HarleyTechTalk

Technical Forums => EVO 1340 => Topic started by: nw69fl on June 26, 2021, 07:22:28 AM

Title: 96 Fatboy sluggish
Post by: nw69fl on June 26, 2021, 07:22:28 AM
When accelerating, the bike seems to struggle, but when I let up on the throttle it smoothes out. Is this a symptom of a slipping clutch or of a too large of a main jet? I mention the main jet because when coasting on compression it backfires and when starting a warm engine it occasionally backfires. Any  thoughts? :scratch:
Title: Re: 96 Fatboy sluggish
Post by: harpwrench on June 26, 2021, 07:36:00 AM
Replace the vacuum hose on the VOES, and make sure the VOES itself is working right
Title: Re: 96 Fatboy sluggish
Post by: JW113 on June 26, 2021, 08:35:46 AM
Yes, possible vacuum leak, but let's start from the beginning and work our way from there.

What jets are in the carb?

Main = ?
Pilot = ?
Needle = ?
Idle screw = turns?

And while we're at it, how about a little more info about the motor?

Cam = ?
Headwork?
Exhaust?
Timing set to = ?

-JW
Title: Re: 96 Fatboy sluggish
Post by: Hossamania on June 26, 2021, 09:02:20 AM
How old are the spark plugs?
Is the chrome cover on the coil touching the plug wires? Are the wires touching anywhere else?
Any work been done to it lately?
Could it be bad gas?
Dirty air filter?
Cracked exhaust? (Just replaced my brother's '95 exhaust, broken at the crossover)

Title: Re: 96 Fatboy sluggish
Post by: nw69fl on June 26, 2021, 09:41:41 AM
Not sure on current jet sizes. Never been apart. I will pull carb and check inlet gasket and clean the carb. Plugs are new. ?
How do I check the function of the VOES? I'll check jet sizes at that time.
Title: Re: 96 Fatboy sluggish
Post by: harpwrench on June 26, 2021, 11:53:54 AM
Quote from: nw69fl on June 26, 2021, 09:41:41 AM
Not sure on current jet sizes. Never been apart. I will pull carb and check inlet gasket and clean the carb. Plugs are new. ?
How do I check the function of the VOES? I'll check jet sizes at that time.
You make sure the hose is good, and see if the timing changes with it connected/disconnected. If it has a ground wire from VOES to the motor mount make sure it's not broken

It's not about the vacuum leak, it's about timing
Title: Re: 96 Fatboy sluggish
Post by: harpwrench on June 26, 2021, 12:37:09 PM
 http://www.wildwestcycle.com/f_voes.html (http://www.wildwestcycle.com/f_voes.html)
Title: Re: 96 Fatboy sluggish
Post by: hogget on July 04, 2021, 01:45:42 AM
not sure if this is relevant, but  i had similar problems with my 88 heritage - see thread '88 flstc sluggish ....' below
fixed now
hth
rory