HELP! My plug keeps closing up!!

crazee

New Member
Sep 19, 2008
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I 'm at the break in period with the 2 stroke (China built?) About 50 miles or so on the engine and last night I was trying to get home and the engine bogged down and died. Checked everything out today and the plug was not only fouled but was also CLOSED UP!! I cleaned it up and tried to run it again and the plug closes up almost immediately...Whats going on??
 

misteright1_99

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Mar 21, 2008
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Treasure Coast, Florida
Sounds like it is hitting the piston if it is closing up the gap, although I have seen a post where on the stock spark plug the center electrode is loose and falls down to close the gap. I would try another spark plug like a Champion or NGK......

Looks like the plugs with the black ink are the defective ones according to the post..........
 

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Dave31

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Mar 1, 2008
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Aztlán, Arizona
Welcome crazee to the forum :)

I would have to agree with misteright

If you say it closes up immediately it is most likely is the piston hitting the plug.

You could pull the head off and inspect the top of the piston, if that is what it is you will see signs of it on top of the piston.
 

mralaska

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Aug 16, 2008
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Deerfield, NH
Another possibility is the electrode is loose. I have heard the plug that comes stock can lose its grip on the center electrode which then it slides out and makes contact when it gets hot. Have you tried an NGK B6HS or something like that?

EDIT: I see misteright already addressed that possibility. Oops! Pardon my redundancy.
 
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hill climber

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Sep 11, 2008
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paso robles, california
have any of you seen the inside of an ht head? quite a large dome in there, the piston on the other hand has a rather small dome.the piston doesnt even travel to the top of the cylinder. the piston will definately hit the head before it hits the spark plug, unless you have got to long of a plug in it then this could happen.
 

Jemma Hawtrey

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Dec 29, 2007
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Essex, UK
It may be closing up because of too much oil in the mixture and low speeds.... two strokes can get oiled up and this can cause the plug to whisker.. which eventually will create a short between the two and the engine will start to play up..

it might be worth weakening out the oil mix a little to see if that solves the issue.. Other than that replacing the plug would be a fairly cheap option.

I'd be surprised if the plug was being hit by the piston - for a start you would hear that happening.. and much of that would result in chunks of plug causing all sorts of havoc..

Jemma xx
 

Egor

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Jan 30, 2008
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Hurricane Utah
I hate to be the privier of doom but it sounds like there are parts up top that don't belong. I had an engine that went to pieces in a few miles and it was the rollers from the bottom end they got into everything. I hope this is not the case, but if you take the head off you will see if it is. Have fun, Dave
 

crazee

New Member
Sep 19, 2008
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I hate to be the privier of doom but it sounds like there are parts up top that don't belong. I had an engine that went to pieces in a few miles and it was the rollers from the bottom end they got into everything. I hope this is not the case, but if you take the head off you will see if it is. Have fun, Dave
Thanks to everyone for the suggestions. It seems the plug that came with the kit was too long, replaced plug with shorter plug and so far so good...