What could cause this?
Stellar HDF Member
Joined: Aug 2020
Posts: 3,182
Likes: 2,225
From: College Station, TX
Yeah, PC5 is a piggyback device that only changes fuel, but not spark timing. So good move on selecting the TTS, you will have lots more options going forward. You should be able to get cylinder temperature, timing and a map of the fuel cells to see where you may be lean or rich with the TTS.
Curious that only that ring was hammered like that. I would have expected more damage, including discoloration on the spark plugs that would help provide insight to what happened.
Good luch
Paul
Curious that only that ring was hammered like that. I would have expected more damage, including discoloration on the spark plugs that would help provide insight to what happened.
Good luch
Paul
Thread Starter
|
Cruiser
Joined: Jun 2014
Posts: 101
Likes: 5
From: AZ
no. That was the only ring that was bad. The other rings look great no signs of cracks or anything anywhere. The plugs are a good color, no signs of pre det. And no piston damage at all, just standard carbon build up. 28k on the stock bottom end.
Yeah, PC5 is a piggyback device that only changes fuel, but not spark timing. So good move on selecting the TTS, you will have lots more options going forward. You should be able to get cylinder temperature, timing and a map of the fuel cells to see where you may be lean or rich with the TTS.
Curious that only that ring was hammered like that. I would have expected more damage, including discoloration on the spark plugs that would help provide insight to what happened.
Good luch
Paul
Curious that only that ring was hammered like that. I would have expected more damage, including discoloration on the spark plugs that would help provide insight to what happened.
Good luch
Paul
Seasoned HDF Member
Joined: May 2008
Posts: 21,174
Likes: 12,745
From: South Carolina
People are trying to offer ideas here, if you don`t want to get peoples responses, don`t ask for help.
Thread Starter
|
Cruiser
Joined: Jun 2014
Posts: 101
Likes: 5
From: AZ
Its crazy. Thats the only think I can think of because when you look in the ring, the missing outer layer. The metal is all grainy, like when you over cook a blade in the forge and it cooks the metal. Its mind f*^%#*+
Club Member
Joined: Mar 2009
Posts: 66,125
Likes: 51,446
From: Niles Canyon Ca.
But like I mentioned before that's a first for piston rings for me. Wow.
Seasoned HDF Member
Joined: Mar 2010
Posts: 21,116
Likes: 7,639
From: Poolville
Totally agree with TwiZted, If it was detonation you would see pepper specs down in the porcelain of the plug and even spots on the top of the piston.. Poor heat tempering or something to that one ring. Cast iron rings is still the way to go with a stock motor though...
Seasoned HDF Member
Joined: Aug 2008
Posts: 5,071
Likes: 1,006
hummm got an electric bike??
prior post:first on the subject of so called ring flutter.
there are two type and a good engineering design is the first weapon to prevent it, the very reason i believe this issue is not that. the history of the hd design does not support that.
as far as dyno runs, you can run ten and get diff results and dips and twist are common and not always accountable to a certain mode of operation. it is a good tool but i have seen "seat of the pants guys" smoke the so called dyno tuned engines.
AXIAL FLUTTER:
this type usually begins at the ring gap and mostly at medium load and high rpm. this would fall into the cruise range but then again, who cruises at high rpm (guilty as charged) and it would tend to rule out hard acceleration since engine demand is high, so it is a crap shoot. on this point, even "IF" you attribute the so called dip in the graph, probably WILL not be there on the road, toooo many variables!
this ring movement refers to the lifting of the piston ring off the bottom flank contact area and as i said begins at the gap as it is the weak link (spacing). this allows motion of the ring ends which in turn sets up a wave pattern that gets transferred to the entire ring, sorta like throwing a rock into the water.
engineering with low ring heights and more pressure on the gap area has a tendency to reduce this flutter.
past engineering, what elese to consider?
1. excessive ring height clearance
2. loss of ring tension which compounds gap loss of pressure, of note: diff ring shapes play a factor
3. mechanical contact (head strike)
4. fuel burn issues, aka, knock and such
5. worn out piston land grooves
6. groove base gas volume too low due to build up behind the rings.
prior post:first on the subject of so called ring flutter.
there are two type and a good engineering design is the first weapon to prevent it, the very reason i believe this issue is not that. the history of the hd design does not support that.
as far as dyno runs, you can run ten and get diff results and dips and twist are common and not always accountable to a certain mode of operation. it is a good tool but i have seen "seat of the pants guys" smoke the so called dyno tuned engines.
AXIAL FLUTTER:
this type usually begins at the ring gap and mostly at medium load and high rpm. this would fall into the cruise range but then again, who cruises at high rpm (guilty as charged) and it would tend to rule out hard acceleration since engine demand is high, so it is a crap shoot. on this point, even "IF" you attribute the so called dip in the graph, probably WILL not be there on the road, toooo many variables!
this ring movement refers to the lifting of the piston ring off the bottom flank contact area and as i said begins at the gap as it is the weak link (spacing). this allows motion of the ring ends which in turn sets up a wave pattern that gets transferred to the entire ring, sorta like throwing a rock into the water.
engineering with low ring heights and more pressure on the gap area has a tendency to reduce this flutter.
past engineering, what elese to consider?
1. excessive ring height clearance
2. loss of ring tension which compounds gap loss of pressure, of note: diff ring shapes play a factor
3. mechanical contact (head strike)
4. fuel burn issues, aka, knock and such
5. worn out piston land grooves
6. groove base gas volume too low due to build up behind the rings.
HD Forum Stories
The Best of Harley-Davidson for Lifelong Riders
7 Surprising Harley-Davidson Products that Are Not Motorcycles
Verdad Gallardo
8 Best Harley-Davidson Motorcycles Ever
Pouria Savadkouei
10 Worst Harley-Davidson Motorcycles Ever
Pouria Savadkouei
Killer Custom's Jail Break Is The Breakout That Refused to Blend In
Verdad Gallardo
Crazy Bunderbike Build Looks Amazing, But Is It Impossible to Ride?
Verdad Gallardo
Harley-Davidson Reveals Super Cool Cafe Racer Concept
Verdad Gallardo
Engraved Rebellion: Inside Bundnerbike's Glam Rock II
Verdad Gallardo
10 Motorcycles You Should Never Buy
Joe Kucinski
10 Things Harley-Davidson Needs to Fix in 2026
Verdad Gallardo
Seasoned HDF Member
Joined: Jun 2017
Posts: 5,315
Likes: 4,272
From: Granville New York
settle down tough guy. All I asked was for another picture a little further away so we can get some perspective. Good luck with the bike...im going outside to was mine after a nice 150 mile ride today.
Thread
Thread Starter
Forum
Replies
Last Post