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Old 07-01-2008, 06:15 PM   #1
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my engine's flywheel will not move without getting stuck. when i took the heatsink head off, i notice the piston sleeve sliding upwards when i turn the flywheel. seems like the piston is rubbing against the piston sleeve's wall.

it only rubs or get stuck when the piston sleeve is near the top of the piston sleeve's wall.

this engine had been working fine-running it at around 220 degrees.

is this fixable without buying a new piston and sleeve?

something got deformed, maybe it was the coil that came off the last glow plug.
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Old 07-01-2008, 07:14 PM   #2
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Quote:
Originally Posted by poochy View Post
my engine's flywheel will not move without getting stuck. when i took the heatsink head off, i notice the piston sleeve sliding upwards when i turn the flywheel. seems like the piston is rubbing against the piston sleeve's wall.

it only rubs or get stuck when the piston sleeve is near the top of the piston sleeve's wall.

this engine had been working fine-running it at around 220 degrees.

is this fixable without buying a new piston and sleeve?

something got deformed, maybe it was the coil that came off the last glow plug.
Sure its not just the pinch??? Its supposed to get stuck when its arriving to the top, should still slide if enough pressure is applied. If the sleeve comes out as the piston is moved upwards then this is a good sign that it still has compression which is good. Try taking it apart and inspecting the piston and inside the sleeve... Hope this helps.
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Old 07-01-2008, 07:37 PM   #3
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ill take it apart tomorrow. i just cant figure out why it would just pinch.
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Old 07-01-2008, 08:07 PM   #4
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is it new, how much fuel do you have through it
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Old 07-01-2008, 09:13 PM   #5
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This is normal. It's called the pinch. Also did you notice this when the engine was cooler than normal. You will notice alot more pinch when the tempiture is cooler. I have a hella of time starting my engine early in the morning on cool days.
You also may need to breakin the engine a little more.


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Old 07-02-2008, 07:16 AM   #6
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no, its not new at all, about 2 gallons through it.

all of the sudden it pinched.
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Old 07-02-2008, 06:14 PM   #7
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so i took the engine apart. with piston and cylinder taken out of the bulk-i noticed i could not slide the piston to the top of the cylinder. do i need new cylinder or new piston or both?
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Old 07-02-2008, 07:33 PM   #8
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From what you are descrbiing there is nothing wrong with your engine. If you have a good pinch after two gallons that is a sign of a good engine. If your piston can go all the way to the top of the sleeve then you buy both the piston and sleeve plus connecting rod. Or just get a new engine.
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Old 07-03-2008, 11:43 AM   #9
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Quote:
Originally Posted by poochy View Post
so i took the engine apart. with piston and cylinder taken out of the bulk-i noticed i could not slide the piston to the top of the cylinder. do i need new cylinder or new piston or both?
You need to replace the piston/sleave when you CAN push the piston to the top! Unless you see physical damage to the piston or sleave, what you are describing is a GOOD thing. Piston and sleave are sold as a set and are generally not available seperately.
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Old 07-04-2008, 06:28 PM   #10
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1) Have you run a gallon with it?
2) Do you use ARO after running it?

Remove glow plug, Pull start, does engine seize? Drop a few drops of ARO, and try again. It should get easier. Reinstall glow plug, leaving it loose one turn, install igniter, and attempt to start. It should start, remove igniter, and tighten the glow plug.

After a run of a tank, it should be easier to crank. When storing for the night, use ARO in engine. If the pinch is excessive when cold, loosen glow plug one turn. Follow procedure stated above. After time the pinch wont be so excessive. Part of breaking-in proccess.

Try that! It come easier!!! Have fun!!!
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Old 07-05-2008, 02:06 AM   #11
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Hmmm you say you had a plug blow is there any scoring on the side of the pistion maybe? or damage to the top of the pistion? - the pistion getting tight at TDC is normal on most motors as the bore is tapered towards the top normally (you have not said what motor it is) on race motors.
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Old 07-07-2008, 09:08 AM   #12
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Hi, I m pretty new to this but what if it has something to do with your shims? Maybe you are missing shims or a shim is damaged. Also, is your piston detonating? - Is the piston head black?
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