Saturday, March 20, 2021

Long distance RMX...

 If there's one thing about the RMX it is that it likes fuel.  And it has a itty-bitty 6.2L fuel tank.

I'm probably being a bit hard on it when I say it likes fuel but on a purely km/l it has the worst economy of any of the bikes in the shed.  But km/l doesn't really tell the whole story, with the sort of riding you do on it you don't cover a huge amount of ground but it takes a long time - and generally the engine is running for all that time.  An example:

  • Last weekend the odometer says I rode around 26km
  • I estimate that I used around 3.7l of fuel
  • So about 7km/l - awesome!
  • But it took be somewhere between 2 and 2.5 hours to cover those 26km
  • So at worst around 1.85l/hr
Anyway, I wouldn't have made another lap without refuelling.  Wouldn't it be nice to have a bit more fuel on board?  When I took the bike into the Mangatuks I was a bit shocked at how much fuel it had used and couldn't really tell how much was left in the tank so borrowed a couple of litres to be on the safe side...

So, when an ad came up on Facebook for a second hand IMS tank off a RMZ450 I was interested.  First I had to work out if it would fit the bike and then decide if I really needed it.

It turns out that yes, they fit an RMX and then after some head scratching followed by some haggling I ended up with a 9.8L tank and some spare plastics for an RMZ450.

This morning the tank swap was completed and the following video was most useful in helping me decide to buy the tank and then showing me how to fit it.

First up, the seat and radiator shrouds were removed and then it was time for the tank.  Man I hate those fuel line couplings!

Then it was time to pull the fuel pump and fit it to the new tank.  This was my "it goes this way around" picture before removing the pump from the original tank.

It was easy as to swap the pump over.  This pic sort of shows the size difference between the tanks.

Then it was time to fit the tank.  It took a bit of jiggling around to get it in place and I still may not quite have it in perfectly.  This picture shows the different front mount with the tank not quite in place yet.

The original fittings for the tank strap and seat bracket were also swapped across to the new tank.

Then it was time to fit the plastics.  Unfortunately I had to fit the plastics that came with the tank as one of the bolts holding one of the shrouds on doesn't want to come undone - I think that the captive nut is turning in the plastic of the tank.  Maybe I'll be able to fix that at a later stage.

Then it was seat on and some gas into the tank to see if everything was still all good.  The bike actually took a little bit to turn over (unusual), maybe the pump had drained of fuel in the swap over and needed to run for a bit to pick some up?

And so, now we have another long distance (not sure if I believe the 130km mentioned in the video) off-road touring weapon!

WR showing off it's extra 4L of fuel capacity...

So will I use all that extra fuel?  Well, probably not on trail rides as you generally do smallish loops and can come back to the ute for more fuel - I'll be able to choose whether to fill the tank right up or just half full depending on whether the extra weight (maybe 3-4kg I 'spose) proves to be a problem.  But, it will definitely be good if I go places like the Mangatuks where there are easy trails for miles and I will want that extra fuel.

Now to try it out properly...


  1. Nice tank Andrew and good comments on fuel usage. When I had the GSX-S1000, my road-going fuel usage was usually about 4.3 l/100 km, even when I was getting along fairly briskly. When I did a trackday at Taupo, it was over 10 l/100 km :-)

    1. Damn that's good economy Geoff. Fuel injection is great eh?

      I once got 2.7l/100km from the WR but it's usually in the 3's and 4's - it works for a living though...