Matt Vandart Posted September 10, 2010 Report Share Posted September 10, 2010 (edited) Here are pictures of a TZR 250 head (3ma). Notice one combustion chamber is f**ked. Now I know what I think it is but I just want some confirmation/other opinions without any influence of my opinion. Thanks Edited September 10, 2010 by Matt Vandart Quote Link to comment Share on other sites More sharing options...
josh barker Posted September 10, 2010 Report Share Posted September 10, 2010 picture isnt working Quote Link to comment Share on other sites More sharing options...
PeanuckleJive Posted September 10, 2010 Report Share Posted September 10, 2010 to the people who made the effort to just copy and paste the URL, it does work. I can't tell much from the photo, any chance you could get one from an angle so we can see the depth of the damage? Quote Link to comment Share on other sites More sharing options...
Si-man Posted September 10, 2010 Report Share Posted September 10, 2010 Pistons exploded causing it to pit like f**k. Quote Link to comment Share on other sites More sharing options...
Token Posted September 10, 2010 Report Share Posted September 10, 2010 Looks to me like somethings been rattling around in the chamber for a while, what was the condition of the piston and cylinder walls? Quote Link to comment Share on other sites More sharing options...
Matt Vandart Posted September 10, 2010 Author Report Share Posted September 10, 2010 Pistons exploded causing it to pit like f**k. Any ideas what the particular failure mode was? to the people who made the effort to just copy and paste the URL, it does work. I can't tell much from the photo, any chance you could get one from an angle so we can see the depth of the damage? Unfortunately no, it has been sent by email for my analysis. Looks to me like somethings been rattling around in the chamber for a while, what was the condition of the piston and cylinder walls? Correct half the piston. What I am trying to determine is the reason the piston failed. There is a considerable amount of shit consisting of carbon/aluminium mix on the chamber you can see the build up in the lower right quarter. I think some of this is pressure welded piston stuck to the head but am at a loss as to what the carbon is doing there. Quote Link to comment Share on other sites More sharing options...
Token Posted September 10, 2010 Report Share Posted September 10, 2010 Correct half the piston. What I am trying to determine is the reason the piston failed. There is a considerable amount of shit consisting of carbon/aluminium mix on the chamber you can see the build up in the lower right quarter. I think some of this is pressure welded piston stuck to the head but am at a loss as to what the carbon is doing there. I'd imagine that if half the piston started jumping around in the cylinder your gona have a little issue with the combustion process, a incomplete combustion would produce some black stuff perhaps? Quote Link to comment Share on other sites More sharing options...
Muel Posted September 10, 2010 Report Share Posted September 10, 2010 Blown a hole in the top of the piston by the looks of it. There is a motorbike thread already Matt. Quote Link to comment Share on other sites More sharing options...
trialsmax04 Posted September 11, 2010 Report Share Posted September 11, 2010 Right, have seen this before on bikes. Have a look on the piston, in the ring recesses. There should be a small pin in the recess to allow ease of fitting and removal of the piston into the cylender. Under extream heat thease pins can fall out / melt. In which circumstances look at the barrel and look for a long score mark. This can leed to bits being chiped off the piston/ barrel surface. Ive also had a piece of the ring break off before which can also cause such damage allong with bits such as piston clips damaging. edit: Changed my mind looking at the oily residue on the right chamber and none on the left. Looks like one carb was blocked or they wernt in sync. This causes one chamber to run far too lean and if the piston has a nice hole in this is your problem Need to get out more Quote Link to comment Share on other sites More sharing options...
DrDoom Posted September 11, 2010 Report Share Posted September 11, 2010 http://jforjustice.co.uk/banksters Quote Link to comment Share on other sites More sharing options...
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