Hey, Just baught a 2000 Fatboy, it was a win win for me. it was cheap and needs work. since Im broke and love to tinker with things I figured I couldn't pass it up. I have ridden the bike for about 40 miles so far, and will continue to ride it until I tear it apart to check stuff out or it dies on me. the engine is vibrating, I know it's a solid mount engine and vibes are normal, but this these vibes aren't normal, they feel good but they are not normal, at idle the engine sounds find, shakes the bike a tiny bit and keeps puring like normal, once you take off it starts vibrating real bad and making all kinds of noise, if I keep the rpms low the vibes aren't too bad. the higher the rpms the worse the vibes get. If I try to reach the normal shift rpms the whole bike is shaking and raddling and making all kind of noise, hard to say what the engine sounds like cuz all I hear is the tank and foot boards vibrating against the frame and so forth, I am thinking it's the counter balance, the Manual that I have which came with the bike only tells me how to check the counter balance as I am building the motor from scratch, and is a litle confusing. from what I gathered from the manual I have to split the engine case, if this is true no big deal I will work on that, but do I need to split the case just to check the counterbalance or is there another way to check the counterbalance and then if it is out of alignment split the case to fix it. I am mechanicly inclined it's what I did before the big lay offs, I just worked on things with 4 wheels, a point in the right direction and this fatboy will be on the rode vibrating normally.

Thanks
Tired_Bird

 

Below 3,000 RPMs the counterbalancers should keep the engine relatively smooth. Past 3k, they get overwhelmed fairly quickly. It's used, so no idea what the previous owner did to the bike. The only way to physically check the counterbalancer assembly is to remove the engine and split the case. The balancer assembly is chain driven and it's huge. I have heard stories of the chain tensioners going bad, but who knows?

There have been a select few who have removed the balancer assembly and true/welded the crank to help the vibes and remove the excess loss of power from the counterbalancers. Who knows, maybe the previous owner did that?

 

If you haven't already tightened all the motor mounts, try that, especially the top motor mount

 

O yea it's deffinitly used, that's why the name Tired_Bird came to mind, its a 2000 fat boy and the bike has 108,567 miles on it. he had papper work showing the engine was rebuilt at 90k with a 95 cu inch kit installed. I will double check all the motor mounts, and anything else you guys can think of before splitting the case to check the counterbalance. he could have true welded it together but I am thinking he didn't, the bike was mainly ridden by his wife and I believe the vibes started somewhere on there trip to reno. they rode it back the whole way with the vibes. time will tell I guess. If you guys come up with any other ideas that I should check let me know. if you know of a good article on splitting the case to check the Counter balance let me know too, the manual I have will do the trick but it's kind of confusing.

Thanks
Tired_Bird

 

correct me if im wrong but i was under the impression that the counterbalance wasnt added to the engine untill they went to 96",and is called the 96B engine..

 

I believe even back in '92 the softails had a counter balanced engine. But then again I may be wrong, and if I am it won't be the first nor last time ....

 

my 03 has an 88b engine

 

all twin cam softail motors are counterbalanced,unless they are like mine !!.evo motors were not counterbalanced

 

The twin cam came out to replace the old EVO 1340 moters..So the twin cam started in late 1999 so The 88B was in the 2000 to 2006 softails.....then they went to a 96B from 2007 and up. All softails for 2000 to 2006 have the 88B and 2007 and up a 96B....The EVO softails started in 1984 to 1999 they were great moters but not counterbalanced...

 

That twin cam has 108,567 miles on it so it could be many things........When he did the95 cu inch kit theres a good chance all he changed was the jugs and the pistons but the bottem end still can have near 110,000 miles on it. With that many miles maybe its time to tear it down and go over everything...