Just picked up an 08 Fatboy with 40k on it.

Is there anything in particular I should check out? I did a compression test and both cylinders were around 170. Seems to run great other than the crappy exhaust causes popping. So I hate that.

Just had a lube job, rear belt, new neck bearings, new tires done in July.

Only issue so far is it needs a new starter clutch so if there's anything particular to check I'd like to do it while I have the primary cover off.

16" apes, look pretty crazy but I'm surprised how comfy they are so far. May go to 14s though. Def need new poly riser bushings.

 

While some exhausts are more prone to decel popping than others, it can most times be tuned away, or at least greatly reduced.


The 2008 bikes had the "updated" compensator (updated '06 for Dynas, '07 for all other models). They also had the problematic version of the auto primary chain tensioner introduced at the same time.

The "updated" compensator was problematic until the latest, best version introduced in 2014. You could in fact have a bad starter clutch, but if the symptoms are "banging" on start-up and/or shut-down, you MAY have a bad compensator. If left unaddressed, it can cause damage to the starter clutch...

You can get the newest, best version of the comp for your bike, but it will require you to also switch out to the newer rotor design, separate from the comp on the older "updated" versions. The newer rotor will be part of the comp kit for your bike. But you will need to remove the inner primary case, to change out the rotor. Then you will need to add (epoxy) a scoop into your old outer primary cover to address oil into the new comp bolt.

https://www.harley-davidson.com/us/e...tor/p/40100061


The problematic version of the auto primary chain tensioner is either part #39929-06 or #39929-06A. They would cause the primary chain to ratchet up too tight. The tight primary chain has reportedly caused issues with the trans shaft inner primary bearing.

In 2010, they introduced an updated version of the auto primary chain tensioner #39929-06B. It was a better design, and much less problematic than its predecessors. I used one on a bagger with 135HP/151TQ with no issues. They updated that auto tensioner again, around 2020ish, to the #39929-06C version.

If your primary chain is too tight upon inspection, and you have the earlier problematic versions of the tensioner, you can swap out the older versions (-06 or -06A) with the "C" version and most likely be problem free with the new version...

Good luck with your inspection and repair.... Report back what you find and how you fixed it..

 

I'll def check out that tensioner and probably go ahead and order it.

Im pretty confident its the starter clutch, it doesn't start to act up until the bike gets warm and only on startup. Seems pretty in line with other things I've read/watched.

 

Well nevermind I guess, think I'm trading for a 05 Dyna Low Rider this weekend and so we'll see how it goes lol.