Early this summer I ran into a rider that had a 91 evo like mine and they told me to watch out for the tappets going bonkers! Well three weeks later guess what, horrible sounds coming from the engine I pull over shut it off let it cool then start it again, quiet as a mouse! Sounded great, so I called a HD shop, they never heard of such a thing, another guy said change the oil and look for stuff. I changed the oil, nothing in it, so I rode again very cautiously. I went 10 mile and turned arround then it hit again and didn't stop all the way home.
After a tear down I found that one tappet had lost needles and had turned sideways and screwed up the cam, rotary vent and lifter block. I found some SE tappets and bought new blocks and cam cleaned the whole case out good as well as the oil pump. The rotary vent had gotten some needles in it and it screwed up the casting so I put in a reed valve.
My question is, why did it happen and is it going to happen again!?!?

 

Ive heard that 45K miles is a good time to inspect and replace tappets. my dads 94 FL had about 46 on it this year so I bought him some S&S tappets and a cam just as preventive maintanence.

the trunions (bearings that blew out on yours) are a little on the small side, so to fix this you put in a tappet with a larger trunions like the Jims (SE) or S&S to add life to your engine.

 

I has the rear lifter roller bearings come apart on my '93 ultra. made a mess of the motor. knocking and grinding to the point a reman was needed. I had 49,923 miles on it when she blew. I've heard from several people that around 40k is the time to change out the lifters.I believe them now. you'll also hear guys went 100k with no problems but seeing what happened to me, I would'nt risk it.my2cents.,,,