Help.. flipped piston
Road Warrior
Joined: Jun 2008
Posts: 1,428
Likes: 0
From: Rescue, VA
Ok, who wrote this passage first:
According to S&S here is what they have to say about the affects of lugging your engine.
"Lugging an engine means putting the engine under an extremely stressful load. A common way to lug an engine is to operate it at an extremely low rpm while the transmission is in a higher gear (for instance, leaving the transmission in fourth gear when it should be in second or third where engine speed is better matched to transmission speed). Lugging causes extreme stress between the rear thrust faces of each piston and the cylinder walls. Small bits of piston skirt can break away causing the rear surface to scuff. The best prevention for lugging an engine (either old or new) is to downshift to a lower gear where the engine runs more freely, and the transmission assists the engine in delivering peak power to the rear wheel."
steel thunder
It is also important not to lug the engine. Lugging an engine means putting the engine under an extremely stressful load. A common way to lug an engine is to operate it at an extremely low rpm while the transmission is in a higher gear (for instance, leaving the transmission in fourth gear when it should be in second or third where engine speed is better matched to transmission speed). Lugging causes extreme stress between the rear thrust faces of each piston and the cylinder walls. Small bits of piston skirt can break away causing the rear surface to scuff. The best prevention for lugging an engine (either old or new) is to downshift to a lower gear where the engine runs more freely, and the transmission assists the engine in delivering peak power to the rear wheel.
According to S&S here is what they have to say about the affects of lugging your engine.
"Lugging an engine means putting the engine under an extremely stressful load. A common way to lug an engine is to operate it at an extremely low rpm while the transmission is in a higher gear (for instance, leaving the transmission in fourth gear when it should be in second or third where engine speed is better matched to transmission speed). Lugging causes extreme stress between the rear thrust faces of each piston and the cylinder walls. Small bits of piston skirt can break away causing the rear surface to scuff. The best prevention for lugging an engine (either old or new) is to downshift to a lower gear where the engine runs more freely, and the transmission assists the engine in delivering peak power to the rear wheel."
steel thunder
It is also important not to lug the engine. Lugging an engine means putting the engine under an extremely stressful load. A common way to lug an engine is to operate it at an extremely low rpm while the transmission is in a higher gear (for instance, leaving the transmission in fourth gear when it should be in second or third where engine speed is better matched to transmission speed). Lugging causes extreme stress between the rear thrust faces of each piston and the cylinder walls. Small bits of piston skirt can break away causing the rear surface to scuff. The best prevention for lugging an engine (either old or new) is to downshift to a lower gear where the engine runs more freely, and the transmission assists the engine in delivering peak power to the rear wheel.
Extreme HDF Member
Joined: Dec 2007
Posts: 13,402
Likes: 941
From: Illinois
I see scoring and scorched over heated areas. Could be from an engine low on oil or ran as hard as as it would go prior to a proper brake in.
It does look like it received brutal use and abuse.
When I was young and stupid I blew up engines and transmissions often. I knew whose fault it was and just called the repair cost " entertainment tax". Same for the traffic tickets.
It does look like it received brutal use and abuse.
When I was young and stupid I blew up engines and transmissions often. I knew whose fault it was and just called the repair cost " entertainment tax". Same for the traffic tickets.
Last edited by lh4x4; Jan 29, 2014 at 04:29 PM.
Outstanding HDF Member
Joined: Apr 2010
Posts: 2,477
Likes: 14
From: Western MD
yeah, I don't think that motor was broke in and or tuned right before beating on it.
though it doesn't look like the piston burned down from being to lean, by looking at the combustion chamber you can see detonation marks in it.. high rpm, excessive pinging for whatever reason, wrong timing, lean, wrong fuel etc.. spelled the end for this motor from the beginning.
Road Master
Joined: Oct 2013
Posts: 924
Likes: 0
From: Elgin IL
Ouch!! I have to agree that I think possible oil starvation and excessive RPM in maybe 1st or 2nd gear. Was there oil in the bike and how much ,was the oil pump functional for that much damage it had to be making one hell of a noise just before failure, to me I would say it was deliberate, maybe he wanted to see how high and how long he could rev it before BOOM !!
Club Member
Joined: Mar 2009
Posts: 66,122
Likes: 51,434
From: Niles Canyon Ca.
yeah, I don't think that motor was broke in and or tuned right before beating on it.
though it doesn't look like the piston burned down from being to lean, by looking at the combustion chamber you can see detonation marks in it.. high rpm, excessive pinging for whatever reason, wrong timing, lean, wrong fuel etc.. spelled the end for this motor from the beginning.
though it doesn't look like the piston burned down from being to lean, by looking at the combustion chamber you can see detonation marks in it.. high rpm, excessive pinging for whatever reason, wrong timing, lean, wrong fuel etc.. spelled the end for this motor from the beginning.
Outstanding HDF Member
Joined: Dec 2012
Posts: 2,699
Likes: 520
From: Palm Coast, Florida
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