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Nafplio
03-27-2007, 02:17 PM
Changing the spark plugs on the boat today. Engine Nut had recommended AC MR43LTS on a previous post. Looking for a torque requirement and can't find it in the owners manuals. Thanks.

Nafplio
03-27-2007, 04:01 PM
The new plugs are in. When I was taking the old ones off, they were breaking loose at 15-20 ft-lbs. Can anyone confirm that? Larry or Brian?

The block and v-drive drain plugs are also installed. Putting in a new fuel filter today. A new impeller tomorrow, and she'll be ready to rock & roll.

Engine Nut
03-27-2007, 06:17 PM
Changing the spark plugs on the boat today. Engine Nut had recommended AC MR43LTS on a previous post. Looking for a torque requirement and can't find it in the owners manuals. Thanks.

The spark plug torque specification in the GM service manual for the 5.7L engine is 11 lb ft or 15 Nm for you metric guys.

Engine Nut

Nafplio
03-27-2007, 06:31 PM
Thank you Engine Nut. You are the man!

04OUTBACK
03-27-2007, 07:07 PM
How many hours do you have on yours? How often should you replace the plugs?
Thanks!

Engine Nut
03-27-2007, 09:22 PM
How many hours do you have on yours? How often should you replace the plugs?
Thanks!

Indmar recommends changing spark plugs annually or every 300 hours, whichever comes first. All 5.7 Vortec engines use AC MR43LTS plugs gapped at .045" for EFI engines or.030"for carbureted engines. You could also use platinum tipped AC 41-932 plugs gapped at .060" for EFI engines or .030" for carbureted. I would save my $ and use the MR43LTS.

Engine Nut

04OUTBACK
03-27-2007, 09:39 PM
Thanks Engine Nut...
I only have 111 hrs on 04 but I bet the previous owner did not change them last year before selling.. Thanks for the gap info too!

BW

Nafplio
03-27-2007, 11:31 PM
About 240 hours. Normally, I change spark plugs and fuel filter at winterizing time. I also remove the old impeller. At the beginning of the new season, new impeller goes in. The Indmar manual has detailed winterizing/summerizing instructions. I've also printed a bunch of related (mostly Engine Nut's) posts for refference.

seanpatsdad
03-28-2007, 07:27 AM
I put the AC 41-932 in this year.Autozone wanted $65.00.I bought them at the local Carquest for $40.00.I go to Autozone now only to dump off old oil.
John

jclay5
04-11-2009, 11:29 AM
Indmar recommends changing spark plugs annually or every 300 hours, whichever comes first. All 5.7 Vortec engines use AC MR43LTS plugs gapped at .045" for EFI engines or.030"for carbureted engines. You could also use platinum tipped AC 41-932 plugs gapped at .060" for EFI engines or .030" for carbureted. I would save my $ and use the MR43LTS.

Engine Nut

Engine Nut, what sparkplug wires should I get for the 5.7l Vortec Engine (carbed)? Or if anyone else knows and wants to chime in that would be great.

jclay5
04-11-2009, 02:29 PM
found them =D