Known problems
Spring-loaded cam chain tensioners (2000 to 2006 Twin Cam 88B)
high concern2000 to 2006
Rider calls the spring-loaded tensioners on the Twin Cam 88 a widespread flaw. The plastic shoe wears, and debris can score the oil pump and has led to reports of catastrophic engine failure. Rider did not name Softail models, and gave no failure rate. Harley-Davidson sells a hydraulic upgrade kit listed as fitting 2000 to 2006 Softails. Owners on a Softail forum also call the tensioners the main known weak point, though several report high-mileage bikes with no trouble. The original equipment is spring-loaded. Many owners swap to gear drive cams or hydraulic tensioners.
Ask or check: Ask if the tensioners were upgraded (hydraulic tensioners or gear drive cams) and ask for the receipt. If not done, ask when they were last inspected and budget for the work in your offer.
Sources: Rider: Relieving a Tension Headache , Harley-Davidson: hydraulic tensioner upgrade kit (fitment list) , HDForums: owner reports on Fat Boy Twin Cam reliability
Hydraulic tensioner shoe wear on 2007 to 2017 Twin Cams
low concern2007 to 2017
Hot Bike reports the factory moved to hydraulic tensioners by 2007, which eased the problem but did not remove it. Hot Bike's source is a shop that sells related parts. In one owner thread about Twin Cam 96 touring bikes, shoes opened at 50,000 to 100,000 miles were mostly in good shape, while a few owners reported heavy wear. The owners disagreed on how much it matters, and no one found a published factory interval. We found no Softail-specific failure data.
Ask or check: On high-mileage bikes, ask when the cam cover was last opened and what the shoes looked like. Ask for records of any tensioner or gear drive work.
Sources: Hot Bike: Speed's Spotlight (the shop featured sells gear drives and cam parts) , HDForums: owner reports on Twin Cam 96 tensioner wear (touring forum) , J&P Cycles: S&S hydraulic tensioner shoe (fitment list includes Fat Boy 2007 to 2017)
Oil sumping on early Milwaukee-Eight Softails
medium concern2018 to 2019
Harley-Davidson service bulletin M1450 says 2018 to 2019 Softail models with the Milwaukee-Eight engine can experience sumping during long periods at high rpm or under heavy load. Excess oil stays in the crankcase, which can cause loss of power, strong engine braking and potential engine damage. The bulletin gives dealers a diagnostic procedure and lists replacement oil pump parts. It covers Softail models in general and does not name the Fat Boy, so confirm with a dealer using the VIN. We did not read the full repair procedure.
Ask or check: Ask about loss of power or strong engine braking on long high-rpm runs. Ask whether a dealer did work under bulletin M1450 and ask for the records.
Sources: Harley-Davidson service bulletin M1450, on file with NHTSA
What to check on a Softail Fat Boy
- Confirm the engine family from the year and the engine case: 88B, 96B, 103B or Milwaukee-Eight.
- 2000 to 2006: ask for proof of a cam tensioner upgrade. If none, ask when the tensioners were last inspected.
- 2007 to 2017: on high-mileage bikes, ask if the cam cover has been opened and what was found.
- 2018 and later: ask about loss of power on long high-rpm runs and any dealer work under bulletin M1450.
- Check the belt for cracks, missing teeth and rock damage, and ask when it was last replaced.
- Look closely at the chrome and the solid disc wheels for pitting, peeling and curb damage. Both are costly to fix.
- Check the exhaust for heat discoloration, dents and aftermarket pipes. Ask what tune is installed and for the dyno or tuner sheet.
- Look at the rear tire. Fat Boys carry wide tires and wear patterns can show riding style or misalignment.
- Check that the forks are not leaking and the steering is straight, since the fork and front end are heavy.
- Ask for a list of every modification, who did it, and whether the stock parts come with the bike.
Do these on top of the standard walkaround. The free kit has the full list. Want a pro to look it over? Find a local shop.
Safety recalls
Recalls are fixed free by a dealer, but only if someone took the bike in. Ask the seller for proof, or have a dealer check the VIN. You can also check a VIN yourself at nhtsa.gov/recalls.
2025 to 2026 crankcase (pcv) #26V270000
NHTSA lists this for: FLFB. Check the VIN to confirm it applies.
Harley-Davidson Motor Company (Harley-Davidson) is recalling certain 2024-2026 FLTRX, FLHX, 2025-2026 FXBR, FLFB, 2025 FLHXU, 2026 FLTRXL, FLTRT, FLHXL, and FLHLT motorcycles built with an Airbox Baseplate (part number 29000373). The airbox backplate breather port may be blocked, allowing pressure to build up inside the crankcase.
Risk: When the dipstick is removed while the crankcase is pressurized, oil may eject from the fill spout, increasing the risk of injury.
Fix: Dealers will inspect the breather port, and if the port is blocked, repair the blockage, free of charge. Owner notification letters were mailed May 14, 2026. Owners may contact Harley-Davidson customer service at 1-800-258-2464. Vehicle Identification Numbers (VINs) involved in this recall became searchable on NHTSA.gov April 16, 2025. Harley-Davidson's number for this recall is 0193.
2017 clutch assembly #18V734000
NHTSA lists this for: FLSTFBS. Check the VIN to confirm it applies.
Harley-Davidson Motor Company (Harley-Davidson) is recalling certain 2017-2018 Police Road King (FLHP), Road King (FLHR), Road King Special (FLHRXS), Electra Glide Ultra Classic (FLHTCU), Ultra Limited (FLHTK), Ultra Limited Low (FLHTKL), Ultra Limited Shrine (FLHTK SHRINE), Police Electra Glide (FLHTP), Street Glide (FLHX), Street Glide Special (FLHXS), Road Glide Ultra (FLTRU), Road Glide (FLTRX), Road Glide Special (FLTRXS), Freewheeler (FLRT), Tri Glide Ultra (FLHTCUTG), CVO Limited (FLHTKSE) and CVO Street Glide (FLHXSE) motorcycles, 2017 Softail Slim S (FLSS), Fat Boy S (FLSTFBS) and CVO Pro Street Breakout (FXSE) motorcycles, 2018 115th Anniversary Ultra Limited (FLHTK ANV), 115th Anniversary Street Glide (FLHX ANV), 115th Anniversary Street Glide Special (FLHXS ANX), 115th Anniversary Tri Glide Ultra (FLHTCUTG ANV), 115th Anniversary CVO Limited (FLHTKSE ANV) and CVO Road Glide (FLTRXSE) motorcycles. The secondary clutch actuator cylinder may leak fluid internally and the clutch master cylinder may lose the ability to generate enough lift to disengage the clutch.
Risk: If the clutch cannot be disengaged it can result in a loss of control, increasing the risk of a crash.
Fix: Harley-Davidson will notify owners, and dealers will install a new secondary clutch actuator piston assembly, free of charge. The recall began November 5, 2018. Owners may contact Harley-Davidson customer service at 1-800-258-2464. Harley-Davidson's number for this recall is 0173.
2016 clutch assembly #16V471000
NHTSA lists this for: FLSTFBS. Check the VIN to confirm it applies.
Harley-Davidson Motor Company (Harley-Davidson) is recalling certain model year 2016 Electric Glide Ultra Classic (FLHTCU), Electra Glide Ultra Classic Low (FLHTCUL), Ultra Limited Low (FLHTKL), Ultra Limited (FLHTK), CVO Street Glide (FLHXSE), Street Glide (FLHX), Street Glide Special (FLHXS), Road Glide Special (FLTRXS), Road Glide (FLTRX), Police Electra Glide (FLHTP), Road Glide Ultra (FLTRU), Fat Boy S (FLSTFBS), Softail Slim S (FLSS), and CVO Softail Pro Street Breakout (FXSE) motorcycles. In the affected motorcycles, the clutch master cylinder may lose the ability to generate enough lift to disengage the clutch, especially if the motorcycle has been parked for an extended period of time.
Risk: When the engine is running and the motorcycle is in gear, if the clutch cannot be fully disengaged, the motorcycle may move unexpectedly, increasing the risk of a crash.
Fix: Harley-Davidson will notify owners, and dealers will inspect the clutch master cylinder for the presence of gas in the fluid, if so, the dealer will flush the clutch system and rebuild the clutch master cylinder, free of charge. The recall began July 19, 2016. Owners may contact Harley-Davidson customer service at 1-800-258-2464. Harley-Davidson's number for this recall is 0169.
2007 cables #07V173000
NHTSA lists this for: FLSTF. Check the VIN to confirm it applies.
CERTAIN MOTORCYCLES WERE BUILT WITH A CONDITION THAT PERMITS THE POSITIVE BATTERY CABLE TO CONTACT A WELD BEAD ON THE OIL TANK. THIS MAY CAUSE THE WELD BEAD TO ABRADE THROUGH THE INSULATION ON THE CABLE AND CAUSE AN ELECTRICAL SHORT FROM THE BATTERY THROUGH THE OIL TANK AND OIL LINES.
Risk: THIS COULD LEAD TO AN OIL LEAK AND/OR POSSIBLE FIRE, WHICH COULD RESULT IN INJURY OR DEATH TO THE RIDER.
Fix: DEALERS WILL INSTALL A BATTERY CADDY THAT WILL PROTECT THE CABLE AND ENSURE PROPER CABLE ROUTING. THIS RECALL BEGAN ON MAY 4, 2007. OWNERS MAY CONTACT HARLEY-DAVIDSON AT 1-414-342-4080.
2002 to 2005 labels #05V151000
NHTSA lists this for: FLSTF, FLSTFI. Check the VIN to confirm it applies.
CERTAIN SOFTAIL MOTORCYCLES FAIL TO COMPLY WITH THE REQUIREMENTS OF PART 567, 'CERTIFICATION.' THE VIN/CERTIFICATION LABEL CONTAINS INCORRECT TIRE SIZE AND INFLATION PRESSURES FOR THE FRONT WHEEL. THE LABEL STATES THE TIRE SIZE IS MT90B21 AND THE INFLATION PRESSURE AS 30 PSI, WHEREAS THE CORRECT TIRE SIZE IS MT90B16, AND THE CORRECT INFLATION PRESSURE IS 36 PSI.
Risk: THE CERTIFICATION LABEL IS INCORRECT GIVING IMPROPER INFORMATION.
Fix: HARLEY- DAVIDSON WILL MAIL INSTRUCTIONS ALONG WITH CORRECTED FEDERAL CERTIFICATION LABEL. IF AN OWNER SO DESIRES, A DEALER CAN INSTALL THE LABEL FOR THEM. THE RECALL BEGAN ON JUNE 6, 2005. OWNERS MAY CONTACT HARLEY-DAVIDSON AT 1-414-343-4056.
1999 tank assembly #99V200000
NHTSA lists this for: FLSTF. Check the VIN to confirm it applies.
VEHICLE DESCRIPTION: MOTORCYCLES. THESE MOTORCYCLES WERE BUILT WITH A FUEL TANK VENT FITTING THAT COULD BE PLUGGED ALLOWING THE CARBURETOR TO OVERFLOW FUEL.
Risk: THIS COULD RESULT IN A FIRE.
Fix: DEALERS WILL INSPECT THE FUEL TANK VENT FITTING AND, IF PLUGGED, WILL CORRECT THIS CONDITION.
1990 to 1992 relay #92V180000
NHTSA lists this for: FLSTF. Check the VIN to confirm it applies.
THE STARTER RELAY MAY SHORT CIRCUIT WHEN THE VEHICLE IS PARKED.
Risk: THE SHORT CIRCUIT IN THE STARTER RELAY MAY DEVELOP ENOUGHHEAT TO CAUSE A FIRE IN THE RELAY, OTHER PARTS OF THE MOTORCYCLE, AND OTHERITEMS IN THE SURROUNDING AREA.
Fix: REPLACE THE STARTER RELAY.
NHTSA data fetched 2026-11-06.
Is it a good first bike?
Comfortable and easy to ride once moving, but it is a heavy bike with wide tires. Sit on one and push it around first. Consider a handling course.
Generations
Evolution
1990 to 1999
Evolution engine. The Twin Cam cam chain notes below do not apply to these bikes.
Twin Cam 88B
2000 to 2006
Twin Cam 88B engine, a balanced version made for the rubber-mounted Softail. Spring-loaded cam chain tensioners. Fuel injection arrived on Softails in 2001, according to owner reports.
Twin Cam 96B
2007 to 2011
Twin Cam 96 engine with a 6-speed transmission. Hydraulic cam chain tensioners. The Fat Boy Lo (FLSTFB) was added in 2010.
Twin Cam 103B
2012 to 2017
Twin Cam 103 replaced the 96 on Softails. Last years of the old Softail frame with twin rear shocks. The Fat Boy S (FLSTFBS) appears at the end of this run.
Milwaukee-Eight on the new Softail frame
2018 to present
New steel frame with the engine solid-mounted, and a single shock under the seat. Milwaukee-Eight 107 (FLFB) or 114 (FLFBS). A 117 engine is reported for 2025. The 2018 Softail line replaced the Dyna.