O.k. I did a quick search in the Halls of Wisdom about swapping fuel filter and internal fuel lines but didn't see anything so figured I would post this up although I don't claim to be very wise. This was a swap of fuel filter and fuel lines on my 2001 ST4 so I am not sure how relevant it is to other models but here was the process for me with some pics. A little background, I purchased this ST4 about two months ago with 3700 miles on it, so not much use for the bike but the fuel lines were pretty bad. (It has about 4600 miles now) This project started because of a drip on the overflow line that would not stop. Hopefully it may help someone out some day.
Step one is obviously to access underneath the tank.
Step two is remove the hoses from the fuel pump. I placed a towel underneath to catch any fuel that leaked out. I also used a small pan to catch some initial flow.
Step Three is removing the tank. Make sure you have a nicely padded place to set it down before you pull it. I used two old towels on the work bench.
Underside of tank with fuel pump still attached.
Step four remove the fuel pump assembly. I used a flat head screw driver to pry the edges loose. It is fitted very snug so it takes a little work. Be careful to not ding up the tank if you use this method as you could skew something so the pump won't fit properly on reinstall. Also if you are going to use the gasket again be careful not to tear it. I also took a black sharpie and made a couple marks on the pump and tank to assist with reinstall. It tells you where the top of the pump should go on the base plate but I like to make sure I don't screw it up......
Once you have the pump out remove the lines and electrical plug.
Fuel Pump removed.
Prior to taking out the pump you can drain the gas with the little plug set right behind the fuel pump assembly. I did not have much fuel in the tank so I pulled the pump first and then drained the tank, leaving a little bit inside to help clean it out with papertowels. Wiped the tank with papertowels first and then used a shop vac to suck up the rest after letting the tank sit a day and dry out.
Here are a few photo's of the inside of the tank and the fuel lines that have gone bad. Notice all the fuel line particals in the tank. Not good.
One of the papertowels used......dirty
Pics of the tank cleaned out and prepped for reinstall. Also a pic of the fuel pump seal which I reused because it was still in pretty good condition. Not a bad idea to have a new one handy before tackling this project though. I have one on order from LT at DesmoTimes but since it was in decent shape I used it again and will save the new one for next time.
O.k. Now the tank is clean and its time to hook up the new fuel lines. I purchased fuel injector hose from NAPA SAE 30R9 180 PSI 5/16th which is technically not rated submersible, you need SAE30R10 for that I believe. There is lots of opinions about whether you need to go with the more expensive SAE 30R10 or not. I am not going to get into that but LT over at Desmo times has been working on Ducs for 10+ years and uses a less expensive hose so I figured it was good enough. If you change them out every 3-4 years it should be good. FYI the SAE 30R9 is about $10 a foot and the SAE 30R10 is around $30 a foot and usually needs to be ordered. The original clamps were in good shape so I reused them. I purchased a NAPA Gold 3032 Fuel Filter which fit fine. Its just canted a little in the carrier.
A few pics of the new hoses and old hoses.
Old fuel lines from inside the tank.
New fuels lines cut to size.
New lines installed
Now cut to size the fuel lines for the pump and remove the old and install the new. Here is the new hoses and new fuel filter installed on the pump. I left the breather lines alone as they were in good shape yet.
After getting the new gear set up time to reinstall. Hook up the lines inside the tank and plug the electircal connector back in and place it back in the tank.
Not sure how well it showed up but I used a little petroleum jelly spread around the edge of the tank to help get the fuel pump to fit back in.
A little finenessing with and a couple taps from a rubber mallet and presto its back in.
Now you just slap the tank back on and reconnect the fuel lines and you are done. I ran it up to operating temp after reinstall and then lifted the tank again to make sure I didn't have any leaks. All was good so far anyway.
Total project time for me was about 90 minutes give or take and I am just a garage monkey really. I spread it out over a couple days to let the tank dry and stuff but actual work time was around an hour and half. A pretty straight forward job without much fuss.
Oh and one last pic of the inside of the old fuel filter........I couldn't resist cutting it open. It was definately in need of replacement.
Hope maybe this will help someone out. I also found out we are limited to 20 photos on a single post so I have more detailed shots if anyone needs them.
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