XB9S Primary Chain Adjustment (any recommendations for...)

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Danthehitman

Well-known member
Joined
Feb 18, 2020
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109
Location
Milwaukee and Illinois
Hey everyone!

So, I'm thinking about digging back into the Primary Chain adjustment. It didn't look like it was noticeably out of spec so I didn't really examine it super closely but, as some of you may already know, I'm trying to improve that 1st-to-2nd shift "crunch". From what I can tell this adjustment would be a lot easier with the Primary Case off the bike so I'm considering pulling it unless anyone has advice that might save me the hassle?

I know finding the "tight spot" of the chain is critical and having the primary case on it's not possible to get an overall view of the chain. I was thinking maybe I'd put a paint-marker dot the edge of the chain, perhaps? Or, does anyone know if there's a clever way to correlate the wheel rotation to primary chain rotation?

Thanks and hope you're all doing well!
 
Hey Dan, you can't adjust the primary chain with the cover off. Check out the exploded view in the service manual, the adjustment screw and foot are in the primary cover. The factory procedure is good and can be followed without a problem but FWIW, I go old skool with the primary adjustment. I have been a professional technician my whole entire life, and this has worked for me 100's of times on all sorts of V-twins.

I feel it is more precise, because it addresses any tight link issues:eagerness:

With the engine idling at operating temp, Hold the adjuster, Loosen the locknut 1/2 to 3/4 of a turn, then loosen the adjuster (unscrew, while holding the previously loosened locknut from rotating), until it gets louder (rattly sounding), then tighten slowly (still holding the locknut still). As you tighten it, the chain should get quiet and then loud again, but more of a whirring noise this time. When it makes that louder 'whirring' noise it's too tight so back it off until it gets quiet again and go 1/2 turn more, then hold that adjuster and tighten the locknut to spec.

At no point should you have to put significant pressure on that adjuster, more than the locknut nylon friction.

The noise should be very obvious but in case you are unsure, mark the side of the adjuster bolt, so you can put it back where you found it.

The whole locknut procedure is to keep it close to the primary cover, but not interfere with the adjuster rotating. It's not terrible to just unscrew the lock nut a few turns out of the way, then adjust it, but remember to hold the adjuster while final tightening the lock nut.

Important to note:
It is much better to have a primary chain too LOOSE than even a little too tight.

I hope I described that clearly? Wouldn't want someone to go all mushroom cloud rant-y-pants:black_eyed: LOL
 
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Your primary chain would have to be dramatically way too loose to affect the 1-2 shift.

Before you do anything, take the 2 bolts out of the inspection cover and see if the adjustment is remotely close now. 3/8"- 1/2" is very close depending on temp.

Is your clutch releasing fully? Does the bike want to creep forward in 1st at a stop? Hard to find neutral?

Can you describe the 'crunchy' shift better? These are clunky already, so a bang into 2nd is normal. If it feels like its skipping, chattering, or grinding, then I'm afraid you may be in for a gear set. They can act that way for a LONG time before they cause you issues though. Pretty stout transmissions in a Buell.
 
Hey Cooter, thanks for the reply. Ya, the Cover holds the adjustment screws, silly me!

Your description sounds good and I like the process better than the factory process. I'll give it a shot hopefully later in the week and report back. Much appreciated.
 
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