I was catching up on some stuff on YouTube and was watching a video by DK Customs. If I understood it correctly with an M8 you can run a free flowing air cleaner and exhaust and not really need a tuner?
Just seems like the bike would get too lean.
Anyone know about this?

 

That's called a stage 1 from harley and they do include and recommend have to re tune the bike when adding exhaust or AC other than stock.

 

Depends on the bike. What year and model?

 

do you want your machine to run and perform optimal? then when changing the OEM parameters such as performance exhaust and intake hardware retuning is prudent and wise..and may also make it safer to operate without damaging the internals..the cost of a proper tune is more beneficial than all the chrome doo hickies and farkle sparkle that so many spend money on without thinking twice about

 

2020 Road King with the 107.

 

If you are changing from stock, then, you are changing the performance of the bike. You are going to get more air, etc. It would stand to reason that, all other things aside, you are changing all this for performance-and, if the ECM stock is dialed in for stock parts-putting aftermarket parts on there-even the SE stuff-is going to change the performance of the bike.
So, yes, you should be tuning it. I dont think that NOT tuning it if you change slip ons and air intake will necessarily harm the engine (provided you dont do anything else)-but it WILL run crappier, as its no longer set up correctly.

As an aside, if your engine does grenade, because you didnt tune after putting those on, thats on you-I am in no way liable for any advice I may give, or you may take.

 

They come lean from the factory. I would prioritize a proper tuning device over exhaust or air cleaner. Check out Fuel Moto. There's a lot of posts about tuners here but in my opinion, the powervision is the best one.

 

Some ppl want to retain factory warranty....

 

I've yet to find someone posting the stock M8 AFR tho. Everyone says "they're lean" but no one will show me.

As to tune - with slip ons, I'd not fret at all. With A/C changes - likely would. Then again, no one's been able to show what a stock a/c flows for air vs the supposed more "free flowing".

I'm sure the data's out there - I just haven't seen it yet. Again, not talking HP/TQ but afr and cfm etc.

 

Yup.

I took delivery on my 17 and 1 week later added S&S mk45 slip ons. No tuning was mentioned or recommended. Only when I did the stage 1 and swapped AC's did I get the tuner and re tuned the bike.