OK, that's definitely an EVO engine.. but which one is the question...


I am not an expert, hopefully someone with more knowledge than I have, will see this and chime in...

From an old, faulty memory, notes I made in one of my old EVO service manuals, and from consulting two HD EVO parts catalogs;

The was an early EVO engine with a crankcase vent from the side of the engine by the oil pump, up to the aft side of the air cleaner.

There was a later EVO engine with a crankcase vent similar to the twin cams. It had umbrella valves in the rocker arm base cover, that lead to actual "breather bolts" part #3577 in the heads.

There were some other differences between the two, including a difference in the cam chest end of the crank, but I can't remember, and couldn't find specifics on the other changes.


The pictures of your bike show an external breather system from head breather bolts. Nice bike by the way.... That tells me that you have the "Later" EVO engine.


Sadly, I don't know when these changes happened. I don't know if there was just one big update/change to the EVO engine, or several over a few years...

My HD Softail Parts catalog for '87-'90 bikes with the EVO engine, showed the early EVO engine parts on all models. My '97 HD Parts catalog for '97 bikes, showed the later EVO engine parts for all models. That means the changes were made between '90 & '97...

So at least we know that your EVO engine is newer than 1990...


As to the crack, I am neither a machinist or metal worker. I suspect a very knowledgeable welder/machinist, could weld that up, then drill a new hole.... But that is just a guess on my part. I also believe a repair like that would require disassembly of the engine...


I'm not trying you confuse you with all this info.... I offer it to educate you about what you need to know to get the right parts ordered for that engine, without wasting money on the wrong parts...

I hope you find some of it helpful....

Good luck with your project...

 

I’m not sure if it was confirmed about where the number is. I wandered out to the shed to take a look at my 99 and it is on the primary side right about level with the shifter linkage like the twinkies.

 

Thanks for that confirmation.. That's where I thought it should be... Been awhile since I've seen an EVO up close. I sold mine in the 90's

However, in one of his pics of that area, there doesn't seem to be an EIN......

Maybe it has custom cases...

 

Hello

I really am In a Jam I just bought a 97 Bad Boy in Germany and am now about to legalize it in Portugal...nightmare

Well I'm filling out the papers and see the engine vin has nothing in common with the vin on frame

Engine VIN ☆BMLX031161☆can someone decode please 🙏
the other number on cases behind gear shifter is 1599315011

 

EIN (Engine Identification Number) of BMLX031161:

BM = FLSTF, Softail Fat Boy

L = 1340cc (80") Evolution Engine

X = 1999

031161 = Production numbers- They should match the last six numbers of the VIN on the bike shipped from the factory with that engine.


It would appear that engine (or at minumum the left side case) was taken out of a 1999 Fat Boy (the last 6 digits of the VIN were 031161) and installed into your 1997 Bad Boy.