help, need info on piston, rod specs

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ohiofordfan

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hello, i have a sirio .23 and was putting new stater on it. while turning the flywheel it felt like it was gettin compression twice. thats the only way i know to explain it.i checked all my other engines and none of them do it. so i took it apart knowing something is wrong. the rod to crank bearing is tight but for the 1/4 turn while the piston is on top the piston stops. the first tight feeling is when the piston stops up top and the second tight feeling is when the piston starts coming back down. so i thought wrist pin or something. took it all the way apart the rod seems tight on the wrist pin but maybe the wrist pin is a little sloppy in the piston. i don't know which part is wrong. it moved alot more in the sleeve(cause the compression), and its hard to tell with it apart. i hope this makes sense to someone. i think this happened because of a flooding, rotostart, drill situation. any help would be appreciated, i would liketo fix because i just went over my first gallon and trully love the engine.
 

olds97_lss

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What does it do with the glow plug out? You sure it isn't just getting a tight seal and causing suction on the down stroke? With the con-rod disconnected from the crank, how does it feel when you spin it?
 

ohiofordfan

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hello, it had the same feeling with the glow plug out. the crank feels great and everything looks good. while spinning crank with engine together(no back plate or glow plug) is when you feel it get the tightness twice. with glow plug in it was the same but worse(tighter). from what i see the wrist pin has a little play in the piston. is that right? the conrod slides on the wrist pin but is tight like it should i think. i wondering if in needs piston or wristpin. maybe bearing in the conrod/wristpin connection? thanks again

i just thoght of another way to explain: with the backplate off and the exhaust manifold off. spin the crank and the piston gets to the top and stops at about 11:00. keep spinning crank, piston does not move again till about the 1:00 position and then starts coming down. the tight feeling is at the same points, 1:00 and 11:00. hope this helps.
 

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