Dyna with a vibration

[stafford]

Well it's not really a vibration, it's not a buzzy kind of vibration.  More like a lope in the engine at mid range rpms. If it matters it's an 03 completely stock engine except for the pipes and maybe the breather. It's been 6 or 8 years since I rode it but it really felt strange with that lope, almost like a galloping horse? Sounds crazy I know but i was hoping someone here might have an idea what's going on with it. I would love to be able to go to him and tell him what yall think.
Thanks Stafford

[Armin]

Check the engine mount and rubber isolator.

Armin.

[sprocket99]

If it's been that long since you haven't ridden the bike, it's time to clean the carb, at the least. Not for any vibration, but for the lope you describe.

[Hossamania]

If it's been that long since you haven't ridden the bike, it's time to clean the carb, at the least. Not for any vibration, but for the lope you describe.

I think he's inferring that the owner rides the bike regularly, but it's been 6 years since the op has ridden it. That's what I got out of it reading it again.

[kd]

Is it carb or EFI?  The "galloping horse" description is fairly vague but I will take that to mean it is "hunting".  More like a regular repeated RPM surge.  That is usually caused by AFR off balance.  It is often caused by the fuel mix being off due to varnish build-up. I have encountered this many times.  Recently I had a open loop tune do this for no known reason. My investigation found the last time the exhaust was installed the tech used OEM exhaust gaskets and crushed them so hard that they intruded alll around into the port flow for an average of 1/8" changing the AFR characteristics.  If in fact the condition you describe is what is known as hunting, it is likely the AFR is being modified by a condition similar to what I describe.

added later:

Is this symptom you are describing caused by engine RPM surging up and down?

[Buglet]

   If its galloping while riding it , it's most likely the tires from sitting.

[stafford]

its nothing like when my front mount on my roadking went bad. it would buzz you half to death. It's not the engine surging, it ran slick as can be he was riding it regularly at the time and the tires werent flat spotted.  it seemed to happen at a certain range in the rpms.  you didn't have to be ringing it out to make it happen. It's a strange thing to me. seriously a little bit of a loping action is not a bad description.   I was  wondering if those internal balancers could have anything to do with it. Thanks for the help guys. Stafford

[Armin]

The are no balancers in a Dyna engine.

Armin.

[stafford]

Well that would surely rule that out.  Could his flywheels have slipped some. He'd been know to ride it pretty hard at times.