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Old 09-22-2022, 07:17 PM
  #21  
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Originally Posted by SB View Post
Looking thru my phone my eyes went to cyl #6 for now.
Appears to me like many pepper marks.

Detonation shows up on the plugs as spotting on the porcelain. There are two different types of spotting seen. One type appears as just black spots and the other appears as little bright spots like diamonds. The black spots (look like pepper sprinkled on the plug) indicate a little too much heat on the plug which causes detonation by having the heated plug fire off the mixture prior to the spark firing. This creates two flame fronts that collide and can cause great amounts of damage. If you see black spots on the porcelain and you know the tune-up is correct then you may need a colder plug. If you are not sure then increase the carburetor jet size slightly, take out some timing, or go to a colder plug. If you hold the plug in the sun and you see what appears to be small diamonds on the porcelain then your detonation is severe enough to be blowing off the aluminum from your piston and you need to add fuel and/or take out timing now.
I just got a look with little better video screen at #6 plug and its really concerning.

8 7
6 5
4 3
2 1
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Old 09-22-2022, 11:22 PM
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Originally Posted by boostbros View Post
those 2 black plugs are something wrong wires not on correct cyl? cam firing order swap? black and wet is not firing
I've been trying to get the shop to get me in to check the timing and plugs for 3 weeks. I guess the motor left the shop and they're done with me. I'm going to give him another chance to respond tomorrow before I just cut my losses and go to another shop. Still haven't received the build sheet and I picked up the boat over a month ago.

I checked wires before my last outing and #2 almost didn't feel like it was on good. I was hoping for an improvement, but no change. I will verify the firing order again to rule that out. The boat feels down on power from what I would expect and the timing is all out of whack. You'd think this place would want to get me in. I even told them I'd pay labor if everything checked out. For F*CKS sake.

You don't think it's firing at all on those two cylinders?
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Old 09-22-2022, 11:34 PM
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Originally Posted by boostbros View Post
those 2 black plugs are something wrong wires not on correct cyl? cam firing order swap? black and wet is not firing
Originally Posted by ThisIsLivin View Post
How old is the balancer? They set the timing before doing any hard dyno runs and the ring could have slipped and now reads 40. Get a piston stop and check your timing mark. 3924 is recommended by AFR for Pump Gas, I run them in my motor and they are not too hot based on the ring on the electrode. But my motor runs super cool anyway. You definitely have some distribution issues. Even bank looks a little rich across the board with 4 and 7 really fat. I would try a 1" tapered spacer with a 1" open to try and get better distribution. When I pull my plugs you can't tell one from the other and I'm running a custom 1000CFM 4150 on a Brodix HV2000 intake with both spacers I mentioned.
They reused the balancer, so it's probably got some hours on it. I had a really nice Holley marine 1050 on it and he said somoene had drilled on it and he couldn't jet it enough, so he ended up putting on some old BG 1050. I wish he would've called me because I would have picked up a pro systems or a new one, this thing looks janky.

I may actually have an old HVH super sucker I ran on my car years back. I'll see if I can dig it up and give that a try.

BTW I have the plugs facing like you're looking at the engine, so it's the odd bank and #2 and #5. Not that it really matters, issues at the end of the day.
8 7
6 5
4 3
2 1

Appreciate all the advice man!

Last edited by 540Fever; 09-22-2022 at 11:45 PM.
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Old 09-22-2022, 11:38 PM
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Originally Posted by SB View Post
I just got a look with little better video screen at #6 plug and its really concerning.

8 7
6 5
4 3
2 1
#2 and #5 are fat and according to what you're seeing, #6 is either lean or detonation?

Amazing this thing was apparently dyno tuned too.
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Old 09-23-2022, 07:19 AM
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Detonation.

Here is your #6 close up.



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Old 09-23-2022, 07:37 AM
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Originally Posted by SB View Post
Detonation.

Here is your #6 close up.


Thank you. Based off your precious post its the actual porcelain youre concerned with? I see the peppering youre talking about.

does the ground electrode show anything that would also mimic detonation?
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Old 09-23-2022, 08:02 AM
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Glazing on porcelain shows rich at idle.
Black specs show detonation typically from too hot plugs and/or timing.
More detonation would show up as tiny aluminum balls down towards bottom of porcelain. You need a good kight snd sometimes magnifying glass to see it.

Id set total timing to 34.
Id run a colder plug. The autolite 3923 or ngk bkr6e. Maybe even bkr7e for now to play it safe ? Gap any of these to .035.

btw: slightly off topic, but since it will be effected when you change total timing, what is your initial timing ?
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Old 09-23-2022, 08:54 AM
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Go to Walmart and get yourself an Otoscope in the pharmacy department for checking your plugs. Best money I ever spent. If you had 2 cylinders not firing you would have a hard time getting on plane and it would shake something terrible. What ignition are you running and what wires? Check the jets on the carb to see if they are the same on both sides as well.
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Old 09-23-2022, 09:10 AM
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Originally Posted by ThisIsLivin View Post
Go to Walmart and get yourself an Otoscope in the pharmacy department for checking your plugs. Best money I ever spent. If you had 2 cylinders not firing you would have a hard time getting on plane and it would shake something terrible. What ignition are you running and what wires? Check the jets on the carb to see if they are the same on both sides as well.
This is a DUI7000, new MSD wires were installed as well. Not sure on the jets since I still haven't received the build sheet.

Shop just text me back and said: "if the plugs look like this after normal boating then they're fine. It's a carburetor with a big plenum."
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Old 09-23-2022, 09:37 AM
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I find a spark plug magnifier is a great tool to see the plug but I still don`t know what I`m looking at .
I thought the ground strap tells the timing story ...



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