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Hello everyone! This is my first post and I hope it helps someone who might need it!I wanted to do a quick write up since I havent seen much on the project I just completed. I have a 2005 Road King (FLHRS) and I just finished converting it FROM carbureted TO Delphi EFI. Why? Because I wanted to. So I guess now I have an FLHRSI.
I ran into a few small issues along the way that Ill explain, but overall doing the conversion went pretty smoothly and was just time consuming. I have made a parts list of everything you would need at bare minimum to get the job done. Next winter Ill be building the motor so I went with an HPI 51mm throttle body, an HPI air cleaner, and a Thundermax tuner but you could just go with the factory Harley stuff to save some coin.
I have the fuel tank from the 05 models that can either be EFI or carb so the swap there was easy. I just got everything needed and assembled the tank. Removing everything for the carb (fuel level float and top plate, petcock) and installing the EFI stuff (fuel pump, fuel lines, Quick Disconnect line). I ran into a few issues regarding the fuel pump top plate and the wiring harness, but you can read about those below.
Once the new-to-me harness was run, the throttle body was on/connected, and the tank was put back on I put on the air cleaner and got the dash set up (which I had some issues with see below). Then I primed the fuel pump a few times, plugged in my laptop to the Thundermax, loaded a base tune (from Shop67), and then fired it up. It started right up with no issues; all my readings were great on the Thundermax tuning software, and the throttle was extremely responsive. Im currently running the auto tune before I plug it back in, but everything seems great. Gone are the days of messing with the choke and throttle to get it to start, then letting it warm up for what seemed like forever. I can just get on and go!
I did a few other maintenance things while the bike was in pieces that arent necessary but since I had the tank seat and bags off, I figured why not. I installed Fueling head breathers, ran new throttle and idle cables, flushed my brake lines, upgraded my rear suspension, replaced all the fuses in the new-to-me wiring harness, etc.
Now onto the issues.
The first issue I ran into was routing the EFI portion of the wiring harness. The main part of the wiring harness was pretty simple. I started at the bars and cut/replaced clip ties as I went, unplugging things from the old and into the new and followed the original routing pattern. I got the main section fully replaced and then realized I had a whole new section of harness for the EFI stuff. Eventually I found an online version of the service manual and with the help of some photos from friends I got the harness ran properly and connected my Thundermax to the EFI harness and on the EFI version of the ECM bracket.
The second issue I ran into was the lack of bolts for the sensors on the throttle body. I ordered an HPI throttle body and all the sensors I needed. Since I did not have a throttle body to begin with, I did not have sensors or bolts for anything to re-use. Of course, none of the sensors come with bolts so I had to source the bolts I needed to mount the IAC sensor and the Throttle Position sensor to the throttle body. Your best bet is to use a tap and go to your local hardware store. I went to three different dealerships in my area and none of them could tell me what bolts I needed.
The third issue was the top motor mount. Apparently, Harley made the top motor mount bracket different between the EFI and Carb versions of the bike. The line running from the gas tank to the injectors did not fit with the carb version top motor mount. There is a significant lack of bend in the mount to allow that line to fit underneath and be routed like its supposed to. Once my correct mounting bracket came in the line fit with no issues.
The fourth issue was the fuel pump harness. To save some money I purchased a fuel pump from an 06 touring bike. It was about 300 dollars cheaper than anything I found for the 04-05 versions, and since I was going to rebuild everything anyways the condition of the pump and associated pieces was not important. After I had everything installed on the rest of the bike, I went to plug in all the connectors for the dash and realized that the fuel pump connector on the harness is a rectangle three-pin connector and the female end on the fuel pump plate is an oval four-pin connector. I ordered a short wiring harness meant for that fuel pump and then cut the three-pin connector off the harness and wired it into the new four-pin connector. The fourth pin is a second ground (according to the wiring diagram) and is not totally necessary, so I just capped the wire. The fuel pump primed right up with no issues once the connectors were good to go.
The fifth and final issue was the bracket that the dash bolt slides into in the fuel pump top plate and then the nut tightens down on to hold the dash in place. On my original fuel pump plate the bracket is located at the bottom. However, on the new one the bracket is in the middle. I tried to install the dash but there was no way the bolt could go through the dash in its current location. I ended up finding a piece of Din Rail at my work that worked perfectly as a bracket for the bolt. I cut a few pieces off and trimmed them down to get a flush fit, then cleaned both sides and used a metal bonding agent (JB weld, Loctite, epoxy resin) to hold it in place. So far so good, its holding just fine.
Let me know if you have any questions. Ive included some photos for refence
Welcome to the forum. Nice write up. Used to see folks going the other way from EFI to carb.
Thank you! I did a TON of searching before I started this project, and I really only found one post that was similar and a bunch of questions with no answers, both from 10+ years ago. In case someone wanted more info on this not-so-common project I wanted to make sure the information was out there.
Last edited by rhyino; Mar 4, 2024 at 10:12 AM.
Reason: added quote
Hello everyone! This is my first post and I hope it helps someone who might need it!I wanted to do a quick write up since I havent seen much on the project I just completed. I have a 2005 Road King (FLHRS) and I just finished converting it FROM carbureted TO Delphi EFI. Why? Because I wanted to. So I guess now I have an FLHRSI.
I ran into a few small issues along the way that Ill explain, but overall doing the conversion went pretty smoothly and was just time consuming. I have made a parts list of everything you would need at bare minimum to get the job done. Next winter Ill be building the motor so I went with an HPI 51mm throttle body, an HPI air cleaner, and a Thundermax tuner but you could just go with the factory Harley stuff to save some coin.
I have the fuel tank from the 05 models that can either be EFI or carb so the swap there was easy. I just got everything needed and assembled the tank. Removing everything for the carb (fuel level float and top plate, petcock) and installing the EFI stuff (fuel pump, fuel lines, Quick Disconnect line). I ran into a few issues regarding the fuel pump top plate and the wiring harness, but you can read about those below.
Once the new-to-me harness was run, the throttle body was on/connected, and the tank was put back on I put on the air cleaner and got the dash set up (which I had some issues with see below). Then I primed the fuel pump a few times, plugged in my laptop to the Thundermax, loaded a base tune (from Shop67), and then fired it up. It started right up with no issues; all my readings were great on the Thundermax tuning software, and the throttle was extremely responsive. Im currently running the auto tune before I plug it back in, but everything seems great. Gone are the days of messing with the choke and throttle to get it to start, then letting it warm up for what seemed like forever. I can just get on and go!
I did a few other maintenance things while the bike was in pieces that arent necessary but since I had the tank seat and bags off, I figured why not. I installed Fueling head breathers, ran new throttle and idle cables, flushed my brake lines, upgraded my rear suspension, replaced all the fuses in the new-to-me wiring harness, etc.
Now onto the issues.
The first issue I ran into was routing the EFI portion of the wiring harness. The main part of the wiring harness was pretty simple. I started at the bars and cut/replaced clip ties as I went, unplugging things from the old and into the new and followed the original routing pattern. I got the main section fully replaced and then realized I had a whole new section of harness for the EFI stuff. Eventually I found an online version of the service manual and with the help of some photos from friends I got the harness ran properly and connected my Thundermax to the EFI harness and on the EFI version of the ECM bracket.
The second issue I ran into was the lack of bolts for the sensors on the throttle body. I ordered an HPI throttle body and all the sensors I needed. Since I did not have a throttle body to begin with, I did not have sensors or bolts for anything to re-use. Of course, none of the sensors come with bolts so I had to source the bolts I needed to mount the IAC sensor and the Throttle Position sensor to the throttle body. Your best bet is to use a tap and go to your local hardware store. I went to three different dealerships in my area and none of them could tell me what bolts I needed.
The third issue was the top motor mount. Apparently, Harley made the top motor mount bracket different between the EFI and Carb versions of the bike. The line running from the gas tank to the injectors did not fit with the carb version top motor mount. There is a significant lack of bend in the mount to allow that line to fit underneath and be routed like its supposed to. Once my correct mounting bracket came in the line fit with no issues.
The fourth issue was the fuel pump harness. To save some money I purchased a fuel pump from an 06 touring bike. It was about 300 dollars cheaper than anything I found for the 04-05 versions, and since I was going to rebuild everything anyways the condition of the pump and associated pieces was not important. After I had everything installed on the rest of the bike, I went to plug in all the connectors for the dash and realized that the fuel pump connector on the harness is a rectangle three-pin connector and the female end on the fuel pump plate is an oval four-pin connector. I ordered a short wiring harness meant for that fuel pump and then cut the three-pin connector off the harness and wired it into the new four-pin connector. The fourth pin is a second ground (according to the wiring diagram) and is not totally necessary, so I just capped the wire. The fuel pump primed right up with no issues once the connectors were good to go.
The fifth and final issue was the bracket that the dash bolt slides into in the fuel pump top plate and then the nut tightens down on to hold the dash in place. On my original fuel pump plate the bracket is located at the bottom. However, on the new one the bracket is in the middle. I tried to install the dash but there was no way the bolt could go through the dash in its current location. I ended up finding a piece of Din Rail at my work that worked perfectly as a bracket for the bolt. I cut a few pieces off and trimmed them down to get a flush fit, then cleaned both sides and used a metal bonding agent (JB weld, Loctite, epoxy resin) to hold it in place. So far so good, its holding just fine.
Let me know if you have any questions. Ive included some photos for refence
Hello everyone! This is my first post and I hope it helps someone who might need it!I wanted to do a quick write up since I havent seen much on the project I just completed. I have a 2005 Road King (FLHRS) and I just finished converting it FROM carbureted TO Delphi EFI. Why? Because I wanted to. So I guess now I have an FLHRSI.
Excellent post and work! I'll book mark this one as it's outstanding information.
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EFI conversion from carb on an 05 FLHRS
