Blew a spark plug out

[lon]

Anyone ever blow a plug out of their cylinder head before.

[nastynotchback1]

I have seen them blow out when they were left loose and then they slowly worked out untill they got blew out.If it was on your a/c motor i may have another head if you need it.You can have it.

[lon]

It was for the a/c. I thought I had it tight but who knows.I moved the timing and that made it run a lot better,I think with the wider belt I need to drop the roller weight a little bit I'm at 3.75 now gonna try 3.5. Thanks for the offer nasty,I already have one on the way. If I pop this one I'll hit you up.

[Thumpin440ex]

Never on a bike, but have seen it a ton on car engines.

John

[bloodswet&gears]

Had this happen due to we were using thread reach H on ngk plugs which is only 1/2. went to E thread reach(3/4 long) and no problems since. I messed the threads up tightening the chit out of'em with the short plugs. Went to the gate, started it up. He cleared it out and the plug blew out. Did fine all day and blew out in the main. There is a lot of info on here about those plugs and some people talk about using 2 gaskets with them.

[Ryko racing]

Had this happen due to we were using thread reach H on ngk plugs which is only 1/2. went to E thread reach(3/4 long) and no problems since. I messed the threads up tightening the chit out of'em with the short plugs. Went to the gate, started it up. He cleared it out and the plug blew out. Did fine all day and blew out in the main. There is a lot of info on here about those plugs and some people talk about using 2 gaskets with them.

On steel head put a little blue Loctite on the threads. We had an issue on our 120 cc race snowmobiles and that cured it. Plus blue is removable.

[LT80]

I had one blow out on my 250R once.
PPl use 2 washers on a plug to aim the open side of the electrode (or at least that's why I did it).

[lon]

When I moved the timing I let my daughter do the test runs with the fan off, do you think that would cause the head to get to hot.