Saito 100-Glow Plug Blew Out of Head
 

Was tuning on my Saito 100 after it would not idle. I had put a Fox Miracle Plug in it and it would not idle unless you left the glow igniter on. Went and bought an OS Type F and bingo it idled fine. I was setting the high speed needle, had leaned it out to max rpm backed off 200 rpm and was pulling it back to idle and POW something poped. Took the cowl off to find the glow plug missing. Looked around and found the glow plug. When you tried to ignite it, it was shorted out and just got hot but did not glow red. The threads in the head seem OK. What is up with this?
Lee Mitchell

RE: Saito 100-Glow Plug Blew Out of Head
 

That happens from time to time when the glow plug vibrates out. You don't want to overtighten the plug because you can strip out the aluminum threads in the head. Can't explain why the glow plug got ruined in the process. Running too lean / too hot will damage a plug, but the act of flying out should not have hurt it. ANyway, just get another one and try again. You want to tighten it enough so that it doesn't come loose but not so much to strip it.

RE: Saito 100-Glow Plug Blew Out of Head
 

Wow! Either the threads in the head don't match the plug threads, you put the plug in with only the first thread or two engaged or you may have overtightned the plug and the threads were seriously weakened. I would be interested to see the feedback that follows.

Bill

RE: Saito 100-Glow Plug Blew Out of Head
 

I recently had a plug blow out like that on a BGX engine. Was trying to tune it & it would'nt take more than about 1/3 throttle when it just popped like a firecracker. I have this engine mounted sideways & I was standing about 1 foot behind the engine so that plug almost caught my leg. I got this engine used from a friend & I don't think I ever checked to see if the plug was in tight. Had to have been loose cause I've since replaced the plug making sure it's in tight & no problems. Did'nt damage the threads & I never found the plug.:D

RE: Saito 100-Glow Plug Blew Out of Head
 

bummer i hope that head is not stripped

RE: Saito 100-Glow Plug Blew Out of Head
 

I had this happen on a Magnum and my wrench had bound up on the head beside the plug and the plug itself was not originally tight

Never did find the plug but it didn't hurt the head

RE: Saito 100-Glow Plug Blew Out of Head
 

Happens when you use the headlock type glow plug driver like the mcdaniels and turn anticlockwise to attach and lock or loosen and unlock.The glow plug will eventually work its way loose if you use force without knowing.