Hello,

I have a Dyna 2006; 16000 miles with Andrews 26 and a recent 98 ci bore, which I these days ride around fine tuning with the PV.

I noticed a vibration at low rpm - but ONLY when engine is hot and been so for a longer while. It can vibrate at standstill at decel after giving a little throttle. When it is on it’s way back to idle it vibrates.

My front motor-mount is Predator, I should mention, and it makes the bike a bit stiff around 2.000-2.500 rpm. Otherwise it is good.

On the primary side there are some sounds going on, (like marbles? yes), although not alarming. (I have replaced IPB and installed Hayden 2 years ago.) I opened it this summer checking the rotor, compensator nut, but could not find anything obviously wrong. (But not sure about the spring pack.)

My questions are:

Could it be excessive runout? (It was 0.0021 plus the gap of 0.0007 before cam and big bore 2 years ago.)

Or could it be the stock compensator? It can make sounds upon startup when engine is warm. As I mentioned above I cannot tell if the spring pack was faulty in some way. But I noticed there was an obvious gap above it. Could it have collapsed a bit?

It would be great if someone would ease my mind by writing here it is the compensator, as I have planned to replace it anyway

But all serious suggestions are appreciated.

Thanks in advance.

Oak Mountain Rider

P. S. 1 Bike was tuned this summer by a tuner, receiving new VE-tables. So now I am in the process of fine-adjusting AFR and spark advance. But different AFR and timing does not seem to be related to the vibration issue. Only heat does, when the whole engine is hot after a long ride.

P. S. 2
Bike runs fine, even when ET is high (270 F). But after been in prolonged heat, it feels a bit strange and it vibrates more.

 

IIRC, 2006 Dynas had inner primary bearing issues. While you’re checking other issues of your concern, be sure to check that.

 

Thanks for your answer. I think I will check the inner primary bearing this winter.

 

Chasing the cause of vibration, and harsh running at the lower rpm range, I have after two sessions of autotunes of the local tuners tune, (with additional smoothing of the VE:s by right clicking with the mouse), began to see light in the tunnel. An amazing difference has occurred by pulling timing. I want to thank marqodarc and Max Headflow for good advice. Feels like my bike’s engine has entered a new universe. See the last part of the thread linked below:

https://www.hdforums.com/forum/ignit...in-a-tune.html