has already been replaced with a reusable one. In an emergency, the inline filter could simply be removed and run without it.
I spent some time talking with RJ Savage at All American KTM in Ramona to see what he could tell me. He has serviced a number of bikes for this already. The first thing he told me was that not a single bike had shown any sign of dirt in the filter. His belief is that this is simply a fuel issue. What is clogging the filter is varnish or other impurities associated with the gas. You can imagine how easy a pilot jet gets clogged with current fuels and with an opening that is hundreds of times larger than a 10 micron filter.
He has also had some success, in emergencies, simply back washing the filter with either gas and/or compressed air. This eliminates having to take the filter assembly apart. RJ recommends the use of a fuel additive to all of his customers. They have tried a couple of different products and like the Star Tron fuel treatment. Another option would be to use Chevron Techtron fuel injection cleaner at a ratio of 1oz per gallon of fuel. All American has had no repeat issues on bikes that have the updated filter.
I know many riders are concerned about the potential of being stuck out of the trail with any kind of problem that may leave them stranded. Like any new technology, there will be a learning curve for the owners about the system and the maintenance that goes with it.
KTM has not issued any specific care instructions regarding this yet. I expect that at some point they will specify a service interval for replacing these filters. As an owner, I would just treat this as a regular maintenance item, to use a fuel treatment regularly and plan to replace the inline filter at regular intervals.