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Proud owner of a 103 ci 2012 Limited that I've had since new. Its had cams and tensioners replaced and a stage 1 done. I got some money when my mom passed recently and I'm thinking of a stage 4 upgrade. The only kits I can see for 103 ci is an upgrade to 110 ci. Just wondering if anyone has done this to their ride and if the change in performance is worth it. Also would be interested if my 103 could be upgraded to 117, if anyone knows if theres a kit for that. Thanks in advance.
Proud owner of a 103 ci 2012 Limited that I've had since new. Its had cams and tensioners replaced and a stage 1 done. I got some money when my mom passed recently and I'm thinking of a stage 4 upgrade. The only kits I can see for 103 ci is an upgrade to 110 ci. Just wondering if anyone has done this to their ride and if the change in performance is worth it. Also would be interested if my 103 could be upgraded to 117, if anyone knows if theres a kit for that. Thanks in advance.
FWIW...
FuelMoto offers both 107" and 110" big bore kits for your bike. Their 107" kits have been pretty popular over the years, with a lot of positive feedback from those who used them. They seem to be good for a boost to a touring bike, more than trying to turn your bagger into a performance bike.
FuelMoto used to offer a 103" to 117" big bore kt. IIRC, it involved separating the cases and some machine work. It was a special order big bore that they required that they installed. I know of one person who went that route, had an undisclosed issue that was remedied by FuelMoto, but then FuelMoto stopped offering that upgrade.
I was looking seriously at that 117" kit for my '16 103" air cooled Ultra Classic. Instead I went with their 124" S&S crate engine.
I love the power & torque of that 124" crate engine (135HP/151TQ) and have put 23K miles on it touring around the country. I was, and still am, a big fan of that mod...
But recently I found one big "wart" on that 124" S&S engine. I had a rear cylinder base gasket leak. What a pain to repair....
First, the design/hardware of the S&S heads made it so I didn't think I would be able to repair the engine in frame. Until I received some tips on another technical forum, I couldn't get the rockers out of the rocker covers to continue the repair.. With some guidance, a special S&S Rocker cover wrench set (@ $130.00), plus finding a local S&S dealer that could order the S&S parts I needed for the repair (many of the small parts aren't on the S&S web site, available ot dealers only), I got it done. But the room was very tight. Not a fun job. IMHO, it was more expensive and harder to do that repair on the S&S engine in frame, versus a couple HD Twin Cams I've worked on...
I suggest you find a good shop, with a good reputation, in your area. Tell them your goals, and let them guide you to an appropriate mod... whether they sell you the kit for DIY, or they install the mod for you... Most good shops have proven big bore mods, with parts & pieces that compliment each other, that they have had good results with...
Good luck with your decisions and your mods...
Last edited by hattitude; Mar 12, 2025 at 03:07 PM.
All so far are good suggestions. I did the Harley 103 to 110 kit because I do not do this work on a regular basis. The kit was a simple parts replacement and reprogram with the SEST tuner. The increase in torque to pull the big bike off the line was worth every penny. Unfortunately, that bike was totaled when a cage blew a red light. I recently purchased a replacement 2013 FLHTK and I am considering the same installation, maybe next winter while the bike is sitting.
My 2015 Ultra Limited had a 103 Stage IV kit on it, Swapped the Screamin Eagle High Flow exhaust for the Vance & Hines stainless steel 2 into1 pipe, Bike made 117 HP and 109 ft.lb. torque, lots of fun to ride.
HD stage 4 kits leave a lot on the table. Since 96/103/110/113/117 all take the same flywheels, I'd bore the cases, have Darkhorse rebuild the flywheels, and use the S&S 4.125 cylinders & pistons, and WFO Larry ported heads. All new bearings, cams to suit your riding style, and enjoy for another decade.
If you can find a set of take off CVO heads, the 117 really shines.
This is my kids 117.
Last edited by rigidthumper; Mar 13, 2025 at 09:07 AM.
Proud owner of a 103 ci 2012 Limited that I've had since new. Its had cams and tensioners replaced and a stage 1 done. I got some money when my mom passed recently and I'm thinking of a stage 4 upgrade. The only kits I can see for 103 ci is an upgrade to 110 ci. Just wondering if anyone has done this to their ride and if the change in performance is worth it. Also would be interested if my 103 could be upgraded to 117, if anyone knows if theres a kit for that. Thanks in advance.
Really? That's what your mom would have wished for you to do with the money?
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Stage 4
With some guidance, a special S&S Rocker cover wrench set (@ $130.00), plus finding a local S&S dealer that could order the S&S parts I needed for the repair (many of the small parts aren't on the S&S web site, available ot dealers only), I got it done. But the room was very tight. Not a fun job. IMHO, it was more expensive and harder to do that repair on the S&S engine in frame, versus a couple HD Twin Cams I've worked on...
