Looking to see how much power everyone is putting on their stock bottom ends with a big bore kit . Looking at a 124 kit and possibly heads and a tb later on. How many miles have you put on your setup? At what point should one start looking at darkhorse for welding, pining, balancing, and truing? How long is the life expectancy of main bearing?

 

I have a 2017 RGS that I built into a 126ci that makes 160HP and runs on pump gas. 10k on the build. I don't abuse the bike but I do use the power. I have no worries about the crank but clutch basket, compensator and transmission are week points. I don't think these other components could handle the power doing full throttle shifts and such. A good friend has a 2019 CVO Road Glide with a built 130ci making 163HP and runs on pump gas. His build has 21k+ on it with no issues. IMO if you're going to build a high powered big cubic motor and plan to beat on it, then the crank would be a good place to start as well as the other components I mentioned and possibly a chain conversion.

 

I discussed it around here, and with the very few guys that knew anything about M8s in my area, and tried to keep the numbers at max of 130hp/150tq to keep the transmission alive if I do my part.
I had already been down this road, breaking things, and did not want issues out in the middle of nowhere, thousands of miles from home.
Not one person EVER mentioned issues with the bottom end, so I felt relatively safe. I intentionally left the heads alone, and stayed with the torque cam I had chosen for the 114. It put down 123/149 on the dyno.
So far, I have 13K on the 128, a total of 15K on the bottom end. No issues, no leaks, no transmission problems. I TRY to pay attention to full throttle upshifts, and control my clutch hand

I change the transmission oil early with the engine oil. Just trying to give it every chance.

 

Its torque that loads engines. The compensator will be the first to go, I make a tool steel one that won't break. Then the clutch basket, if that fly's apart it will kill everything in sight. It destroyed my motor. Parts got stuck under the alternator and split the crankcases. So I made billet baskets as well. If you want to play you have to pay. It's the game we are in.

 

What Joe said is 100% correct.

I use the power, but do not do burn outs. I do not beat the crap out of the bike. The week links are clutch baskets, belt, compensator and 3rd gear.

I absolutely love all the power, and do use it, and do ride it. 21K since built in 9 months.

 

I hear that, I usually do one big trip a year and don't want any issues. This year I'm going down to ride the tail of the dragon and do the Iron butt challenge in one swoop. I don't want to be the reason we can't complete that. The heads and tb aren't in the cards for me this season anyway. I have the 22xe cam and about to order up the bigbore kit. Was looking at aim lockup clutch with stock basket but now am considering something else. Is your compensator and basket stock?

 

I beat mine pretty hard, 128 at 2000 miles, fuel pump in the middle of Kansas at 7000, then cleaned 3rd gear off at 11000. Just put a gudgebox in and welded the comp with 61 miles when cold set in.

 

Welding the comp up will beat up your primary chain, tensioner and starter, gearbox and drive belt. That V twin motor gives everything a hard time.

 

So far, yes. It is on my list, but I blew all my money on Ohlins shocks, and TrueTracks. I do have the AIM SDR

With the stock TB, you aren't going to hit any big numbers, so you would have to abuse it. I think you will be just fine! Don't sweat that basket and comp. with that setup

 

I’m following along with this discussion. I have a Fuel Moro 128” build with their Level A heads. It dyno’d at 153hp/151tq.

I don’t ride all crazy, but I do enjoy my newfound power. The only downstream parts I worry about are the clutch basket and transmission. I don’t expect either will be a problem, because I really don’t beat on this bike. Still, I have started looking at clutch baskets and for a little over $400, you can pick up a billet aluminum basket from Barnett. Just need to swap the ring gear and add a bearing.

But, like you NorthWestern, I ended up buying Legends suspensions front and rear...might leave these parts to tend to at a later date.

It never ends!!