I am very rural with nobody local to ask this stuff. What are the differences in the Evolution engines in time frames, such as 1984-1986 / late 1980's / Early 1990's / Mid 1990's / amd then 1998 / 1999? These would all be for carbureted versions. You can voice opinions as to which is better or worse, but I would prefer to let people make up their own minds; I just want to know the differences, pros and cons in say:

1. The Bottom Ends

2. The Oiling System

3. The Breather System

4. The Ignition System

5. The Charging System

 

1. The Bottom Ends - '84-'86 were 5 piece flywheels same like a Shovelhead. '87-'88 were 4 piece with the sprocket shaft made to the left wheel. '89-up were 3 piece with both sprocket and pinion shaft made the the wheels and a replaceable race was added to the pinion shaft for the pinion bearing. '84-'90 had a steel insert in the left case for the main bearing. '91 up the bearing bore was machined into the case.

Pinion shaft hardware (oil pump drive pinion, cam drive gear) changed in '91-'92 and again in '93-up including a different end nut. Cylinder studs changed numerous times but except for the earliest version, they're basically all the same.

2. The Oiling System - Oil pump bolt pattern changed in '92 and they used various pump covers and bodies to accommodate different models but the oiling system never changed.

3. The Breather System - In '92 they started using top breather heads with adapter "plugs" in the air box mounts. They were breather heads on a bottom breather engine. Heads are all the same but in '92 they started drilling and tapping for top breather arrangement. The rocker boxes / covers will interchange but are specific to top or bottom breather heads. That is, they'll bolt on and you can use top breather on a bottom breather but not vice-versa.

4. The Ignition System - Other than the wires and connectors for the wire harness, no change

5. The Charging System - '84-'88 22 amp. "89 -up 32 amp on some models. Some later models had a 38 amp with different regulator and stator. They will all interchange.

Starter totally changed in '89. Clutch changed from dry in the first ones to wet '84-'89. Changed style in '90 and again in '98. Transmission parts changed a little, mostly the input shaft and main drive gear. Lots of other little changes depending on the model thru the years but those are the major ones... assuming I didn't forget one or two. If I did, someone will surely call me down and that's OK too

 

Thank you very much for that very detailed summary! It kind of puts me in a tough spot. I am looking pretty hard at a 1992 Softail. There appear to be a lot of potential complications with a 1992. I have a 1984 Shovelhead and it has it's share of one year only messes. Did the changes for 1992 apply to all 1992 models or is it a phase in with the depletion of existing parts as on most Harleys?

I have a 1998 Dyna Wide Glide FXDWG. I just do not care for the Dyna frames. I missed out on a 1999 Softail. It may be a good miss though! I don't know if it was carbed or Fuel Injection; It also had a kicker kit added and no idea if it had Ignition changes with that. Again, probably a lucky miss.

 

92 and up things were pretty well commonized for the evo engines and drivetrain in general, they played with the head breathers a bit more but that's about it. Earlier years had a lot of changes including starters and clutch's and you really need to know what's what when playing with them.

 

There never were too many local guys with Evos around here. But of the few that were around here, I know of two that broke the shafts on the crank wheels. The one I know was on the left side of the engine, it was hot rodded quite a bit; the other one I don't know which side it was on and can't remember if it was a stock bike or not, nor if it was run hard or not. Which era was this most common on for busting cranks. Now that I think of it, I believe the one was a broken crank pin.
Is the 1992 and later bottom end a good one, best one, or what?

 

Thanks t150vej for that detailed information.
I had no clue the flywheels changed so much.

 

I am Unaware of any "mess" in 1984, unless referring to "Early vs Late". That was simply the Clutch!!!
IMHO the 1984 Shovelhead, with a real Shovelhead Clutch, was The Epitome... I am in Lust with Late Shovels....

 

Racepres if you owned a 1984 FXEF you would know the mess. Most retailers do not believe it exists. They were a mid year introduction and not in many of the brochures, manuals , catalogs, etc. I sometimes have to order 1983 parts as some retailers try to sell me Evo parts for it because it is a late 1984.

Yes the clutch is the later diaphragm (wet) clutch. But the main issue is when you type year and model or search the drop downs on a site for the model it never comes up - 1984 FXEF.

 

I still don't see the "mess" If ya know what it is...and ya know "late" ...No Problem... Kinda like the 1985 and 1986 4-speed Evos.. The Only "mess" is People's minds... Ya know what it is... act accordingly...Bike is Not a "Mess" Even if I do Detest and actively avoid those Clutches!!! Clear until???? 1988 maybe???
Don't/Won't own one...Personally.

Edit; If yer talkin online micro fiche...Haven't had Shovelheads...4-speed Shovelheads...for an Eternity!!! Factory Service manual, Factory Parts manual...Priceless!!! and Available.