Raptor 400 Spark Plug Tune-up

[parrothd]

Spark Plugs:
Motorcraft SP-526 (16 total)

Remove the Engine cover and side panels.

1. Remove the two bolts for the fuse box and move the fuse box to the center.
2. Remove the spark plug assembly bolts, one per spark plug on the top.
3. Disconnect the spark plus assembly buy pressing on the clip and remove, don't pull on the wires.

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Remove the EGR hose, pull outwards.

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Remove the spark plug assembly, pull straight up, then remove the spark plugs and install new.

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1. Remove the bolts for the ECU/computer, you can gently move this to the center of the engine.
2. This spark plug is partially blocked by the fuel line, disconnect the connector and lower plug wire by pulling on the cap.
3. By moving the fuel line to the side you can remove the spark plug assembly.

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Remove the ECU/Computer mounting plate, 2 alen bolts and one bolt. No need to cut the zip ties just swing the plate out of way towards the outside.


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Remove the spark plugs bolts and assemblies and replace plugs.

Reverse steps to reinstall everything, push the spark plug assemblies into the hole and seat on the spark plug, then rotate to line up.

[parrothd]

Upper spark plus assembly

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Replace the lower spark Plugs 8 plugs as normal

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If you have these metal spark heat shields on the lower wires, they should be removed per indmar, use pliers to pull the rubber insert to remove, don't plug the wire. They slide off.

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[moparsigfan]

Hi,

Do you know the torque spec for re-installing the spark plugs?

Thanks in advance

[parrothd]

Hi,

Do you know the torque spec for re-installing the spark plugs?

Thanks in advance

Nope.. I go with the feel..

[larry_arizona]

Typical torque spec for spark plugs is 18 ft-lbs.


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[larry_arizona]

Don’t over torque a spark plug in an aluminum head.


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[schwan]

I can't get OPs photos to open, tried tapatalk and desktop, is it just me or are the photos gone?

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[parrothd]

I can't get OPs photos to open, tried tapatalk and desktop, is it just me or are the photos gone?

Sent from my SM-G950U using Tapatalk

This is all I have.

https://photos.app.goo.gl/1xaFHurNf8443YDx8

[schwan]

That link worked, thanks!

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[haknslash]

Are new plugs required each year? I looked in the Indmar owner's manual and it doesn't say to replace them each year or to even inspect. On my previous Yamaha boat it was very finicky on spark plugs and it did not run great unless you had near pristine/new plugs so each season we replaced them. Do I need to do the same with the Raptor?