Seized Piston

If you do go that way, you can now buy just the engine without the kit parts and use your old kit parts.
 
He is in texas and probably working his butt off on the job. Send him a private message the man is good about helping us less mechanically inclined.
 
What have you found out so far? Are you ready to put it back together?

Re-installing the piston/ring isn't that hard. Lots of light oil and some deft fingers and it will go right in. Or....you can buy a cheapo piston ring compressor from J.C. Whitney or rent one from the local auto parts store.

Just tip the piston on the wristpin bearing a little and start it into the cylinder.

Piece of cake.
 
Bikeguy Joe said:
What have you found out so far? Are you ready to put it back together?

Re-installing the piston/ring isn't that hard. Lots of light oil and some deft fingers and it will go right in. Or....you can buy a cheapo piston ring compressor from J.C. Whitney or rent one from the local auto parts store.

Just tip the piston on the wristpin bearing a little and start it into the cylinder.

Piece of cake.
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The little thing he left out is what got both my rings broke... You have to find the little nipple inside the ring groove and make sure the opening in the ring is round it. otherwise that little nipple will break the ring. If you run your finger around the groove you will find the nipple and can position your ring correctly. Mine went in easy after that and no damage. didn't need a compressor just worked it in by hand.

Sorry I don't have any pictures of if but there are some pics somewhere I have seen them before. That little nipple thing is why I said to be sure to ask before you try to put the piston back if you haven't done it before. Otherwise it really is simple.
 
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I have some pictures, I will post when I get time. My 50cc siezed up on me two times. If you pull the jug, check the lower edges of the ports, sometimes they are not smooth and the rings can catch. If it's siezing, I would not ride it. If you have debris in the engine it will score the cylinder and could cause damage in the base.
 
deacon said:
The little thing he left out is what got both my rings broke... You have to find the little nipple inside the ring groove and make sure the opening in the ring is round it. otherwise that little nipple will break the ring. If you run your finger around the groove you will find the nipple and can position your ring correctly. Mine went in easy after that and no damage. didn't need a compressor just worked it in by hand.

Sorry I don't have any pictures of if but there are some pics somewhere I have seen them before. That little nipple thing is why I said to be sure to ask before you try to put the piston back if you haven't done it before. Otherwise it really is simple.
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My bad, I figured that was a given...the ring won't go on the piston if you don't line that up, so I didn't figure he'd try to put the piston in the jug with the ring sticking way out on one side.rotfl
 
It's also a really good idea to check/adjust the end gap of the new ring(s) before installation too.

Did Norman tell you to do that?
 
Well I'm the guy who didn't know that and broke both rings before anyone told me there was a pimple on the pistons butt lol... No i didnt adust anything just stuck them in there. when i tried to compress them is when I found out as they snapped off in my hand.

That wasn't a criticism. It was just a point that us non mechanic types don't know. I figure if I didn't know no sense taking a chance that anyone else doesn't.

HOpe I didn't step on your toes.
 
bgoates said:
the needle clip is 2nd from top. fuel mix 25:1 with snowmobile oil. I put a new plug in yesterday and after 10 minutes it was black. Should I try mixing 30:1 ? Move needle to top clip ? Mix pee with it ? Or what ?
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I'm no expert, but isn't snowmobile oil supposed to be more sooty/ashy or something? I would try using a different oil.
 
I doubt running a generic "snowmobile oil" will cause a problem. (technically there is no such thing other than what the label reads)
 
Well I think I got it fixed. My carb has been leaking fuel like crazy so I finally got around to taking it off and adjusting it correctly. I noticed the air filter was soaked with fuel so I figured that it must have been choking the airflow. So I removed it and but the carb back on and went for a long (almost full tank) ride with no problems. Engine ran the best ever. I will put the air filter back in tomorrow now that I got the flooding problem fixed. I am learning a lot and hopefully the problems will be fewer. Thanks everybody for your support.(^)
 
Exellent!

deacon- did I seem terse in my reponse? Sorry if I did. Sometimes I forget that everybody hasn't been working on i.c. engines since they were knee high to junebug and I assume stuff.

I saw a guy try to screw on his carb up side down once (on a dirtbike) and when I laughed at him he almost gave me a knuckle sandwich. I just assumed that everybody knew they didn't work that way.
 
Bikeguy Joe said:
Exellent!

deacon- did I seem terse in my reponse? Sorry if I did. Sometimes I forget that everybody hasn't been working on i.c. engines since they were knee high to junebug and I assume stuff.

I saw a guy try to screw on his carb up side down once (on a dirtbike) and when I laughed at him he almost gave me a knuckle sandwich. I just assumed that everybody knew they didn't work that way.
Click to expand...

Well I just didn't want to offend you. Your advice is always right on, sometimes I tend to think everyone is as dumb as me lol. Honest I had no idea there was a bump in the ring groove. I worked on a lot of cars but this is my first time inside any engine at all. If my engines needed that kind of work I took them to the shop. This has been a really good experience for me.

On this engine we are talking about here, it occured to me that it might be overheating. I had a pinto seize for that, but it never did work again. I'm glad his freed up with apparently no harm done. Its the old timex big ben and the swiss watch thing. These cheap engines will take a lot of abuse evidently.
 
Look at my top end take apart and rebuild for some info on putting the piston back into the cylinder and the way the rings fit on the piston around the ring pins etc. the wooden piston support stand will really make putting the piston in the cylinder very easy and you will not have to fight it as much. the wooden tool can be made out of a wood shingle or wood stirring stick even a couple of popsicle sticks will work in a pinch and you can run down to the min mart and get your favorite flavor eat it then use the sticks.:D
Norman
Look up 2 stroke engines on Google there is a lot of info on piston and cylinder clearances etc and why a 2 stroke will seize. these engines run with some very close clearances compared to 4 strokes. warming up a 2 stroke before putting it under a load will stop a lot of seizures.
 
How many hours of the engine? Almost sound like the the piston clearance is too tight. Check side wall of cylinder on the exhaust side for scoring. Scorring is normally due to a cheap oil/overheat situation. As far as the black cylinder, I have never seen anything like that before, when you pull the jug off all should be shinny except piston top and head, maybe a bit of slight darkning of the exhaust side. Let us know. Curious now !
 
Here is a picture of the top of my head, and pistion. It's black too.

ibj221.jpg


286r9ye.jpg


Runs good like that. What are the walls of your cylinder like? Run your fingers accross it.
cylinder walls are shiny though.
 
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Looks like you head gasket was leaking. Time for a de-carbon too. Use a wooden stick.

24:1 or 30:1 synthetic oil after will keep that to a minimum.

Piston skirt scuffing is usually from "cold seizure" where the piston expands faster than the cylinder walls because of too much load/revs too soon before the engine is fully warmed.
 
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