spark plug cross thread????
 

I did a compression test today. The leading plug on the front rotor was alittle harder to get out than the rear one, I didnt think much of it. But when i went to put it back in, i had trouble. It will go straight in for a turn or two then it goes at a weird angle and is harder to turn. I didnt crank it in because i was scared to cross thread it. Is it possible the previous owner cross threaded it for me? :( What do i do???

wow in a situation like that if it is 100% cross threaded you have to get a tap and re tap the whole and hopefully catch the threads again... id like a rotary mechanic do that if you dont tap is str8 youll fuck up the housing....
TwEaK

I wouldn't want to tap it and risk getting any shavings in the engine....

If you can thread it into the housing as far as it's supposed to normally go, then go ahead and do it, even if it's already crossthreaded. There's not much you can do about it now.

Use copper, zinc, or nickel based anti-seize compound on the threads before installing the plugs...

crap, so now i have to pull the engine (no lift or garage for that matter) and either tap it or buy a new housing... im so screwed :tear:

The rear leading plug in my cosmo re is cross threaded. I just got a thread chaser and made the 'new' threads as good as i could, and take my time changing the plug. Sucks, but its the only thing short of pulling the motor icould think of

-Jacob

How did you keep metal shavings from going through?

No, like I said, even though it's cross threaded, if it still sits correctly in the housing (check the distances between the housing lip and plugs in the "good" and "bad" positions) and torques down well enough to not allow any movement, go ahead and use it...

BTW, you said you were doing a compression check- how did the adapter thread into the bore? Did it feel like it was cross threading too?

It screwed in just enough to do the check, It was hard to get it to work though... the plug goes in some but then goes at a angle

You can bite the bullet and tap/ clean the threads if you want (I'm not going to stop ya, lol), but I wouldn't do it. But that's me. I'm the paranoid type :)

If you're using new plugs, and you can get the one in far enough to crush the washer, then she's good...

If it works, don't F#$% with it. Use anti-seize...

when it starts at an angle and gives alot of resistance it isnt even close to crushing the washer

the last owner didnt cross thread it...
YOU did...

if the last owner did, and he screwed it all the way in, you would have a hard time unscrewing the damn thing and that hting would get damn hot.

Maybe, maybe not. We are talking about aluminum here, a very soft alloy...

That's gonna be the problem with tapping it, too...You might actually displace the metal instead of cleaning up the threads...

Monkey, do you have a torque wrench? Foot pounds, preferably...

actaully it was harder to get out than the other plug, i thought it had seized in there or something. No i dont have a torque wrench, I am living in an apartment with basically no tools. :( I had to borrow the spark plug socket and the compression tester lol

It's your call, man...

Normaly the shavings or debry will just go right out the exhaust. You do have a chance of wiping out a apex seal or above tolerance damage to housing. Be sure to back the tap out and clean it evry 1/4th turn or so. When teams build race motors all of the holes are drilled out and heli coild. To prevent this exsact problem and for greater hold. But that requires the motor torn down.

I would tap. But its your call.

If it was hard to unscrew for more then 2 turns then it was allready cross threaded. Or it was just harder and you relayd it to this, you may have done it with the compression tester, they are hard to screw in straight with the hose swivaling around and all.