Triumph Rat Motorcycle Forums banner

1 - 3 of 3 Posts

2 Posts
Discussion Starter #1
Has anyone converted a 955i to an external fuel filter? I find a lot of writeups where people do this to various BMWs and V-Stroms, but nothing on the Triumphs, either here or over at Advrider.

Here’s what I’m planning to do, unless someone talks me out of it:

1. Pull the plate out of the tank that has the pump, filter, regulator, etc. mounted to it.
2. Remove the filter and replace it with a length of new hose.
3. Replace all the rubber hose and clean out the suction sock while I’m in there.
4. Re-install the plate.
5. Cut the fuel hose that goes from the tank (lower port) to the fuel rail, and install an inline filter. The Wix 33323 looks pretty appropriate. There are also several generic FI filters with 3/8 hose barbs listed in the Jegs catalog, for Holley and Edelbrock FI systems.
6. Live happily ever after, happy in the knowledge that it will be easier to troubleshoot and repair. And when I get the recommended 12k or 25k (depends on who you listen to) on the bike, I can change it in 10 minutes.

Here’s another thing I’d like to hear someone with more experience discuss:
The stock Triumph system pumps fuel out to one end of the fuel rail. The other end of the fuel rail has a hose that returns to the tank. Once it’s inside the tank, it goes to the pressure regulator. The regulator dumps the excess flow right there inside the tank.

Why do they do this? It seems much simpler and more direct to tee the fuel line just downstream of the pump, inside the tank, go directly to the regulator, and plug the other end of the fuel rail. There are many bikes and cars that do it that way.

This also seems easy to modify:
1. Cap or plug one end of the fuel rail (I’m thinking that the end with the bolted-on hose barb would be easy and clean to cap).
2. Remove the upper (return) quick-disconnect fitting from the tank, and plug the hole.
3. Remove the tank plate (again).
4. Remove the hose that goes from the upper (return) port to the regulator.
5. Cut the hose that goes from the pump to the pressure port. Right in the middle of the long piece of hose that replaced the filter seems like a logical spot.
6. Install a hose barb tee there, and run a short hose from that tee over to the pressure regulator.
7. Replace the plate.

And now I see one possible reason that they might do it the way they do. In the stock setup, the filter is right after the pump, and ALL the fuel is flowing through the filter, both the fuel that’s being used by the injectors AND the fuel that’s getting dumped though the regulator. That means that a lot of fuel gets pumped through the filter and back into the tank. Kind of like a kidney-loop or scrubber loop. That’s kind of nice, and would make the fuel in the tank cleaner and cleaner.

It would also ensure that the fuel going through the regulator has been through the filter. My mod would send dirty fuel through the regulator, which can’t be good for its various tiny orifi and moving parts.

So maybe I just talked myself out of that part of the mod.

I’d love to hear advice and input from some of you guys with more fuel injection experience or more common sense than I have.


1,722 Posts
Not sure why you'd want to bother. It's easy enough to get the plate off the tank and it is only every 12K (although TBH as UK fuel is very clean I didn't bother changing mine at 12).

I suppose if you were in the wilds of Mongolia or somewhere it might be worth while.

WRT your second point I think the later 955is do it this way - certainly there is only one fuel pipe from the tank.

2,340 Posts
Sorry, got to agree with Ian, it's not worth the hassle.

I've been servicing my own 955 for a good few years now and I've never replaced the fuel filter, and never had a problem ??

Having read this thread and realised mine hasn't been changed for at least four years, I'll do mine for next riding season. Thanks :)
1 - 3 of 3 Posts