Cross Threaded Glow Plug
 

I bought a used plane off of someone from the field. It was idling rough so I decided to put a new glow plug in. It was kind of tough removing the old one. I think it was cross threaded. I took it out and now none of the new glow plugs want to go back in.

Will I need to order a new head or is there something I can do to fix it? I remember seeing at autozone some stuff that you can put on to the tip of a screw and rescrew it back in and it'll make new threads. But, first I dont know if it'll work for what I need. Second I dont know how it will handle the fuel and heat.

Suggestions?

Its an OS .46 FX Max

RE: Cross Threaded Glow Plug
 

You could try to chase it with a tap, make sure you clean the chips out. It may work, or you may not have enough thread left. Either way you would most likely be needing a new head.
But wait and see what others may say.

RE: Cross Threaded Glow Plug
 

You dont know by any chance what the thread size for a .46 glow plug would be, do you?

RE: Cross Threaded Glow Plug
 

No, I don't, never needed that info. Hang tight. Sombody here will offer it. Or call tech support at tower and see if they will tell you what size the glow plugs are.

RE: Cross Threaded Glow Plug
 

The size is 1/4-32 for glow plugs. The easy fix is to have a helicoil fitted in the head. Check out C Lee in RCM or other Add's.

Cheers.

RE: Cross Threaded Glow Plug
 

i dunno if you could get a heli in a motor that small....

RE: Cross Threaded Glow Plug
 

The Ghost is right Clarence Lee has been fixing heads for about 100 years now...Rog

RE: Cross Threaded Glow Plug
 

My dad tapped it for me and it seems to fit fine now. I'm going to run the engine and see if anything leaks or not.

My question is. The previous owner had a short fox glow plug in it. I dont know if he used a short because it wouldnt screw all the way in or not. Why would someone use a short plug as opposed to a standard size?

RE: Cross Threaded Glow Plug
 

You'd use a short glow plug for clearance issues/manufacturer recommendation is all I can think of. Just my .02 cents.

Rich

RE: Cross Threaded Glow Plug
 

That engine requires a standard sized glo plug. If there was short reach plug in there, that would account for the rough idle.

RE: Cross Threaded Glow Plug
 

For future reference, Tower sells a glow plug tap for about $10. Also, there is a store on EBAY that sells parts for engines. Heads, carbs etc really cheap. They even have 20 year old parts for Super Tigre and OS, brand new in the package.

RE: Cross Threaded Glow Plug
 

Most os heads cost about $15 so that shouldn't be a problem if you can find one.