Evo engine vibration.......ugh..again!!
#1
Evo engine vibration.......ugh..again!!
I've had my 98 fxdl for about 2 years now, its a good running bike, tracks straight, starts all the time and really doesnt give me much problem. I have been researching the vibration these engines have and cant seem to put a finger on whats causing my vibration. Since I bought it its had a new rear wheel and 2 new tires, both motor mounts, the front was replaced with a predator, new intake manifold and all the seals, new carb, mik hsr42, cam sensor replaced and i'm pretty sure the timing is right because it runs and starts great and dont back fire, dyna 2000 ignition and coil set up on single fire, rb racing prostock 2-1, both front brake rotors replaced. My vibration comes in at 2000 rpm and smooths out around 2500. Its the same whether your revving it in neutral or running up through the gears. On deceleration its the same thing, once it comes down below 2500 rpm it starts, gets bad at 2000 then tapers off. I've been through the wheel alignment, engine alignment, loosening the mounts and running the engine for about 30 seconds then tightening everthing back up and nothing helps. On the highway, all the way up to 100 mph, it smooth, engine sounds good, no wobbling, feels real good, so I dont think its a chassis, frame wheel/tire problem. The primary chain tension shoe was replaced and has about 3/8 inch slack when hot, doesnt have any tight spots. I believe my jetting is close cause my spark plugs are brown and i'm getting around 40 mpg. I read articles on other forums about Evos being a smooth running engine with minimal vibration, mine almost wants to shake your feet off the pegs. At 2000-2500 rpm is where it usually wants to be when i'm putting around the neighborhood, so it either stay in 2nd or 3rd gear or go to 4th which would be a little too fast. I've been researching crankshaft problems and runout specs, havent checked mine yet but I would think if that was the case a vibration would get worse with higher rpm or wouldnt hold together for extended 80 mph runs very well. I'm planning a top end tear down this winter and was thinking maybe i'd get the crank done too. I'm still learning about the Evo and would really appreciate anything else you guys out there could offer, I know it has to be a solvable problem that I'm sure someone else out there has had before. I've read where the exhaust mounting could be a problem, but after staring at my bike for hours on end, what I'm seeing is the engine, trans and exhaust is all bolted together, if one shakes, they all shake. So I cant see that being a problem. The previous owner had the stator replaced by a harley dealer, so i'm assuming it was done correctly. I'm not ready to give up, old harley's are the best!!! and i love this bike. Thanks again guys for any advice you could give, I'm sure someone can set me in a new direction in finding the answer. If any other information that I may have forgotten comes to mind I'll add it. Thanks!!!
#2
Join Date: Jan 2011
Location: Haslet Texas
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Do you know what model Rotor and stator the PO had replaced. I just had a new rotor that was no good from manufacturing on my 98 fatboy.. The center splined hub was welded into the center of the rotor (a 2 piece unit) but was not centered properly and because it was not balanced or anything it actually caused a vibration in my crank. Sort of like a bad harmonic balancer on a small block chevy. I have a belt drive so I could actually see the vibration at lower rpm's. I brought it to work and had one of the machinists put it his lathe and it was actually out .022" as measured with a dial indicator. cant trust any thing anymore. Just a possibility......
#6
Join Date: Dec 2010
Location: Coromandel Peninsula New Zealand
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Thing is, some vibrate more than others, my mate's 96 Dyna vibrated like all hell and my 98 Wide Glide didn't.
The easiest fix is to ignore it until something breaks
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Roadghost (08-28-2020)
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#9
Do you know what model Rotor and stator the PO had replaced. I just had a new rotor that was no good from manufacturing on my 98 fatboy.. The center splined hub was welded into the center of the rotor (a 2 piece unit) but was not centered properly and because it was not balanced or anything it actually caused a vibration in my crank. Sort of like a bad harmonic balancer on a small block chevy. I have a belt drive so I could actually see the vibration at lower rpm's. I brought it to work and had one of the machinists put it his lathe and it was actually out .022" as measured with a dial indicator. cant trust any thing anymore. Just a possibility......
#10
Evo engine vibration.......ugh..again!!
Jc I responded to you awhile ago. Might want to read some of my threads. You have the same bike and problem I have. No need to go crazy because it's not going to change. It's going to vibrate in that rpm range no matter what you replace. I checked my crank runout too there was none.