I had swapped the 117 CVO motor when the bike had 9k miles on it back in late October, I just clocked over 14k miles with my recent 2500 trip to and from Daytona. I have ridden this bike in winter temps, 80 degree weather, sustained high speed runs, in steady rain, bumper to bumper stop n go traffic in some accident traffic on I95 plus of course bike week craziness on main street. Havent ridden it in high altitude Rocky Mountain type terrain yet. Its an all harley crate motor set up with a harley factory tune for the selected components. So here are my impressions:
1. A super tractable motor to ride. When you want to go easy, its happy to put around. Letting go of the clutch at idle, you really dont need to give it gas to get rolling.
2. A vicious motor to ride if you wind it up, strong from idle but a whole another gear once you hit 3000 rpm and keep going. One of my riding buddies on a newer cvo with the 121 factory motor was trying to mess with me at a stop light on a straightaway. It wasnt even close, lol.
3. Was happy to not have any heat issues with the twincooled motor. Even in the extended stop n go traffic, it was never excessive. I could feel the motor getting warm air on my leg at an extended idle stop but never excessive. The 131 I had on my 2017 cvo would have burned my leg off in the same situation.
4. Gas mileage is definitely off a bit from the stock 117 motor. I could easily get 42-44 mpg in high speed riding, I consistently got 38-40 mpg with the 135.
5. I can see an inexperienced rider getting in trouble with a motor like this with the injudicious application of throttle in certain situations, I can also see a conservative rider being happy with it without ever coming close to tapping the power this motor generates above 3000 rpm. Really upto an owner to see if the investment is going to be worth it to them for how they ride.
Some final thoughts, high volume dealers are really trying to push this motor now as an ultimate upgrade. At Teddy Morse HD, I saw atleast 5 or 6 2025 bikes on the showroom floor where thet had sapped the stock 117 motors. Interestingly, all their cvo 121's were untouched. Personally, for me it was worth every penny to upgrade my 2022 cvo roadglide limited. It gave me a powerful, reliable ride that i will continue to enjoy for several more years.

 

nice that the 135 comes with all their best SE parts..except now you just need this to complete the package..c'mon, you know you want to

https://www.harley-davidson.com/us/e...ion/p/36300037

 

I read a lot of good things about the 135. I have contemplated it for my 121. However I really want to keep the VVT. I'm guessing in less than a year there will be a way to do a 135 and keep the VVT.

 

Certainly a big improvement over the 117 and a lot more fun.

 

you know if I felt the need for it, I would do it. The stock tranny is fine and the clutch pull even with the stiffer springs is good.

 

You should definitely come back and give a 10k or 20k review as well. My impression is that people are wary about the longevity and long term reliability of the package.

 

I figured as such, just that one of my favorite and least expensive pastimes, is trying to spend other people's money

 

I will for sure. I should be close to 20k by end of 2025.

 

Great review. I would love to have one, but just haven’t seen the need for more power to justify the cost. It sounds like the perfect engine package.

 

If youre going to keep your bike for few years, its worth it. Specially as you ride 2 up much of the time.