Engine Trouble engine seized (piston locked to head)

[mastacalus]

Hello I am fairly new to 2 stroke engines, but this is my second motor. The first 1 ran for about a month until I had it screaming at 52 miles per hour and melted the piston to the side of the head... So I bought a new one. I just got it installed last night and took it for about 4 small runs. It ran great...

This morning I got up to go to work and I went to start it it made about 3 revolutions and then the back tire seized up.

It felt exactly like when the piston seized to the head and melted itself in... considering that the bike had not even started yet I knew this was impossible. So I took the spark plug out and pulled the top of the head off Then went to remove the head and the piston moves with it. Try to softly tap on it with a rubber mallet, no go. I know I'm going to be able to get the piston off of the side of the head but I'm wondering what I am doing wrong? And what might be the ea.siest way to actually get the piston off of the head without causing any damage? I bought the motor from livefastmotors.com, not sure if anyone has had an issue like this

 

[BigBlue]

52 mph, your going to burn your engine up every time, especially if your going downhill - not enough lubrication.

What is your oil/fuel mixture and type of oil? Make sure the mixture is well mixed.

Good Luck,

Chris
AKA: BigBlue

 

[mastacalus]

The 52 mph was more of a 1 time thing than anything else, I just wanted to see what it was capable of. Now this is a new motor that I bought and installed, no problems, but this motor hasn't even gone above 20 mph yet.

Now, onto answering your question. I'm using what I was told for breakin, which is 32:1, maybe I have it backwards? But either way, I'm wondering if it even had enough time to do any real damage. The type of oil Im using is a very cheap brand I think - "Itasca 2-Cycle Engine Oil."

Consider this, and tell me if I'm off a bit - The engine ran very nice 4x, sounded great, the whole shabang. This morning it was a bit cool, so I guess since the piston could've been cold just a hair smaller to where the piston could've cocked a little to the side and just enough room to catch on the piston ring or something? Does this happen often? If it does is there a way to try and prevent it from happening again? Thank you for help in this matter.

 

[grinningremlin]

If you have $$ for spare engines you're good, otherwise look at it like a car, just because it can doesn't mean you should.Personally from all I've read here I don't think china-girls are for beating, unless they're seriously modded and well maintained, they're fraught with slop.Go with a quality jap motor set up, costs more to begin with, but you won't be on your second engine any time soon.

 

[swamprat]

what did you do to get 52 out of it. they don't normaly go that fast. when you say the piston is stuck to the head are you sure that you don't mean cylinder. the piston is not supposed to touch the head?
if you take the head off you will see the top of the piston in the cylinder.

 

[mastacalus]

If you re-read my thread, the new motor is the one with the piston jammed, I started it up after install, ran it gently around the block 4 times, and pit it up for the night, woke up to ride it, and upong releasing the clutch to start it, the piston jammed in the cylinder. The motor that did high speeds is toast and not on the bike.I just want to know if anyone else has had these problems and of so, how did you fix it?

 

[crassius]

from your post, it sounds like the piston is stuck in the barrel rather than the head - if this is the case, then remove the studs (by double nutting) so you can twist it a bit to free a broken ring from the ports

 

[relaxxx]

If it was mine I'd probably try to budge the piston with the spark plug removed. Spray lots of lubricant inside, let it soak, heat gun or torch the head/cylinder to 350F or so, find a steep hill and try to turn it...

 

[mastacalus]

I thought about removing the head studs as well. That's what I think I'm going to try first, I just thought I'd ask to see if there was anyone who had this same issue and achieved their desired result. Thanks everyone, more replies are welcome of course.

 

[V 35]

The 3 revolutions bothers me, if the fuel was left on, the carb overfloated, the cylinder hydro locked, than it wouldn't budge, right ?
Since it spun a few times, I'd check the clutch / small bevel gear . I could of sworn my Skyhawk seized, but it was just a broken, and jammed bevel gear. Good luck. As for 2 stroke lube, the golden rule is ... Add Extra Oil for Break in. I like to short the gas, if it calls for a gallon, I put in 3 quarts, resulting in an oil rich mix.