Depending on which kit I look at, most complete kits (ported heads, big valves, barrels, pistons, pushrods, cam, and EFI tune) hp goes north of 100hp.

Is this number okay for the bottom end?

Because, my logic is; If hp bumps to the point of a bottom end upgrade, I'll stroke it as well as big-bore it.

What say the collective?

My bike will be 20 years old next year and I'm looking to get it refreshed. Bike is bone stock except the OEM exhaust was punched out.

2003 FSXSTDi Deuce (EFI), original owner.

 

The 03s had an issue when bumping the power past 100 /100 where the left side main bearing would give out.. I seem to remember that HD changed the torque procedure for sprocket shaft helped but HD also upgraded the left side bearing. I would go into the the bottom end and have it replaced. In that case you can stroke it if desired.

 

Thanks man, 'preciate that.

These projects can get a bit out of hand... rabbit holes and such.

"The motors out, might as well take care of that bottom end".

leads to

"Might as well put that S&S stroker kit on"

leads to

"Might as well put that S&S cam plate and upgrades on while I'm in there"

leads to

"Might as well upgrade the clutch"

leads to

"Might as well upgrade the transmission"

How come I'm thinking I'm about to go waay down a hole....

 

How many miles on that 20yr old bottom end. How far north of 100/100 do you want to go? 03 was a decent crank with weak left side bearing setup. Bearing upgrade available from HD.
But if looking for serious hp increase, S&S 4.375 or 4.625 stroke crankshaft assemblies, maybe left side Timken conversion (debated) is where to start. At least that's what I would do

Your transmission is pretty much bullet proof. Clutch not so much

 

Just turned over 11K (I have multiple bikes, so the annual mileage is spread out).

Two ways to go IMO for me:

-Big bore, port/flow the heads, gear driven cams, good flowing air cleaner, larger headers into a baffled muffler, EFI tune. Goal would be under 100/100.

-103 big bore/stroker kit (w/ better bearings throughout), new heads (bigger valves, ported/flowed), gear driven cams, beefed up 5sp transmission and upgraded clutch. IOW a quality 103" build with tranny/clutch upgrades to match performance. Goal would be over 100/100 but not insane, and the motor tuned for real-world usable power not peak hp/tq on a Dyno.

Reliability and drivability are the top priorities.

I'm a noob for HD engine builds, but was an aircraft mechanic for ten years. Basic shop stuff but no lathe or welding equipment or skills. Headwork would be sent out.

 

Ok, 11k is very low mileage. Check crankshaft run-out. If less than .003 tir, keep stock crank, replace left and right side bearings with new HD "upgrade" bearings. The right gear drive cams, ported heads, bored cylinders/ pistons, ect. ect... some compression bump, 100+/100+ reliability should not be a problem. Talk to your head porter.. Just got to match components to work well together. Either that or go $BIG$

Your transmission is fine
except swap out mainshaft bearing race for S&S race "inside primary" while you are at it

 

Great minds think alike? :-)

Kinda what my original plan was. Then the thought of opening the case for bearings led to... hmm, a stroked crank would be good, led to all sorts of upgrades. Not really interested in spending north of $6k on a 20 year old Deuce!

With a low crank runout, I'll be putting in gear driven cams regardless. Big bore, flowed heads (maybe bigger valves?), gear driven performance cams, crank bearings, air cleaner, headers, call it good. I can do all that myself (send heads out or replace).

 

The best part of this thread is helping me put a good plan together. I appreciate it.

 

I was in the same situation as you but with a LOT more miles. 120K on 04 FXST. Same bike as yours just trim. I am in the process of looking up from the bottom of the rabbit hole!lol Once I got to the point of splitting the cases I figured go for it. Darkhorse 4.374 stroker, Timkin converg, bottom end blueprint and assembled by them. My old S.E Preformance heads completely reworked Hillside, full bore to 107, S&S oil pump/cam plate, new .570 gear, 45 Mikuni, S.E intake worked, oil cooler, S.E starter, S.E variable pressure clutch....you get the idea. As long as the cases stay together you can keep cost manageable in my thinking. Once you split the cases.....well you done waded in to deep!🤣 Now alot of my cost was replacing old and worn items. My oil pump/plate/starter should be a none issue with you. As stated except for seals at your bikes age transmission should be fine. If you go that deep I would change all the seals as well as the before mentioned 5th gear race to the S&S. My stock one went for a walk some years ago. Good luck

 

That sounds like a real runner!

I really love my Deuce. The Deuce handles better than any Softail should of that under-shock era.

Even if an owner "goes down the rabbit hole" its cheaper than a new bike!

H-D fit and finish really shows after 20 years, my bike still looks fantastic and the Deuce styling has aged really well.

I participated in a H-D ride event, and rode the 2022 bikes Low Rider S (117 engine) , Fat Bob 114, Road King Special, Pan American, CVO Road Glide. They were all great! Except the price. Boy do they cost a lot of money.

What I discovered: More power is awesome. The Fat Bob's engine rev'd pretty freely-I liked that-it had good torque down low, and still had oomph a little higher in the revs. The suspension on all of them were far better than my '03 Deuce, the brakes on all the new bikes were light years better than my Deuce's single brake.

I'd like to capitalize on the short stroke of the TC88, so I won't put a stroker crank in... I really like the OEM look, and I like sleeper bikes... so...

Current Winter Plan:
Crack cases and put in upgraded bearings.
Bore my cylinders to 98"
New 98" pistons (flat top, keep under 10:1 for pump gas)
flow and big valve my heads with springs and rockers, or buy ready-made heads (leaning on my heads to keep OEM look)
cams for mid range to upper range. Will get one of the cam chest w/ cams kits.
Upgrade intake
Headers and baffled pipe (I know, I know.. Ha ha)
Dyno tune
Baker OD6 Builders Kit
Clutch upgrades
Fork internals
Upgraded shocks
Upgrade brakes as much as I can for that single disk.
Wheel bearings
Steering head inspection
Swingarm bearing inspection
Install all new OEM tins (I bought new take-off OEM tins back in '03-tank fenders-off an owner whom installed custom tins on his Deuce, they are zero mile tins and perfect)
While tin is off, inspect everything and address items as needed and a thorough under-tin cleaning/detail.
Paint correct new tin (they've been wrapped in boxes for 20 years)
Blackout all chrome
LED headlamp/signals

Goal is a free rev'ing 98" engine built for reliability, upgrade the chassis as much as possible and blacked out components for an updated look. I'll keep the OEM silver/black two tone paint. That two tone paint with blacked out chrome and the 100th Aniv wings will be fire!

That's a big plan! I paid $18,500 new. I don't mind putting $8-9K into a bike that may or may not be worth that much as I'm the original owner and I don't plan on ever selling this bike. My son can do what he wants with it after I'm in the ground LoL