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Konakev
03-30-2020, 06:32 PM
I have here a picture of one spark plug I pulled out. This is the worst one out of the bunch but they are all generally in the same condition. A little oily around the threads and a little carbon built up. The electrodes are still present ... Is this normal for a motor with 800hrs? Or is this indicative of a more serious issue (I:E top end needing rebuild or needing valve job)? And what spark plugs are you guys running? Boat stays between 2000 feet to 6000 feet (if it matters)https://uploads.tapatalk-cdn.com/20200330/e960db868c3584263932ae1253af2086.jpghttps://uploads.tapatalk-cdn.com/20200330/b6ba47e75715eca0057aaf5020e5fb23.jpg

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michael hunter
03-31-2020, 06:44 AM
What year and engine do you have?
Thor
03-31-2020, 06:48 AM
To be safe, check your compression on all cylinders.
MJHKnox
03-31-2020, 09:11 AM
Call SKIDIM with your year and motor size. I think I noticed this yesterday on Facebook, 454 correct?
angus2112
03-31-2020, 01:09 PM
run a r45ts ac delco or if you want to spend more money mr45ts
are you running points any coil up grade ?
buy the looks getting the right plugs will clear up your carbon issue
Konakev
03-31-2020, 01:38 PM
What year and engine do you have?1990 454 pcm

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Konakev
03-31-2020, 01:39 PM
run a r45ts ac delco or if you want to spend more money mr45ts
are you running points any coil up grade ?
buy the looks getting the right plugs will clear up your carbon issueYes msd ignition, blaster ect. https://uploads.tapatalk-cdn.com/20200331/34e14824afb1adf6d3266fe31947eb03.jpg

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Konakev
03-31-2020, 01:40 PM
Call SKIDIM with your year and motor size. I think I noticed this yesterday on Facebook, 454 correct?Yes on the supra page.

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michael hunter
04-01-2020, 07:57 AM
Not a fan of MSD ignition definitely not a fan of the butt connectors on the red and black wires. The correct plug is a AC MR43T. The MR45T will run a little hotter.
Konakev
04-01-2020, 11:26 AM
Not a fan of MSD ignition definitely not a fan of the butt connectors on the red and black wires. The correct plug is a AC MR43T. The MR45T will run a little hotter.I agree , previous owner installed MSD. And did the connectors. I'm contemplating buying a new motor or even crate motor or trying figure out pricing for a new rebuild. (Change to roller cams and new top end) but want to ensure the pistons and bottom end are good before I do all that.

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michael hunter
04-02-2020, 08:39 AM
That engine only has 800 hours its not even close to worn out. What problems are you having with it?
Konakev
04-02-2020, 09:26 AM
That engine only has 800 hours its not even close to worn out. What problems are you having with it?No real problems. Just runs a little warm (around 180-200 ) but i know I have the wrong thermostat (180*) degree need to change out for a 160*. I just pulled plugs to inspect overall health of motor. I'll repull the plugs off after running for a couple hrs to verify. Just trying to learn the motor and parts.

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michael hunter
04-03-2020, 08:24 AM
Go with AC spark plugs don't get fancy with some smoke and mirrors brand . Never use Champion in a GM.
docdrs
04-05-2020, 07:16 PM
It would be nice to know how long these plugs have been in the motor. Are they the original? I think I will replace my 11 year old plugs this spring. The engine still runs strong, like the day I bought it. No misfires, starts right up , I will post pictures of my 11 year old plugs in a week or 2. Yours look like the boat has not been looked after or 20 years old.