Thread:

Ugly spark plug

Well what do you think?
This is after about three times going out to the lake. All other plugs look fine. Ive done a comression test and it came out just a little low than the others, but within 10lbs of the highest cylinder.
Im running a stock 454 with new dizzy and wires and NGK R YR5 plugs.
Im burning about a 1/2 quart of oil in 3 trips to the lake also. Only thing I can note as far as changes was I added a dual plane mid rise performer intake. Im pretty sure that the gaskets are in ok but I am not sure as if the gasket matched up or not. (im not sure why I skipped that)
Im wondering what I should do. This is my only motor that I have right now and its running fine. I dont want to miss out on the season but dont want to be stupid either and cause further harm.
Ive got it narrowed down to leaking intake, Mis matched gasket, valve seat worn, maybe bad rings. Any help would be greatly appreciated. I trust the knowledge here than any local shop that I have around.

Ive owned the boat for 3 seasons now and it was burning fine. I added intake last season and at the end of the season I noticed it burning oil and a fouled plug. Replaced the plugs at the start of the season and now I am here. I never had an oil issue before the intake but also never drove it as hard as when I got the intake and diverter on.
Forgot to mention that its #8 cylinder. Whats my next course of action?

If it started after you added the new intake, thats where I would start to look. there is a possibility that the intake gasket did not seat correctley, maybe some crud under it, and oil from the lifter valley is getting sucked into the intake causing the plug to foul.

If the boat did not burn any oil and did not foul plugs before the intake swap, thats where I would start. It is cheap, and shouldnt take you all that long.

I would check the valve seal after that.

Ryan

I wonder if its a valve guide since it is not working its way to far into the plug.