It doesn't have anything to do with it being an Evo. The Twin Cams that aren't balanced shake just as much, as do the Shovels, Pans, and Knuckleheads. It's the nature of a 45 degree, single crankpin V Twin engine. Balance Masters makes balancers for the clutch and compensator that are supposed to make a huge difference in the vibration. They use mercury as part of the weight in the balancers, so the liquid can self-adjust to different levels of vibration. I've got to say their website is horrible, but I've read tests of their products that were very favorable.

 

Good point mp. All my previous rides have been 88B's or a 1200C. I love the shake my 1200 has and it smooths out as the rpm's build. Thanks for the balance master tip. I'll check it out.

 

Check out the engine mounts, make sure the exhaust is not touching the frame or anything else as this will cause a vibration. Check the adjustment of the primary chain and final drive belt. Check out the alignment of the drive train. If all this checks out then do a compression and leak down test. If all this checks out then you might want to try an active engine balancer like Fisher etc. Hope this helps. Well I gotta go now, we are going to see Willie Nelson tonight.

 

Checking primary chain is always good - most don't do it even at a service, though you generally won't get vibration form there, just noise. Rear belt adjustment will make major differences in vibrations on some bikes. Some need to run a little loose and some a little snug. And many bikes will check loose when cold and get super tight after run a short distance. Go over the exhaust really good, make sure there's nothing touching where it shouldn't and that all attachment points are tight. Even, and maybe especially, on a rubber mount, any changes in the exhaust can have dramatic results in vibration. I really don't understand why, but know it to be true.

Also true is the fact these engines will vibrate at some point in the rpm range - fact of life. And "balancing" will change that. But it will only adjust the vibration to a different rpm range - believe me!

One thing that's not been suggested - check your VOES for proper operation. If it's lost ground or inoperative, that will definitely make it vibrate until you get into higher rpms (3500+) Yea, it'll start and run fine, and sound really good with loud pipes too, but these EVOs don't like it when the timing is way low. Another fact I've learned the hard way.....

 

It's not because it is an Evo,it is because it is frame mounted and a big twin.goes with the territory.Balancing will not help, change the cruise rpm with pulleys which will slow the motor down.If you are a hot rodder move the rpm up it to will help at cruise speed.Try cruising at different speeds you will see for yourself how it works.

 

Front motor mount.... If vibration persist then take a look at the primary. I had my final drive pulley nut back all the way off and had noticed very bad vibration before this occurred..


Hope that helps man.

Ride Safe Ride Free.

 

That's exactly what I did. The problem was I waited two years before I did that, for some strange f*&cking reason.

I also have the rubber mounted dog-bones, and of course the smaller rear pulley, single fired ignition, rubber isolated grips, and a plushy seat

I think I have the smoothest FXSTS on the planet.

 

I have a 96 FLSTC that is stock except for the Mustang seat and a Dyna 2000 ignition pack. I found at around 2000 to 2500 RPM the vibrations a very comfortable, or at least not as much of an issue as at higher or lower RPMs.

 

I run those Terry/Fisher balancer off the front engine shaft (inside the front belt pulley sprocket ) These are S&S 96 CI motors and I did see an improvement on the vibrations or maybe I just had more beer before I took off ! I don't even know if those dampers are available anymore They were big $'s

 

"Harley-Davidson: Making Ladies happy since 1903...."