Never underestimate the little things

[Tim Kurcz]

After cranking compression & leakdown tests, bore scope cylinder and reed inspection, timing check, and several re-jetting exercises, a starting/idling problem with my turbo Johnson was finally resolved. I would have saved several hours work and had more fun if I'd only paid more attention to the "little things" while looking for a bigger problem. Have never seen this in all my years. No external evidence of gas leakage and no carbon traces...just loose! Go figure.

Tim

[88workcar]

Never saw that before, good find!

[David_L6]

Never had that happen with an NGK but I have had a Champion do that.

[Fastjeff57]

What am I not seeing here?

Dopey Jeff

[Tom M]

I had one like that in our race bike with an NGK.
A rare occurrence indeed, your is only the second I've seen.
I check em regularly now.

[Fastjeff57]

Doh! and double Doh! Never seen an electrode go away like that.

Jeff the Half Blind

[hydroplay]

Not sure why you're running R plugs unless its necessary for some of your electronics. The R plugs are more fragile and will fail when overheated.

[Popa Sam]

Usually caused by overtightening of plug. Sometimes by plug not being rated for temp or compression that is being exposed too.

[Tim Kurcz]

Thanks all for your input. The BR9HS was chosen because of successful experience on the race course with OMC & Merc mod engines. The new set installed will be lake tested next weekend. Should there be another failure, another type will be selected. Will conduct research this week just in case.

Tim

[Tim Kurcz]

Not sure why you're running R plugs unless its necessary for some of your electronics. The R plugs are more fragile and will fail when overheated.

Ok Sam,

So much for my history with "R" plugs. It's off to the parts store for some B9HS NGK's. After only an hour's time on the water today, another BR9HS failed (this time with carbon traces) - along with the head gasket. I'm hoping there is no additional damage: Thankfully the pistons look fine!

Last fall, after about 3 hours total operation, the #2 cylinder fire ring blew on the intake side immediately adjacent to the starboard most head bolt. Replacing the gasket at the river, it was immediately difficult to start, but performed well once lit. It was the #2 plug that had the loose ceramic..........

Today, after about a total of 2 hours operation (less than 1 hour on the new plugs), the #1 cylinder fire ring blew, this time on the exhast side adjacent to the port most stud. Yes, the head was studded after last years breach. The question is: Which failed first?

Unfortunately, this time the head was damaged and will require a .010" cleanup cut. Unless the block is damaged, I will make repairs and secure B9HS plugs this week for a follow up test next weekend. Regardless, This winter the head will be oringed.

Thanks again to all that responded. Images tomorrow night.

Tim