HarleyTechTalk

On the '82 FXE I got the front piston broke and thusly I am pulling the engine to split the case and view the extent of the carnage. Upon taking the primary apart I found it has a Fisher FHD-2 harmonic balancer. The engine was an 80" and is now a 93" with a Truett and Osbourn crank that has been shaved and I don't know the stroke.  Bore is 3 5/8".  Clutch is a Primo Rivera. Is this Fisher balancer any good?  Thanks for your help.

If it's 93 cubes, then the bore is most likely 4-1/2". Regarding the "balancer", the general opinion is that they are snake oil. Well, my opinion anyway.

-JW

I believe JW113 meant 4-1/2" stroke. That's a nice combination on a Shovel!

Thanks for your help guys. I had thought the stroke should be 4 1/2"  I have already pulled a grip load of piston/ring/spiral clip stuff from the breather and cam chest.  Waiting on a pinion gear puller so I can split the case and take a look see.  Wondering if I should change to a regular type compensator be cause the Fisher balancer was the cause of all this carnage.  once again,  thanks.

About 25 years or so ago, I mounted one of these on a -90 FLHTC, I was stunned when vibrations increased a lot. Took it off, categorized the thing as "snake oil" and never looked back.
Maybe engine mounts were too soft, and/or stabilizer links were worn, I don't know.
 

My S&S 93"er has been in my 76 frame since 2004. It has never had a compensator on it but does have a spring loaded Hayden primary chain tensioner and a spring loaded secondary chain idler with what looks to be a roller skate wheel (can't recall the name but I got it on eBay.)  Those items and a Rivera Pro clutch took a lot of vibration out of my drive train.

Whenever you see the term "balancer" used in reference with a Harley-Davidson 45 degree single crank pin engine, run. It is physically impossible to "balance" that type of engine configuration. The best that can be done is to optimize the mis-balance to make it as unobjectionable as possible. Either that, or rubber mount the thing and isolate the vibration.

I did a lot of research on these magic balance trinkets way back in the early 90s. Most operate on the concept of a hollow ring full of mercury that is mounted to the crankshaft. I tried through all means possible to get the makers of these trinkets to explain just exactly, in scientific and engineering terms, how their trinket can somehow make an unbalanced spinning flywheel/crankshaft become "balanced". I even asked if they had any blind testing done using accelerometers mounted on the bike (like on the frame or handlebars) to show a before and after measurement and any improvement. None could provide any evidence what-so-ever that their trinket actually did anything. Oh, other than all the testimonials they received from their customers. Which is about as valuable as a Yelp review.

The only, and I do mean ONLY, thing that I have ever found to minimize rigid mount V-twin vibration was to send my flywheels to Darkhorse Crankworks. They have a proprietary method of engine balance factor optimization that I have to say is downright amazing. In 2004 I moved from a EVO Softail to a TC Roadking primarily to have a bike that was ride-able on 700 mile days at 90+ MPH. My Softail, though could do it, it beat the hell out of me in the process. I really missed that Softail and a few years ago got another one, a '92, and while I had the engine apart, sent the wheels to Darkhorse. The result: If my original '91 ran the way this '92 does, I would have never bought a rubber mounted TC. My '92 is smooth as glass (ok, frosted glass LOL!) up to 100mph and beyond. Yes, you can feel a little bit of vibration, but barely noticeable. In fact, there's just a tiny bit there to let you know you're on a real deal Harley-Davidson, and not a Honda Gold Wing.

I then did the same thing to my '77 Electra Glide (which was a total boneshaker), and got similar results. It ain't cheap, but it's not unreasonable either. Money well spent, this process they do really transforms a bike from hard to live with to love to love riding it.

Well, that's my story and I'm sticking to it!

-JW

Well heck, looks like the thing is no bueno.  Wondering if that caused the front piston to come apart. I guess I will make a cool looking clock out of it.  Any suggestions as to a top notch compensator?  Thank you all for your help.

I modified an evo comp for my shovel. You have to shorten the nut and cut the threads deeper.