|
That first thread looks slightly stripped. If it jumped a groove, then each time it turned as it was being spun in last time probably regrooved the head threads.
If this was a car, I would say just get a long-life spark plug and thread that sucker in there as best you can and live with it... but this is not a car.
This isn't the end of the world though. Try cleaning it as much as you can first. It may be a piece of debris that's not allowing the new plug to go in. It could also just be rust. That plug looks worn, like what I would expect to see coming out of a lawnmower.
Some people will advise against this, but a single pass with a wire brush can't do much harm. After that, vacuum out the port hole and try again. A little spark plug thread grease can't hurt either.
If the threading isn't really all that bad, just keep trying to thread your new plug a slightly different angles. At some point, it may catch the original groove and you'll be good to go.
|