Go Back  Offshoreonly.com > Technical > General Q & A
How long will my spark plug last? >

How long will my spark plug last?

Notices

How long will my spark plug last?

Thread Tools
 
Old 05-23-2012, 01:48 PM
  #1  
Registered
Thread Starter
 
Join Date: Apr 2005
Posts: 54
Received 6 Likes on 1 Post
Default How long will my spark plug last?

I have a 496HO @ 275 hours and still running strong without any issues so far. I wonder when to replace my original AC Delco plugs 41-983. When I ask around I get all kinds of advice from right now to wait until the motor reach at least 1000 hours.
SCANDINAVIAN is offline  
Old 05-24-2012, 08:49 AM
  #2  
Registered
 
Join Date: Apr 2007
Location: Peoria, AZ
Posts: 105
Likes: 0
Received 0 Likes on 0 Posts
Default

Stock motor with decent fuel I did mine at 300 hours.
Chico&Zeus is offline  
Old 05-24-2012, 09:36 AM
  #3  
Registered
 
Join Date: Dec 2011
Location: Colonial Beach, VA
Posts: 272
Likes: 0
Received 0 Likes on 0 Posts
Default

275 hours on mine with no issues. Will probably change them out at the end of the season or beginning of next though.
Redhook98 is offline  
Old 05-24-2012, 09:51 AM
  #4  
Platinum Member
Platinum Member
 
Join Date: Dec 2002
Location: Dallas, TX
Posts: 2,195
Likes: 0
Received 2 Likes on 2 Posts
Default

We run hard at mostly 4500+ RPM. Our plugs Autolite AR 3911plugs are toast after 15-20 hrs. They are worn and would need to be re-gapped. We change plugs annually. If you mostly cruise, plugs will last a long time.
BenPerfected is offline  
Old 05-24-2012, 10:39 AM
  #5  
Registered
 
Join Date: Jan 2004
Location: San Diego, California
Posts: 2,777
Likes: 0
Received 6 Likes on 6 Posts
Wink

In Europe you tend to have a higher octane and better blend of fuel than we have here in the USA. The platinum tip 41-983 plugs are a little sensitive to fuel and the quality of the burn in the cylinder, but they should give you a 300-hour service life and if you develop a slight loss of power or a had starting or definite misfire issues then change them at that time no matter what. Spark plugs are relatively moderatly priced replacement part but still remember my favorite saying here" If it Ain't Broke, Don't fix it!"

Best Regards,
Ray @ Raylar
Raylar is offline  
Old 05-24-2012, 01:15 PM
  #6  
Registered
 
Knot 4 Me's Avatar
 
Join Date: Jun 2005
Location: Central IL
Posts: 8,363
Received 749 Likes on 402 Posts
Default

Got 330 hours on the stock plugs in my 2003 496 MAG. Boat starts and runs like new. Might consider changing them out at 400 hours. Or maybe 500...
Knot 4 Me is offline  
Old 05-24-2012, 03:18 PM
  #7  
Registered
 
Join Date: Aug 2005
Location: Ray Twp. Michigan
Posts: 812
Likes: 0
Received 1 Like on 1 Post
Default

I changed plugs on my stock 502 mpi mags after 350 hours and really didnt notice a difference, probably could have went to 400 hrs.
johnny b good is offline  
Old 05-25-2012, 02:09 PM
  #8  
Registered
Thread Starter
 
Join Date: Apr 2005
Posts: 54
Received 6 Likes on 1 Post
Default

Thx all for Your replies!
Looks like I´m getting close to the limit for new plugs. And yes, as Ray wrote, we have a higher octane level here in Europe, I use 95 octane. Perhaps it gives my plugs a bit longer lifetime, so far no loss in performance.
SCANDINAVIAN is offline  
Old 05-28-2012, 03:46 AM
  #9  
Registered
 
Join Date: Feb 2007
Location: Sweden
Posts: 161
Likes: 0
Received 0 Likes on 0 Posts
Default

Scandinavian, this is where it gets confusing ;-)
Our 95 octane (RON) equals 91 octane (PON) they have in the states.
PON=(RON+MON)/2

Regarding the plugs I have noticed they can run several hundred hrs and then fail completely.
The only way to notice is at full rpm when you will loose a couple of hundred's.
At idle it is very hard to notice since the PCM maintains preset rpm by opening up IAC to give remaining running cylinders more air.
Alex is offline  

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On



Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.