yellowdog5
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- 1979
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How often should I replace spark plugs? 79 size 400 motor
Elementary question, spark plugs.
- Thread starter yellowdog5
- Start date
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fast 99
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Really depends on condition of motor. 400 has a tendency to use oil because of the cylinder walls. I would check every 15k or 1 year and go from there.
Rusty Nail
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I vote the OE spec calls for 30k intervals - 10 oil changes.
Grit dog
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When one starts missing.
GTX63
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Assuming your 400 is in good condition, and the plugs aren't oil or gas fouling, check the tip/electrode for wearing or rounding.
Ultimately, buy a replacement set now, and your engine will tell you when it is time.
Ultimately, buy a replacement set now, and your engine will tell you when it is time.
