103 to 107 worth it?
Elite HDF Member
Joined: Sep 2012
Posts: 3,791
Likes: 57
From: N Texas
If you got the $$ for more power, then why not? The FM 107" kit is a nice upgrade, maybe the extra 4 cu in is not tremendous but it does have value and putting in forged pistons vs the cast stock ones is certainly worth something(will help handle the higher compression you will need for nice cams). Personally I would choose headwork over the kit, and if you are already paying someone to pull the heads off, it makes a lot of sense to get the FM B heads put on while your at it. Definately would toss the slip-ons for a nice 2 into 1, with all this you are going to have a very fun bike!
Well, I had a great running stage II 103 that I built out to 107. I'd do it again, in a heartbeat, but I also put ported heads on at the same time.
If your choices (constrained by budget) are:
A) keep the 103, add cams and spend the money on ported heads
B) go to 107 with cams but keep stock heads
I'd take A every time. You will be bumping your compression up to whatever you need, and you'll be matching your heads to your cams. Send your heads to a good shop, like Baisley, Dewey's, B C Gerolamy, or Headquarters (to name a few) and you'll match or better the power gains from the "B" choice.
If your choices (constrained by budget) are:
A) keep the 103, add cams and spend the money on ported heads
B) go to 107 with cams but keep stock heads
I'd take A every time. You will be bumping your compression up to whatever you need, and you'll be matching your heads to your cams. Send your heads to a good shop, like Baisley, Dewey's, B C Gerolamy, or Headquarters (to name a few) and you'll match or better the power gains from the "B" choice.
Ultimate HDF Member
Joined: Mar 2012
Posts: 6,129
Likes: 143
From: Santa Cruz
If it is a '13 street glide I'd do a stage 4 kit and keep the warranty. If ya don't care about the warranty, putting some 10-1 pistons and 57h cams in your 103 would be good bang for the buck. Should brake 100hp and 110 tq pretty easy with proper tune and pipe. All ya really get with the FM kit is higher compression for bigger cams. The 4 cubes mean little but it's not a bad deal for a bolt in kit.
Tourer
Joined: May 2007
Posts: 337
Likes: 56
From: Joshua Tree, CA
here's a thought.......
i just bought a '13 streetglide 103".
I also own an 07 electragide Police 103"
the '13 is a dog compared to the 07.
i checked the gearing ratios in the transmission and pulleys and found the 13 is geared higher than the 07. it makes it fine for cruising, but for acceleration it suffers. more fun to ride the 07.
seems a pulley and belt change might put more zip into the 13 if possible.
i just bought a '13 streetglide 103".
I also own an 07 electragide Police 103"
the '13 is a dog compared to the 07.
i checked the gearing ratios in the transmission and pulleys and found the 13 is geared higher than the 07. it makes it fine for cruising, but for acceleration it suffers. more fun to ride the 07.
seems a pulley and belt change might put more zip into the 13 if possible.
Road Warrior
Joined: Apr 2010
Posts: 1,648
Likes: 37
From: Monroe, Louisiana
here's a thought.......
i just bought a '13 streetglide 103".
I also own an 07 electragide Police 103"
the '13 is a dog compared to the 07.
i checked the gearing ratios in the transmission and pulleys and found the 13 is geared higher than the 07. it makes it fine for cruising, but for acceleration it suffers. more fun to ride the 07.
seems a pulley and belt change might put more zip into the 13 if possible.
i just bought a '13 streetglide 103".
I also own an 07 electragide Police 103"
the '13 is a dog compared to the 07.
i checked the gearing ratios in the transmission and pulleys and found the 13 is geared higher than the 07. it makes it fine for cruising, but for acceleration it suffers. more fun to ride the 07.
seems a pulley and belt change might put more zip into the 13 if possible.
Stage II
Joined: Jul 2013
Posts: 2
Likes: 0
From: Houston
I had the 103 kit from Harley and cams upgrade on my 2008 Night Train. Do not waste your money. My bike is fine for me and sounds really good but you will not notice a power difference I assure you and the gas mileage will flop. Don't get me wrong I like what I have done and only regret putting the screaming eagle tuner on with it. I have change to the Thunder Max much better performance and fuel economy now.
Cruiser
Joined: Dec 2012
Posts: 144
Likes: 0
From: Arizona
http://www.fuelmotousa.com/site/107-inch-big-bore.html
I'm about to pull the trigger on this kit and have my Harley mechanic install it he wants about a grand for the complete job....
BEFORE I do anything, after the kit is installed what needs to be done to have the bike rideable and reliable like it is now?
A tune? Intake? I have Rinehart slip ons....if that helps LOL
I want a little more pep and some power the 103 is OK but for this price it seems to be worth the gains?
I'm about to pull the trigger on this kit and have my Harley mechanic install it he wants about a grand for the complete job....
BEFORE I do anything, after the kit is installed what needs to be done to have the bike rideable and reliable like it is now?
A tune? Intake? I have Rinehart slip ons....if that helps LOL
I want a little more pep and some power the 103 is OK but for this price it seems to be worth the gains?
You will spend all that money and within no time want more again. It never ends. You will also lose some mpg's and don't let anyone tell you otherwise. EVERY bike I did heads on increased engine temps and ate several mpg's. Every one! Cams, not so much.
I say save the money and just enjoy the bike for a while.
Tourer
Joined: May 2012
Posts: 352
Likes: 0
From: Egg Harbor Township, N.J.
I wouldn't do it. I don't think you'll be happy with the results for the price and as others have stated, there goes your powertrain warranty. Not worth it. If you need to go fast buy a sport bike.
HD Forum Stories
The Best of Harley-Davidson for Lifelong Riders
7 Surprising Harley-Davidson Products that Are Not Motorcycles
Verdad Gallardo
8 Best Harley-Davidson Motorcycles Ever
Pouria Savadkouei
10 Worst Harley-Davidson Motorcycles Ever
Pouria Savadkouei
Killer Custom's Jail Break Is The Breakout That Refused to Blend In
Verdad Gallardo
Crazy Bunderbike Build Looks Amazing, But Is It Impossible to Ride?
Verdad Gallardo
Harley-Davidson Reveals Super Cool Cafe Racer Concept
Verdad Gallardo
Engraved Rebellion: Inside Bundnerbike's Glam Rock II
Verdad Gallardo
10 Motorcycles You Should Never Buy
Joe Kucinski
10 Things Harley-Davidson Needs to Fix in 2026
Verdad Gallardo
Road Master
Joined: Apr 2012
Posts: 858
Likes: 20
From: USA
NOPE, NOPE and finally no! Why not do 110 piston, bore your heads out to fit the 110 piston, get new cams and be done? 103 to 107 isn't worth the investmen, you can do a good job w a good performance machine shop that deals w Twin engines. I'm sure that the board sponsors don't want to hear from members doing their homework and saving money, but you can do a lot if you do the homework.
Go 110 kit be done... Talk to a good INDY shop that can do your work, that isn't too focused on advertisemnet but is more concern about word of mouth and happy customers and real performance work. Personally I wouldn't do 107 because its not worth it, now a 110 is totally different!
Go 110 kit be done... Talk to a good INDY shop that can do your work, that isn't too focused on advertisemnet but is more concern about word of mouth and happy customers and real performance work. Personally I wouldn't do 107 because its not worth it, now a 110 is totally different!
Last edited by chgofirefighter; Jul 9, 2013 at 06:18 AM.
Stellar HDF Member
Joined: Oct 2007
Posts: 2,806
Likes: 1,754
From: New Bern NC
I did a Head Quarters 103' with heads, cams, and exhaust at 22,000 miles. It made 108/110. It has over 80,000 on it now. That includes two up touring as well as hauling a camping trailer with my youngest on the weekends.