Corsa line
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Corsa line
I had my scoot all finished not gona lie I broke my new corsa in kinda hard but I had bigger than needed jet had way more than needed oil. And did heat cycles first... So now I have two questions I took all of my profoance parts off to swap them to newer block so my first question is do I need to break in again and second. Inside the cylinder there were two lines about .5cm wide on exaughst port side. There not deep like a soft sieze there not grooved at all it's just darker it's on piston two but hardly. Please give good info
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Check to see if those lines match up with the rings dowel or very near it. Could be rings not seated, or dirt in the cylinder during install or while running. You really have to double and triple check things and make sure its an absolutely spotless work area and engine. Always clean the cylinder out with 2 stroke gas mix and blow out with an air gun,before and after, thats been cleaned well.
If I remember right tho the Corsa ring dowels should be on the back side of the piston towards the boost port.
If I remember right tho the Corsa ring dowels should be on the back side of the piston towards the boost port.
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And anytime you take a piston out of a fully broke in cylinder that the rings have been fully seated/ bedded the cylinder SHOULD be honed and new rings SHOULD be installed. The rings will never seat again like they did the first time. If the engine does not have a full break in on it then you may be ok but I would still be gentle when youre finished reassembling. If you hear some rattling around real bad I would replace the rings or youre going to have a catastrophic engine failure.
If you chose to break you bike in hard and with out reason, I wouldnt expect it to last long. Youll only get out of your build what you put into it. Spend some time building it and itll last some time, or you can take short cuts, be mean to it for a short while, dont follow protocol, and blow your expensive cylinder up real quick.
If you chose to break you bike in hard and with out reason, I wouldnt expect it to last long. Youll only get out of your build what you put into it. Spend some time building it and itll last some time, or you can take short cuts, be mean to it for a short while, dont follow protocol, and blow your expensive cylinder up real quick.
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If lines match up with ring space wat do I do
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And thank you
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If they match up the rings have to be replaced because they didnt seat properly.
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And hone the cylinder. Even though we cant see the depth it is there. If you dont feel safe honing it bring it to a shop theyll do it for cheap I imagine. Make sure its a completely clean area, the cylinder has been thoroughly cleaned, when you install the piston and rings make absolutely sure the ring doesnt catch, and then triple check for air leaks.
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He only has 2 scratches, not seizing, what makes you think its leaking(although it may also be leaking) but leaking is not what causes scratches nor does heat, unless the leak allowed crud in there and its too new to have a large amount of carbon built up in the exhaust port. Junk down in the barrel or rings not properly seated or properly lined up while installing and hung up is usually the reason. If it were seizing it would have more marks or too hot it would have melted parts at the edges of the piston or around the ring landings. Corsa pistons can take some heat, Ive seen them crack but not melt yet.
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Heat isnt going to scratch your bore buddy. Wont happen in a million years. If you have an exhaust leak then it will cook the excess oil and that will build up and cause a scratch from it sucking into the bore, but not on a brand new bore thats just been broke in. It is possible it could have already built up carbon but highly unlikely. If your exhaust temp is 900 it is just seconds from melting a piston if you maintain.
FYI every corsa is already chamfered from Polini out the box.
FYI every corsa is already chamfered from Polini out the box.
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Are you drunk?
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There is no leak no scratch nothing the metal just has two lines of discoloration
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Gotcha, thanks for the info. You make total sense.
Take a pic if you can post it on photo bucket and itll help.
Take a pic if you can post it on photo bucket and itll help.
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Never once did he say he has an exhaust leak or oil coming out of his outlet. Just dark lines on his piston and cylinder. Not a single time so keep telling him about his leak when he's never on e said he has one. Thanks for the info that's useless. Whatever works for you.fdnsman wrote:because the exhaust port's the hottest place in the motor. if exhaust gas temps are 900 degrees, and your leaking air.
put it this way my corsa, it came chamfered from the place i bought it, probbaly helped a bunch. and ive ran a heat cht guage the whole time. doesnt have those marks. but ive bought other kits and they'd scratch their first and destroy that part. if it was leaks, temps bad jetting. that part would look awful with hardly a scratch anywhere else. and this corsa's went through leaks, even a bad one but i took it easy and didnt totally mess it up. and even 100:1 mix's and even me frogetting and doing even more after finding out. hasnt totally screwed it up. ive kept no exhaust leaks cause somoene will leak down test then not put on a good exhaust gasket. their motor will be covered with black around there, and usually about everyones motor, has them exhaust scratches.
why mines not, maybe it's the chamfered ports. that a good thing to do. or maybe its the keeping leaks out and checking my exhaust gaskets after rebolting back up the exhaust. watch itll spit black oilly crap all over your motor. clean it with a rag and go out and start it and watch.
I wouldn't tell people they can do a 100:1 pre mix and they'll be ok. You're just full of good info. And if you're wondering where 900 degree exhaust came from you brought it up not me. You're a strange person.
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Either way the OP needs to get a photo of the piston and cylinder and upload it to photobucket then post the link on here, its the easiest way to help with an issue. 2 dark lines that look like theyve been rubbed on with something hard is 9 out of 10 something down in the barrel. If its caused from heat its called thermal expansion and thats evident by other marks on the piston. A picture is worth a thousand words. Its near impossible to know whats the cause with out the bike being in front of you, at least when someone tries to describe an issue I just tell them bring it down to the shop and have one of my guys take a look at it. Only difference is it costs 60$ to bring it to my shop.
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