I have a 2010 FLHTK which I have put lots of money into to get her where she is with cosmetics and Audio. However, when I got her brand new I added FM Air, ceramic headers, V/H monstah rounds, 555 cams and a t-max unit. I really love the bike but after four years I was wondering could my rode sofa go any faster, so I started doing some research.

I've read a lot on here about the 120r motor, big bore kits, crank issues and all the stuff that goes along with it. I have about 5 grand coming to me for motor mods. I am thinking about a big bore kit and changing the cams to something more aggressive, but I do not want issues with the crank later down the road.

What are you Big Cubic engine guys running and can I get a super power increase with reliability for 5K?

 

107 Kit w/the crank welded, trued, and balanced should suffice I would think.

What are your numbers now?

 

If you use Search for '120R' you will find there are not that many threads, also they cover other options, like the S&S 124". Consider the economics of using one of those new engines, then selling yours, as a way of off setting some of the cost. That might just come within your budget! A 124" kit costs around 6k......

 

Call Fuelmoto, their 107 build with the new beefy IC jugs and B-heads is not too bad, and you already have the 555 cam, which I assume is a Woods cam. Have the crank welded and trued, & install some go with the lefty bearing which is a Timken i think....

 

I am a fan of S&S products - u can get a 124 crate for 6k offset by selling your current motor and its well within your budget

 

Yes, get the S&S, if not you need to get your crank trued, with what you want to do the stock crank will slip

 

If you go for a big inch you need to also worry about a clutch upgrade.
I bet for $5k you could keep your cams install the FM 107 with B heads and maybe a SE heavy spring for you clutch and you would be grinner from ear to ear for at least another couple years?
Also if your ceramic headers are a 2-1-2 or true dual you would be wanting a good 2-1 for a big inch engine that needs to breath, I'm learning that the hard way!

 

If your thinking of pulling the crank to update why wouldn't you also get it clearanced for at least 110ci. I always thought those 106-107 kits were for guys to didn't want to tear down the bottom end.

 

I would go with the fuel moto 107 inch kit and not look back. I have a friend with one on his road glide and he will walk away from most of the "big motors" he comes against. The key to that is a good tune, good exhaust (2 into 1 is what seems to be popular), and some skill. The bigger motors are nice but do you really want to have to upgrade the clutch and transmission to go with it? I would rather put that money where it belongs, in the fuel tank.

 

124" and run at the front of the pack