Hey everyone, I'm getting ready to do a winter engine rebuild on my 98 lowrider and was thinking of sending my lower end off to Revolution Performance to get the crankshaft trued and balanced. I haven't called them yet, I wanted to see if anyone here has used them for this service. My engine has almost 40,000 miles on it and it's burning a little oil in the rear cylinder, still runs good though.
Also thinking of the 85 c.i. cylinders, headwork and a new cam. I was hoping that their true and balancing service would cure my vibration problems.
They seem to be reasonable in price and read good things about them. Trying to keep it in a 2500 dollar budget, doing most of the wrenching myself. I haven't found anything about Darkhorse doing evo cranks, they might be out of my budget anyway. I'm looking forward to all your thoughts and advice on this as it's my first Harley engine rebuild, can't wait to get started !!! Thanks a million guys, any help or tips would be appreciated.

 

What makes you think something is wrong with the crank????
Have your checked your motor mounts for the source of your vibration?

 

Thanks for your responce. I have the Predator in the front and a new stock one in the rear. The upper link is tight and I've been through the alignment procedure more times than I care to remember. I've even used angle gauges. My tires are good, in fact on the highway it's dead smooth and tracks straight. Done the loosening and tightening of the motor mount bolts and the exhaust system and t's still there. Happens in the 2000-2500 rm range then smoothes out.

 

PM what's his name.he is located in western Massachusetts. This is his listing. Sucks I can't remember his name
Http://westernmass.craigslist.org/mcy/5358157201.html

 

Is that KP's bike?

 

If your gonna pull the crank anyway I suggest you go with a stroker crank from S&S.

Just a thought.

 

Yes that sounds right. 1998 Dyna with an odd vibration. He really documented his chasing it down. Probably really easy to find the thread for the op if he searched the site.

 

Thanks again for your replies. I've read many posts on dyna vibration, both evo and twin cam models of all years. They range from motor mounts, engine alignment, exhaust bracket mounting, primary chain tension, wheels, tires, drive belt tension, almost an endless list. The reason why I'm looking at my crankshaft is the narrow rpm range it occurs. Starting at 2000, being the most intense around 2300 then by 2500 it's gone. Just the rpm that it's in when driving around the back roads where I live. Lately I stay in 3rd gear to keep it in the 3000 range. It's just gotten to be really annoying. Thanks again guys.

 

Awhile back I chased a vibration much as you describe. I went through all the suggestions a couple of forums had. The vib would not allow my to be between 1800-2500 rpm without shaking the faring so bad it was difficult to see the gauges. This was back before I was on here much tho there was a little discussion about in related threads. I finally was able to get a phone conversation with a well known machinist and engine builder. Told him off the symptoms and attempted fix's. Then asked him "short of splitting the cases what would he look at?" His answer was to look at for a broken spring in the compensator or a even remotely loose clutch hub bearing.

We tore it down and found a very small amount of looseness in the clutch hub bearing. The kicker to this was in cleaning the hub I noticed some movement in the clutch basket when moving across the bench.

Washed out the hub in a cleaning vat (safety clean). The rivets that hold the basket to the primary chain sprocket were loose. (there are 6 of them)

Called him back ,told him what I found and he laughed a bit. Rarely had he seen such and asked if I could measure it. Grabbed a dial indicator and it showed .040 lash. He helped me get a clutch basket and all was well.

There is still a vib between 1200-1600 but not anyways near as bad. Serval I have ridden are about the same.

Might be worth a look see

WP

 

Kp877 is the fellow forum member. His thread is long but super informative.
Good luck,
Tom