WATCH THIS BEFORE YOU UPGRADE TO A 124 OR 128 BIG BORE KIT ON YOUR M8 HARLEY DAVIDSON

[@kevinmorris701]

Please do some more homework on the topic. Stock 107 and 114 motors have a 3.937" bore. S&S kits do not gain cubic inches by deck height. S&S kits increase the bore to 4.25" for the 124" and 128" kits. Harley 128" and 131" kits increase the bore to 4.310". The jugs are the same in all of these kits. The piston pin location is different between the 4.375" and 4.500" crankshafts.

[@berndbecker1001]

At least one who doesn't talk nonsense. Greetings from Germany

[@jjs8046]

@@berndbecker1001exactly. I'm shocked how little people know and mislead other. Greetings from Poland.

[@HolgerDanske89]

I knew I could rely on the comments to straighten that out... literally no difference between the 124" and the 128" they both use the same cylinders and pistons at 4.250" only difference is you need the 4.500" crankshaft to hit the 128" otherwise with the 4.375" crank will only get you to 124" they definitely messed up something else.. there is absolutely no problem with putting the 128" in your 107" I know many who have without issue. S&S also now makes a big bore 129"/136" big bore kit that uses a 4.320" piston.. which makes 129" with the 4.375" crank and 136" with the 4.500" crank.

[@dt8587]

@@HolgerDanske89 so i can put a 128 s&s kit onto my 107. But it will only come out to 124?

[@Fly1Style]

@kevinmorris701 The information in this reply is wrong. The stock HD 107 and 114 have a different bore size. You can check the owners manual or just Google it.

[@billmart67]

I have a 18’ road glide special,came with 107. The performance shop went to put a 128 kit on my bike. I have 6k miles on motor, runs like a champ and has big power.

[@breez9979]

Thank you for this. I was going to do the same thing to my bike , you saved me a lot of time and money and headache .

[@brentbandy3566]

Great info. I can’t say enough good stuff about Fuel Moto. I called them about taking my 107 street bob to a 124 and they walked me through three different scenarios, step by step and were completely patient and thorough when answering all of my stupid questions. I’m sure S&S is the same way but man, Fuel Moto seems to have it figured out. Thanks for the awesome info!

[@GregCarter-r1v]

Fuel Moto good!👍

[@raybrdjr]

Great subject, John! I actually called a shop last week and asked why i couldnt put a 128 on my 107. They said the same thing, because of the crankshafts are different. Good info my brother!

[@swiss9632]

I found you through Pay-it-forward. I ride a 2016 SGS. I have been riding since 1968. Less 20 years due to kids. Then started back up in 2003.

[@brianmaclennan561]

Ive got a 18' rks with a 107/128 se big bore kit, stage 3 cam, full rinehart exhaust, bigger se manifold, injectors etc, been fitted for 2 years now an done 38,000 kays, bike goes hard af an zero issues....🤷‍♂️

[@payogie]

Just rode the Tail a few times this week. I 2nd RG114, "do not take your eyes off the Dragon". It's 11 miles of pure fun!

[@gnd111]

Soooo many challenging and more fun roads up there...

[@TheSmokeychris2000]

I feel kind of bad for the guy. Because he got exactly what he bought. They sold him what he asked for. So a big part of this is do research before you buy things. Know what works with what. And ask questions. Big numbers don't mean better if your bike don't run

[@DackRedd]

So true. 58 and been riding HD since 16. If you go in and order something specific and talk like you know what you are saying, they will get you what you ask for. In no way was this the s&s or harley dealers issue. I know exactly what I want but I always ask one of my friends who works at a dealership as a parts guy and one of my friends who is harley certified. Then again, I grew up, fixing my own stuff. Quite honestly, if you take your time, bag each bolt or bolts in an assembly and label bag. Take plenty of photos. I can't imagine being on a bike I can't fix it. The whole breaking down and being able to fix it is part of the journey

[@Henry.58]

Stage 2 is as far as Im going with my 103. 2014 it seems they had all the bugs worked out of that Motor. I'm happy with mine ,but after watching your previous Video about upgrades ,a Stage 2 is good for my style.

[@19jody72]

I put S&S 585 cams, fuel motor x pipe, thunderheader slip on, Tuned..101/111. Stock compression..runs like a raped ape and I've put 30k HARD miles in it. Don't need anything else.. every thing else is just to brag about hp/tq that you have and it will over heat in summer running the shit out of it. Mines a 14' street glide as well.

[@BobBob-fp5fn]

If you want a 127ci for a 107, tman performance makes a 127 cylinder and piston kit for 107 m8s. The cylinder walls on the tman are thick also. It just costs more money.

[@jasoncarboni3682]

T-Man did a 135ci on my 2019 RGU. I was actually his first 135 build back in March. Incredible machine now!!! Highly recommend anything from T-Man

[@BobBob-fp5fn]

@@jasoncarboni3682 I highly recommend him also, definitely one of the most knowledgable ones in the industry and his products are fantastic. Everything from him is nothing but high quality.

[@gauravLDH]

Thanks You for the precious information 👍

[@gpcbr1000]

Greg Dull , who owns GMS Racing engines in Uniontown Pennsylvania is one of the best! He did a 128 out of my 114. People sends this guy engines from all over the world. And his prices are very fair

[@hookdog8640]

I glad to see someone else being honest with people. I get tired of seeing people get ripped off. Then helping them fix it. Some shops need to be put on blast because they don't care. The shop should of eat the parts and labor. So he could of went else ware.

[@nickmcelroy2195]

Can’t wait to meet you on July 17th! You’ll love East TN! Safe travels my friend!

[@jamescruz7460]

John, off the hook, good locking out. Kudos to Dave, he is the man. I had my front suspension done in May with Dave. Great experience.

[@randywheeler3914]

I'm glad I found this video I am researching Big Bore kits at this very moment for my 2017 Road Glide Special saved me from possibly making a huge mistake

[@jerrydouglas8458]

I did the stage 3 on my 18 107 RGS. H-D tuned it with the Pro Street Tuner. I have since changed out the cam to. Woods 22X and tuned it with PV. The changes are impressive. 120 TQ and 115 HP.

[@randywheeler3914]

@@jerrydouglas8458 I've been looking at that S&S 124 kit and the Fuel Moto 124 kit

[@mojomanmurph1925]

I did a HD 128 Big Bore kit on my 2017 Street Glide Special, including upgraded oil pump and clutch+springs, HD Pro Street Tuner and Smart Auto Tune. Fullsac header formed to be able to use the factory heat shields with V&H 400 slip-ons. Put 10,000 miles on the engine already and running great. A torque monster and a blast to ride. Why I went with HD 128 kit is because they designed the engine, they should know what a good combo would be without issues as mentioned in this video. I have been to many dealerships and that one as mentioned in the video has some idiots working there. If you want stupid fast, go watch some Moonshine Harley videos. Research and be educated before you pull the trigger.

[@randywheeler3914]

@@mojomanmurph1925 whatever kit I do with whether it's S&S Fuel Moto or zippers I would like to take it and have it Dyno Tuned by whoever I buy the kit from just don't know which one would be best decisions decisions

[@jerrydouglas8458]

@@randywheeler3914 I can only say that I’ve been happy with the PV, cam, lifters and other parts I bought from FM. They have also replied quickly to my emails and request for support.

[@rolandb.campos4535]

My opinion save your money an go only to stage two. This bikes are cruisers to relax not to race.

[@robertdavis5495]

Agreed but when riding two up with close to 500 lbs with luggage/gear, having 150lbs of torque from a properly built big bore kit is a blessing. Going up long hills with steep inclines is a lot easier. And I emphasize a properly built motor not Frankenstein race motor

[@simonholm2291]

Feels a heck of a lot cooler going fast on a Harley 😂

[@trekbsg]

Do you mean compression height, not deck height? I'm pretty sure the deck height is the same on all factory M8s from 107-117ci, the deck height is measured from the centerline of the crankshaft to the top of the cylinders. Compression height is measured from the centerline of the connecting rod/wrist pin to the top of the piston. When a change of stroke is made most manufacturers will design a piston's compression height so that the piston will reach top dead center at the top of the stroke or they'll install longer or shorter connecting rods to make up the difference.

[@chrisbowers2355]

With the right piston with a raised pin locating

[@ejdtm]

It’s sad that the dealer didn’t know it was the wrong kit. I’m gonna try to head down for that weekend.

[@actfitwil]

The 124 and 128 are the same kit besides the piston. The only thing he has to do is put in the correct piston. Wish I could meet you guys at bootleger harley, seems like a lot of fun.

[@ridefitnation]

Excellent example explanation John. I’m getting ready to do a 124 kit on my 107.

[@richardbandolik1503]

How do you like it? I was thinking of doing the same. I currently have 95k on my RGU. Did you change the flywheel?

[@michaelwilson4612]

Bro u just saved me an ungodly amount of money and headach.....thanks a lot!!!

[@wingandhog]

I have my Electra Glide with Stage 1 & 2 and love it and will always keep it, this is Harley #6 for me. But in all honesty, some of this stuff is why I decided to buy a stock 6 cylinder 1800cc GoldWing and just be done with it. No performance upgrades needed as I rocket down the freeway.

[@duanesmith5074]

Well I didn't jump on a wing but I did jump on GTL

[@434srt90]

I remember that weeks of 105, rode everyday to work in that heat, but fried my engine from the heat and still have problems, but will be doing the 128 if engine doesn't get fixed, sounds like someone either didn't know their engines or what

[@victorpio2459]

Appreciate the information homie , as a new rider don't alot , my next bike will be a road glide with a zippers 124 kit , its Thanks to people like you , and Traveling Tall , I have learned these things 😊

[@rcjones75]

Might as well throw a Trask turbo kit on and up the boost to compensate for the low compression

[@michaelwilson4612]

This video helped lots of people, including myself.

[@kevincraig8257]

my 117 stock pulls good enough for me I'll stay away from the hop-ups

[@eddierodgers8]

Hey man thank you for all the information man I'm remember that man I'm very happy that you have sat down and and talk to us about that

[@nevillegreg1]

Judge Judy will sort the dealer out for suggesting and installing the incorrect kit for the 107.

[@tax905972]

He probably wanted the aftermarket kit, after following behind others.

[@stevemolina8801]

Good video, many when doing upgrades dont do their own homework. And another reason I don't take my bike to Harley, most of them really don't know shit!

[@haroldmatson3908]

124 and 128 are the same but for 2 parts. The pistons. BTW 128 will also fit a 117 CVO.

[@patrickstevens5457]

Actually the cubic/in gain is from bore increase on both. The difference in height between the two is to keep compression.

[@RobertJones-ix2hu]

The meet and greet y’all are doing is awesome! Good folks giving back to their subscribers! Really hoping I can’t make it!

[@rschris]

Another awesome video, brother. Yeah man I feel for Rocko being in that situation . Thanks for passing the info !!

[@johne6525]

GREAT INFORMATION I DIDNT KNOW!!! Thank you John 🤙

[@ramseydiesel5952]

If you’re low on compression from that just pull the heads and put some dome pistons in it to up the compression def measure to make sure you’re not going to hit valve but that’s a lot cheaper than splitting the cases

[@industryousphotography2058]

S&S makes this clear on their website. Scary that the mechanic couldn't read the instructions on this product when ordering.

[@VeteranBiker]

I just watched this whole video and wow!

[@EMAC1168]

Thanks for this video!...Very informative! Looking forward to meeting you at Bootlegger HD.

[@xpresident]

Harley Davidson should pay to have his bike changed over to a 124

[@kobyashi73]

great information. Exploring this very upgrade for my bike......

[@GregCarter-r1v]

He should have done his research. The 128” Screaming Eagle motor stage Four with 4 /5/8” flywheels and upgraded oil cooler that’s recommended specifically and warranty through HD would have been a better choice. After the warranty expires, he could go re- cam it for a little more horsepower. That’s what I did with my 2021 SG 107”. Cheers!👍

[@BadazzShovelhead]

Great video thanks- I gotta say there really is a problem with dealerships and builders responding to folks. I am an exec in Silicon Valley but have ridden Harleys all my life come from a Harley family- My gramps used to race them and all my cousins etc are bikers. Anyhow, I got lucky after the USMC and got a job that has gotten me to exec level at a huge tech company in Silicon Valley. So on occasion when I want a new bike, I call, leave messages, or mostly send emails so I can give an indication of what I want done. I run global cyber intelligence and investigations so I am constantly traveling overseas- If I had time to build I would. You'd think a builder or a dealership (here in California) would be itching to build a no holds barred bike with a nearly limitless budget. Especially with all the whining the motor company does about losing market share etc. Start treating long term customers who spend a ton with you with some respect. There was a famous dealership here in this area and they acted like they were doing you a favor selling a bike to you or a part. Which is probably why they went out of business. Gigantic showroom and if there were customers in there it was mostly tourists buying clothing. Sorry for the rant but when you mentioned the guy wasn't getting responses it hit a nerve. I did finally find a guy who not only builds incredible bikes and even when I am overseas I'll send him a text and I'll have a reply within hours at the most- hustles his team hustles and he delivers what he says he will deliver.

[@aarondr69]

It’s good that they admitted foolt and I’m glad they cooled Dave on the phone

[@stevebonnesen2272]

a lot to be said for being happy with what you have... and a lot to be said for going mild over wild for street use... if you go big expect big problems...so be sure and have a wallet to match... ..no whining..no sniveling...

[@iceman2520]

Thanks for the info 👍🏻I'm planning 128 for my RGS

[@MinnowMoto]

I agree with you about the heat outside. Its Crazy hot. You explained that perfectly. Thanks for getting all that detail together. I would have though a dealer would have known better.

[@doraexplora9046]

I looked it up. 110F is pretty hot. But on a moving bike, it's actually a pretty good temperature. Just jump off the bike at the end of the ride, as soon as you humanly can and don't get back on, until the whole thing has cooled right down. OH. and for God's sake. Park in the shade! or stay at home in the A/C and the pool.

[@asoward88]

Do your research!! ‘Nuff said.

[@benjaminconnolly5655]

You CAN do a 128" with a 107 engine, you just have to replace the crank with a 4.5" rotating assembly, which costs $$$$.

[@chestercalloway3812]

Deck height has no effect on cubic inches. It comes down to stroke and bore, not deck height. More deck height without changing anything else just lowers compression ratio.

[@pharaohnile867]

Thank you . i have 117 stock M8 motor 4.5 crank .I was gonna get the 131 kit im not sure if it would work since the 114 and 117 share the same 4.5 crank .you just said the biggest you can go with a 4.5 crank is a 128. So il be getting 128 kit . Thanks for the info you saved me some money👍

[@dconte24]

you can go 131 on the 114 or 117

[@phillipcabaniss5028]

Man, I can’t believe a tech or a shop wouldn’t know this!

[@darrellwilson7734]

This information makes me feel a lot more comfortable

[@ocglide2566]

That's a huge mistake by a dealership. They should have known the 128 needed to be installed on a 114 not a 107.

[@FatbobRell]

@@ib12541 believe it. Harley will install anything on a bike if requested. They will increase their labor rates if it’s not a Harley product.

[@ronwhite1642]

Different piston is all 👌

[@FeatheredDino]

@@ronwhite1642 There's big differences between the 107 and 114. They actually have different engine castings.

[@ronwhite1642]

The stroke is different and the piston is the difference same everything else 👌

[@ronwhite1642]

The only difference from 107 and 114 is the 107 flywheels is 4.3/8 and 114 is 4 1/2 👌

[@TheRichvw23]

Just a piston swap; the wrist pin height is different. I believe the Harley kit is 127 for the big bore kit for a 107.

[@Ed.Johnson]

I don't know how many 124/128 kit combinations S&S has, but I believe you are correct, it's just the pistons and wrist pin being different. If the dealer admitted to being wrong, why didn't they correct it for him?

[@dennisknoblauch4700]

Its boiling balls up here in Pa too. Sucks for Rocco. I was wandering about him. As soon as you said 107 i knew where you were going. Thanks for the update.

[@dennisknoblauch4700]

@@CYCLEFANATIX its running great. A little hotter than a standard exhaust. Spending alot of time on the boat to beat the heat right now.

[@NoName-xf2nf]

Great information John how is the rider who lost control of his bike doing

[@NoName-xf2nf]

Thanks John for getting back to me on your friend and John are you Italian

[@philmarquez8707]

Thank you this makes another something I had no idea these things that can happen with my new 2019 107 lowrider...

[@redrider0151]

Great information!! Love your channel!! I found your channel via Tall's ride....got a new channel to binge watch!! :D

[@smoothsam7]

Thank you for very very valuable information I do watch your videos keep us up

[@h3r63rt]

🥺. What I learned from this is “Dave is the man!”

[@bigjohn860]

When you go to a Harley Davidson Dealer, your lucky if they put your tires on correctly. or torque nuts, bolts correctly, same goes for any Automotive Dealership. Its all about the Money.

[@20sgcvo90]

I would tear it down split the case throw in the right 4.5 stroke crank maybe use dark horse crank and put it back together.

[@joesainato8051]

Was wondering what happened with Rocco’s bike. I would of put the correct 124 on it. He has all the other parts already. Dave was into it so labor and kit wouldn’t of been too bad. I also would be raising all sorts of hell with the dealer till they refunded me or bought me the proper kit.

[@SJJsolomonSJJ]

Can not wait for this upcoming road trip video🙌🏾🙌🏾🙌🏾🙌🏾

[@ncautolink]

Very good information and explanation! Great video!

[@lilbroinarizona4315]

124 kit and 128 kit have the same bore. The ONLY difference for cubic inches between the two is stroke. Deck height does not change engine size. Only bore or stroke.

[@harleyhawk7959]

three days of consecutive temp records. 105,107,112. my home town in western Washington. has never been that hot ever.

[@smoothsam7]

Thank you for them gems I’m going that way myself

[@markroy7366]

You can do this but you must change the crank shaft and rods to do it correctly

[@scottschaeffer8920]

I get it but, my 107 has more than enough power for me stock. I know, it’s a personal choice.

[@normanmatura6769]

Or deck the heads pull the jugs cut the bottom of the jugs to make them sit lower and then Reese see down the heads and check the compression and tolerances

[@21Fxlrs]

Is your fairing and fender wrapped?

[@joefrias]

Hey, found your channel. Nice info to know - Joe from South West Texas.

[@gezimrexhepi8356]

If you have 114 best to go is at 131 from screaming eagle HD no issue .(I would love to meet with you ) you are in the neighbourhood I’m in GA

[@bigross0318]

i feel like the dealer/shop should have seen this when ordering it. even on the s&s website, it states 107-124 OR 114-128. that dealer/shop should accept some responsibility and make it right. even help him with the labor or parts or something. a couple grand aint gonna affect a big shop vs a regular person. plus it shows that even though they made a mistake, they made it right.

[@yungstasidewayztonganharle8426]

If you buy the 128 cyclinders from Harley Davidson. The 107 crank will work and you will get the right compression.

[@yungstasidewayztonganharle8426]

And it’ll be a short stroke 128

[@brody5563]

They don't make domed pistons or pistons with different wrist pin height?

[@ericyeo2040]

A 107 can upsize to a 128 but it will need a 4.310 piston which will have a thin cylinder wall..

[@maze5178]

Its that hot 90 days straight here in Central Florida.

[@brianshea5349]

Great video excellent information enjoy all your videos Mt Washington fantastic !!!

[@gmayne5663]

There’s very few dealerships now that really have true mechanics ! They’re part pushers and part installers . You should have a conversation about what you want . Take notes on what they suggest and call they manufacture of the parts to see if it will work. Costly mistake on that dealer that they will never refund or admit they screwed up .

[@40indyuk]

2nd time i've heard of this, need the right pistons thats all cylinders are same

[@shermancrum]

The stroke does not change using a big bore kit.

[@joed3539]

What do u think about the s&s bigbore kit for the 114 M8.please

[@michaelclarke9336]

What's the results of cylinder walls being thinner, what issues can this cause? Thanks, great information

[@michaelofiara9732]

Yeah but you dont shovel heat and humidity. Bring it on. Love this heat wave.

[@billyblurton4803]

Rod couldn’t change stroke ?

[@juliusmchristian4748]

Perfect! You did an awesome job with this. Great info. You sound like a pro bike mechanic👍🏼👍🏼

[@gchibber09]

Thats amazing! Been wanting to see you collab with Traveling Tall and Queen Sit!

[@normanmatura6769]

Deck the heads and put a thinner head gasket

[@greggatto1428]

They should of sold him the Harley Davidson 128 kit. Complete bolt on and UNDER WARRANTY!!

[@mikeessary4925]

Happy independence day! Thanks for sharing this info!!

[@claybeck8851]

New Harley owner here. So what can I do to make my 107 faster without compromising

[@johnhaake8988]

I say it all the time.There is a big difference between a parts installer and a engine builder.

[@gerrymiller7401]

Easy way to put it - don't buy S&S big bore. I put the HD 128 kit in '17 Limited with no issues. Installed a Woods cam and now getting 141HP and 151T. Best money I ever spent.