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Re: New problem....

Posted: Wed Jul 11, 2012 7:11 am
by bikeymikey748
What Larry just posted made me think, what about heat seizure? Rohit, did you set the ring end gap to spec?
A quick look with a borescope could be usefull. Look for galling on the bores.

Re: New problem....

Posted: Wed Jul 11, 2012 7:36 am
by Rohit
"A quick look with a borescope could be usefull. Look for galling on the bores."
Thanks to everyone for replies..,,
Sir can you pls tell me how to look with a bore scope.... And what do you mean by "Look for galling on the bores".....
Thanks

Re: New problem....

Posted: Wed Jul 11, 2012 12:17 pm
by bikeymikey748
Rohit,a borescope is like a flexible periscope that you pass through the spark plug hole. It allows you to see inside the cylinder, in your case, you'll want to pay attention to the cylinder walls. Look for scoring/galling (scraping). Note too, if you see any indication of,localised, overheating on the walls. I sure hope you don't.
Two stroke motors are known for 'heat seizures'. Sometimes, on newly rebuilt motors, rings ( that didn't have their end gaps set to spec) expand quickly and lock in the bores. At times, they micro-weld to the walls. The welds are quickly fractured, and leave behind tell-tale scoring.Typically, the pistons will eventually lock in place. Shortly after, as the cylinders cool and parts can contract slightly, some clearance returns. The motor will start, overheat,lock, and cool....the process repeats again. This will only go on so long before the pistons/rings lock permanently.