my bike is a 2005 FLHTI screamin eagle air cleaner with a stage 2 remap and later model breather tubes. a vance and hines 2 into one. did a compression test 150 in front 60 in the rear. pulled the cylinder and found this piston in this condition. any ideas what happened? was headed from Victorville early morning freezing cold my bike was covered in ice when I headed out. got about 60 miles hauling *** down the Cajon pass. lost power about the 10 fwy noticed the plug was gone and I was smoking didn't notice if it was from the blow by all over my pipe or if it was coming out of the pipe. other than the air cleaner and the pipe and a stage 2 remap the bike is stock 40 k on the clock. any input is appreciated. running lean? do i need a tunable system like a power commander? I really don't want to replace this and have it all happen again...
thanx
Tim

 

Ouch!

You said the plug was "gone'? explain further. Looks like pre-detonation or a piece of something busted a hole in your piston crown and then combustion gasses did the rest!

 

This is my thought the aluminum was cold and in the process of the cylinder getting warmer and back to a round bore(they are not when cold ) it bound up just a little on the piston causing this.I do not see any signs that it has been scuffing/scoring prior to this.One more thing,did you have any ice or moisture around the air cleaner as that getting sucked in to a hot combustion chamber would do that as well.

 

Looks to me like the ring gaps are lined up. They are supposed to be staggared.

 

Rings are lined up on motors all the time when they come apart, NOT the cause of this!

Is that the front or rear of the rear piston, and how far( for those of us that dont live in the area to know where the 10 is) where you from you point of origin? ie how warm was the motor as you were hauling *** in the freezing cold?

 

I live in huntington beach so cal. commute to Los Angeles everyday 120 miles round trip or more a day. I got some time off went for a long trip to panamint city ghost town near ballarat , panamint city in the draw in the background.
220 miles away rode about 50 miles of dirt roads then 130 miles to my buddies house in victorville california next morning there was ice all over my tour pack and seat. started and seemed normal let it warm up rode over to harley dealer which was closed and then headed home stopping just to get fuel

 

What were the valves like? Was one missing or maybe a hunk of sparkplug got shot in there from the compression stroke. It looks like it took a couple of revs to do the damage. It took awhile for the damage to get through the lower compression ring after it shot though the first. See how it spread out between the rings. Also looks like something came out the oil ports under the oil ring, molten aluminum maybe as it got into the oil rings at each hole. Wonder how the lower end is. Please keep us up to date on what was found and the final analyis.......I sure am interested in the result!!

 

What were the valves like? not leaking a bit look great Was one missing or maybe a hunk of sparkplug got shot in there from the compression stroke.nope. it looks like the melted aluminum is stuck to the top of the piston It looks like it took a couple of revs to do the damage. It took awhile for the damage to get through the lower compression ring after it shot though the first. See how it spread out between the rings. Also looks like something came out the oil ports under the oil ring, molten aluminum maybe as it got into the oil rings at each hole.it looks to me like it needed oxygen so bad that the air coming from the crank case thru the small holes that feedthe oil rings thru the piston the middle hole show slight sign of enlarging. Wonder how the lower end is. me too but i have four kids three moms and child support to the maximum penalty of the law. I am throwin it back together with some take offs I found on craigslist hope it works. thanx for all your help im doin it with a coat hanger baby it'll only hurt for a minute.

 

Same thing happened to my wife's '05 Deluxe. We left the Lake of the Ozarks early in the morning 70 degrees. I got out ahead of a couple of miles then backed off waiting for her to catch up. When she didn't show I turned around and found her on the side of the road. She said it started cutting out and sounded like it was running on one cylinder. The oil tank plug had also blown out covering the bike with oil.

I pulled the plug wires to see which cylinder it was, sure enough it was the front one. We were lucky, a friend of ours had followed us down in a pickup. We picked it up (a bitch) and hauled it home. I took it apart and the piston looked just like yours. The valves were ok! To this day I don't know what the hell happened, but I had the cylinder bored 10 over and had a valve job done on that head. I put it back together, started it and drove it straight to the dealer and traded it off. When they sold it they gave the new owner my number in case he wanted any of the parts I had taken off. When he came over I told him the story. To this day it's running great.

 

Are you sure you didn't put diesel in insted of gas? My uncle, who owns a trucking company, did this once. He is used to grabbing the diesel pump for his trucks so he did notice until a few miles down the road. One of his pistons looked like yours.

Dave