.

Glad I thought to finally try to capture it on video at least I won't get anymore "it's suppose to shake" comments. It ain't suppose to shake like this. I'm hoping Spanners comes up with a good idea, I'm going to google and try to figure out how to test the ignition system with more than just ohms is like to test it at that rpm range somehow.

 

Just wondering if you ever checked tension on the drive belt? Outside of that, I would be suspect of the flywheels being off true, as others have said.

 

I thought EVO's had balance shafts? Sounds like the flywheel has spun, or there's a problem with the crank.

 

. Yup checked it. The only reason I think it's not the crank or flywheel is that it doesn't get worse with rpms and it's not gradual, it's calm then hits the rough patch and shakes like hell then goes smooth. I just don't know what else to check or what to mess with on the electrical side. I am getting sick of spending hours working on it at night and getting zero results.

 

Only Soft tail twin cams have those.

 

I have said it before but I will emphasise it again here....crank balance does not give worse vibes with higher revs, it gives a vibration at a certain (and quite small) rev range.....this is a behaviour of harmonics.

My 1987 Sporty did it at 3200RPM which was my preferred cruising speed and was smooth either side of that.

Triumph altered the balance factor on the late unit 650s to get the tingly vibes out of the cruising range.

You have done everything you can (assuming you have checked for tight spots in your primary chain) and got nowhere and this is because the problem is most likely mechanical.

Harmonics exist everywhere there is a rotating mass that isn't in perfect balance....even a brand new jet engine will have a harmonic vibration patch somewhere in its rev range.

I am not saying that your bike is behaving as normal but I do think the issue is caused by a rotating component that is not in perfect balance.

You can try the handlebar weights that help to damp out vibes for early Sporty and Shovel riders, if that makes a difference (try wrapping some lead pipe round the ends of the bars) then you can bet its internal and rotating and can only be fixed by a crank true-up or rebuild and if you can live with the vibes just leave it be until the winter.

Or fly me out and I will fix it

 

Spanners, I triple checked the primary chain for tight spots when I put it back together this last time. I did try the lead trick, rolled up lead sheets, about 5 inches long as far as they would go into bars, made no difference. They were heavy rolled up thick. I guess I'll throw in the towel. Thank guys for the suggestions. If anyone wants to buy it throw me an offer! I'll be riding it daily until then

 

We've already covered that. None of us on here except you have experienced this thing. By the definition of the internet, some of us are an ocean away. As we have already suggested previously find yourself someone close by, an indy if necessary, to demonstrate the problem to. I for one wouldn't throw in the towel!

 

Show a vid of the motor as you take it through that rpm range.

 

. Motor shakes at idle moves a lot like normal, then in that range the engine isn't moving it's holding pretty steady, you wouldn't be able to see it moving. It's not shaking and moving like at idle at all. I'll still try to take one though