Sticking it

Only irregularity i can see is that the very top edge of the cylinder is somewhat roughed up and the rubber o-ring is mangled up...it would appear that maybe some small fragments of material may have been bouncing around in the combustion chamber as there are some small dings on the top of the piston and around the head where the spark plug is....if that o-ring came out of the groove it sits in, surely that would cause a loss of compression, hence maybe why it wouldnt start?
 
pull the head and take the cylinder off. i am 99.9% positive the intake side of the piston has a broken skirt. seen it tons of times on the cast IAME pistons.
 
With the head off is the piston going too rock a bunch ?
Or will the peice be trapped somewhere .
Not doubting your expertise .
The Op said the cylinder looked pretty good .
Most times when i have had piston issues the cylinder was tore up .
 
Sounds like a good use for an inspection camera .
Look through the exhaust to the other side .

On another thought is the broken piece getting spit out the exhaust ?
 
flattop1 said:
With the head off is the piston going too rock a bunch ?
Or will the peice be trapped somewhere .
Not doubting your expertise .
The Op said the cylinder looked pretty good .
Most times when i have had piston issues the cylinder was tore up .
Click to expand...
Take the cylinder off , that makes sense .
what would max piston clearance be on one of these?
 
If that's the case damage to piston skirt can happens when you have too much play in piston, too much clearance between piston and cylinder wall, for example because you have too many hours on piston.
 
Do you have a vent tube on tank....wet plug would indicate that you did not stick the engine. If you can't get a new plug then you are wasting everyones time here. A new coil isn't as easy to get as a spark plug so you better start with the plug first. And don't worry about fuel coming out of plug hole....not going to happen. Test spark by turning engine over. If you have spark then it is going too be something easy. If you had a crank case seal leak the engine would run at a high rpm and would not want to turn off. Sometimes even going to max rpm before they stick on the stand!!
Get a new plug and go from there. The Sudam is on of the easiest engines in the world to get running.
 
Hoppy sorry if im "wasting your time on here"...this is my first year running 2cycles, im just trying to learn as i go.....and im learning quickly that finding correct spark plugs is difficult to say the least...such is why i dont have spares right now....unless you can direct me to someone/somewhere that has them and is willing to part with them....🤠
 
The sequence of things I checked when things weren't going right.
1. Check the spark plug. Assess it's condition, rich, lean, whatever.
1 a. Check if there's spark.
1 b. Check for fuel flow.
1 c. Pull the back off the carburetor. Assess all the parts.
2. Check the compression.
3. Pull the head. (Carefully assess if it's leaking, if there's detonation, if there's any evidence of something getting loose and causing damage.)
4. Pull the barrel. (Assess for piston damage, base gasket leakage.)
Remember the old adage; "if there's compression, and fuel, and spark, (at the right time) it pretty much has to run." Air leaks can be a problem, but only a huge air leak can keep an engine from running. In
 
Ok guys, finally had time to pull the motor apart today.... and yes...it stuck it....cylinder wall is scored in same spot that that piston rings are stuck in the groove and completely worn down in that spot...will need new piston, rings and cylinder wall cleaned up.... thanks again for everyone's help and insights 🙂....and after thinking about it for a while, I'm pretty sure I now know why it happened.....:rolleyes:
 
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anyone familiar with a process ive been enlightened to today....hopefully I have it correct...."nickel treating cylinder walls"...a way to further harden cylinder walls as to try to help avoid damage to it when piston/rings stick in a 2 cycle engine? costly?
 
An alternative to nikasil plating is a anti friction metal treatment. I started using Pro Tec anti friction metal treatment back in the 80`s
and since then I have never stuck my engines even when my old style KT hit 500 degrees one time (not a misprint and no damage).
Racing hard, not paying attention to gauge and yes I was inadvertently too lean. I never start my engines unless its mixed in my fuel.
 
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