I had a concern when I was starting the engine Memorial day. It ran good all weekend then Monday it started and idled for a few seconds and died. That seems normal for being cold but then went to restart and it had a banging and broken sound when cranking. I don't know how else to explain it and if I could I might know what the problem was. I tried to start a few more times to listen to the noise so I can figure it out then it went away and ran fine. I ran all day without anymore problems. Not sure if that is related to the #1 cylinder but I don't know what it was. Maybe even kick back on the starter.

Here is a pic of my plugs. I did notice last year the #1 had some oil on the plug but the noises had me concerned to investigate further now. Can someone give me some ideas here? I did a compression check at the end of last season and they were all good but I will do another tonight and post of the results. I had a chance to leak down the cylinder last night and its at 11.25%. I will leak down the others and post that as well. At 11% I sure am getting a lot of oil in the cylinder. Would this be a ring issue?

Can I run it for the season and just keep replacing plugs and rebuild in the winter?

I have had to run anti-fouling spark plug sleeves before. They set the plug back so it doesn't get splashed with oil. I got it at autozone if I remember correctly and it worked to get me through to winter.

One easy thing to do would be to pull a valve cover and check the valve train for that cyl. Once I broke a rocker arm and the engine ran rough until the rocker moved a little and wedged itself into the spring and held the valve open just a bit. Then it was backfiring and clanking.

Well now I am more confused. I re-did #1 leak down and got a different number. Here are the results so far. Leak downs look like crap and #1 is not even the worst but one of the best. This was all done cold.

cyl - comp psi - leak %
1 - 127 - 18.75
8 - 118 - 20
4 - 115 - 52.5
3 - 125 - 16.25
6 - 115 - 26.25
5 - 120 - 20
7 - 127 - 13.75
2 - 115 - 40

As for the banging I am thinking starter issues if possible. While I was cranking for compression check it sounded real rough.

As for the anti-foul adapter I have one so I will try this. Should I do all cylinders though?

Also I pulled valve cover and started to check valves since the worst leaks are in the exhaust and I only checked #1 so far and have .022 of clearance. I thought I have a hydraulic cam so this doesn't make sense. How can I check to see what lifter type I have without pulling things apart?

what hp engine? efi, blower ? If you push on the end of the rocker arm (push rod side) and if you can push the lifter in about .100 thou then its a hyd cam..if theirs no movement then its a solid..

from a car stand point when i see a spark that black and the vehicle has a miss its because theirs no fuel getting in the cylinder and the engine trys to run on the compressed air and oil left in the cylinder..if you have efi and it has a injector per each cylinder make xure they are all working..

Thanks for the reply. This is a 509 or 540 originally built by teague then someone rebuilt after. Mega 420 blower, 2 4150 750 cfm, superchiller so about 850hp. I do have the parts list originally put in and pretty sure it was hyd. I did try to push and it didn't even move.

that would explain the lower compression..supercharged!

the rest of the plugs look lien..also the r43ts plugs seem to be the wrong plugs,,most blower motors will run a colder spark plug like the 800 sc i believe is a mr41t? i would check the engine more thural for possible piston or valve damage..

clean the goo off the #1 plug and make sure theirs a gap their,cant tell from the pic but someone could have dropped it and stuck it in with out rechecking the gap..that would give you a dead cylinder.

interesting you say too hot. the one I took out last year from previous owner was a r44ts so even hotter. I looked into that last year and decided to run the 43 based on a few things. I think I cross referenced and came up with that. It is also listed here as the colder supercharged plug. http://www.cpperformance.com/p-13771...x-tapered.aspx
where do you get the mr41 spec for merc. I looked at NGK and can't cross reference. I will get colder ones to replace then.

As for clean the goo, I put those in last year so I know there was a gap. It is kind of still there. Even the r44 I took out from before looked gummed up. I also replaced the coil, wires, cap and rotor to help this problem. I will check all the valve lash tomorrow. There must be a solid cam now.

That is very interesting. Makes sense.

Well I pulled both valve covers and checked valve lash. Here is what I got

cyl - exh - int
1 - .023 - .023
8 - .022 - .023
4 - .023 - .024
3 - .026 - .025
5 - .025 - .024
7 - .023 - .025
2 - .024 - .024

So looks like its a solid roller and I have some serious valve issues. Since they are closing all the way and have a high leak rate maybe I can just get a valve job. I looked in some cylinders to look at the valve edge and they didn't look bad. I think they are inconel so would the head valve seats be most likely the problem?

Still don't understand the fouling on #1 yet.