Break-in the CY .29cc BB head

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Flag this messageRE: dot on piston headThursday, July 2008 7:02 AM
From: "Dave's Discount Motors" <[email protected]>

Yes, it has to do with the gas flow, it will not run if it is incorrect, make sure the dot faces the exhaust port or engine will not start or run.

Brad


From:@yahoo.com]
Sent: July 2008 12:23 AM
To: [email protected]
Subject: dot on piston head

Hello,

I have a question why does the dot on the piston head have to go to the exhaust port side?
Will the engine still run if you 180 the dot? does it have to do with gas flow?
Click to expand...

Unless they are handing out the wrong info.....:no::blush:
 
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Ok But I don’t agree. Tell you can give me a good explanation of the reason it will not start, I will still believe it will start.
Don’t ask me to try it. I am not willing to risk my engine to proof something to me, I already believe in.
 
IF the piston and ring are installed backwards, ie dot to teh intage and ring gap to the exhaust port, the motor WILL Start and RUN! BUT the exposed ring gap dropping in and out of the exhaust port will certainly cause problems and breakage.

as the ring gap drops into the open exhaust port, the ends of the ring can/will eventually stick out and catch the top of the exhaust port or the bottom, either way destroying the piston/ring and likely the cylinder in the process.

if you look at the intake port, you ll see a tear drop looking piece in the center of the intake port. that is where the Ring Gap rides as it drops into and out of the intake port. so with the ring gap being held inplace by that teardrop part of the intake port, the ring ends CANT pop out beyond the edge of the cylinder, so there for they cant catch on the top or bottom of the port like they will when backwards.


now if the piston and ring are installed properly, but you put the carb on the exhaust port, and the pipe on the intake port, then no, the motor should not start or run. but just having the piston/ring on backwards yes it will start and run and certainly damage the motor.
hope this helps a bit.
 
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