So the last week or ten days, I’ve noticed a really rough idle and rough low throttle. The Monster would hesitate and almost stall then catch itself. Even when fully warmed up. Adjusting the fast idle didn’t do much to fix it; that is, it helped keep the revs up, but it still would almost stall. Kind people at Ducati Monster Forum suggested the fuel filter.
While I knew it was soon time to replace it, I didn’t think it’d be this son. Last one I replaced was at ~36,000 miles and I’m now at 58,000 miles.
Either way, replacing it seemed to fix the problem. How is it done? Keep reading.
This is a 2004 Monster 620 with a SSR fuel cap. While other monsters may be different they should all be pretty similar. Two critical pieces to this job. 1) As always, take your time, go slow, don’t rush. 2) Drain off or use as much fuel as possible before doing this. Remember, if you have a full tank of gas, you’re going to be digging your hands into that gas the whole time you’re doing this job. Be smart, work safe.
On the OEM cap, there is another bolt hiding under the cap, which bolts the cap to the neck. Make sure to remove that one too. Take a mental note of the alignment of the bolt holes. This will be important when you’re re-installing everything.
2. Along the rim of the neck are a bunch of 2mm grub screws.
Here you can see it pulled out and how far out the grub screws have to come out. Again, don’t undo them all the way. I wish I had a ball-end hex for this. The folding hex I used was a pain in the ass and my smallest straight hex is 2.5mm.
Use a standard screw driver to loosen the clamps. I get them loose with a driver, then use my fingers to undo the clamps almost completely. The filter has barbed ends on it’s pipes so you need to clear those.
Here’s the new filter. You can see it has an arrow which is not only the direction of fuel but also the direction of travel, easy to remember. Don’t mess it up. Why? I dunno, but they wouldn’t put the arrow on if it wasn’t important, right?
4. Attach the ‘back’ end first. There’s less slack on that hose and it’s tight quarters so you want as much versatility as possible to get the hose on and the clamps tightened up. If you hook up the ‘front’ first you’ll be challenged with mobility inside the confines of the tank. From experience I can tell you, do the back line first.
6. Now the hardest part. Pressing the neck and gasket back into the tank. This takes a little finesse and technique. I can tell you the 2nd time I did this part it took about 1/4 the time it took me the first time.
Remember when I said above to take a mental note of the bolt holes? Make sure you’ve got the bolts lined up the way you want I won’t be wrong, but if you want the gas cap to open the same way, the bolts need to be in the right place.
Work your way around, I use a star pattern but that’s probably not necessary. Then once they’re all in, I go once around clockwise and make sure they’re all tight.
10. Replace the gas cap and you’re done. Of course you want to start and let the bike idle a little to make sure all is good. When the fuel pump primes, it may sound a little funny, different than normal, because it’s pumping fuel into the empty filter. Nothing to worry, this is normal.
Not so bad right? It seems like a lot of steps but not really, I just took a lot of pictures here to illustrate every step. And you can do it all with normal household workshop tools.
Remember, Ducati aren’t powered by unicorn hairs and pixie dust. They’re machines and just like any other machine they can be fixed. Get your hands dirty and enjoy. For me, it’s time for a beer. Keep riding and keep it two slow, everyone!