So I took in the 81 FLH - I bought it for a rider to go back and forth to Duluth (150 miles) - had top end noise - opened it up and saw it spit a spiral lock - scored both pistons - found a piece of the lock in the breather - found the front rod was loose as well - so down to the wheels we go - I have trued many ironhead wheels - but this is new for me - and I have a couple questions - first - why are the wheels only drilled on the outside? all my ironheads were drilled inside - second - this is an 81 - how do I know which crankpin I need??? - the wheels are -78 casting - I know that the taper on of the crankpin changed in mid-81 - so how do I know? third - should I upgrade the pinion bearing to the 1 piece type - instrad the original 2 row type - ferg

Pics fist

 

here is the crank pin - wow - what a mess - so this is a commonized pin - the oil passage is 90 degrees from the key on the pinion side - also the nuts are 1"-20 w/ no locks - the cages are all scuffed up - the thrust washers have a .120 groove in them - the bearings were .1871 - this is .0004 under stock from wear - looks like I've got work to do - it is 35 degrees in my shop though

 

Did the did bearing fail and take out the crank pin?

Hence the flat spot in the pin....

 

Don't know if S&S still makes them, but they used to make a drop-in set of crank pin and rods. You could check with them to find out.

 

Don't like the looks of that taper and keyway in the flywheel, may explain why the bearing cage & thrust washer was eating themselves. Running to low an idle and dirty oil will scallop out the crankpin like that , usually see that with the 3 hole pins.

 

put a new oil pump in and do the hi speed gearing

the crank pin is OEM harley one hole

we convert the one piece bearing to the early style 2 piece in my shop since they came along in the 90s more choices and the early bearing i have seen them 30 years in service and in the 90s seen the one piece fail

and twist is right those wheels have rough looking tapers and the key way is chewed my guess it has the wrong crank pin in it BUT i cant tell with the picture for sure
buy a set of the RPLS rods complete pin rollers all fitted from japan

breather may need a re bore - scrup the oil tank and throw away all rubber oil lines hi carbon steel will come back to bite you

 

the wristpin was toast as well - I would assume the piston was slapping side to side - lots of debris in the oil - motor only has 17000 miles - pistons were 10 over - my guess is the guy that did the last topend did not check the lower end - funny - there was very little play in the rods at the top and bottom of the stroke - only at the 1/2 stroke did the rod show the .10 play

 

found that as well with a one side grind out like you have i could only get it to make noise at 40 - 45 when you just unload the throttle in like 3 or 4th gear

 

Yup, just did an FXR that had the top end done by a high end shop in CA. Brand new top w/ Branch #4 heads, they had it for 2.5 years and couldn't figure out the abnormal sound, (rattle, no load, while coming back to idle). It had been apart so many times I used every Keen-sert and Heli-coil in the shop. I heard it and told him "The crankpin is spalling". He was doubtful after dealing with folks who are supposed to be much smarter than I, I told him if the pin wasn't bad, he could pay me to keep looking, or take it from the shop, no charge. After a little time on the Sunnen hone, a new pin and bearings, it was good to go. Customer could not wait to get back to San Diego and let the experts know that a stupid cowboy in SD knew exactly what was wrong.

 

Hey rancho - no question is stupid and people who consider themselves experts are novice thinkers at best