plugs for a 350 MAG MPI Horizon

[1Moredrift]

I have a 2001 350 MAG MPI Horizon that takes AC41-932 plugs. They reccomend changing the plugs every three years, last year was year number 4. <br /><br />When I looked at the plugs, they looked to be in good shape (clean) and the boat is running fine (I think my mechanic may have replaced them when they were troubleshooting a bad ECM a year ago).<br /><br />My questions are:<br /><br />1. Could the plugs require replacement even if they appear to be in good condition and I am experiencing no symptoms.<br /><br />Should I replace them with the AC41-932 plugs $16/plug or are there better plugs for the same price/equal plugs for less?

 

[Limited-Time]

Re: plugs for a 350 MAG MPI Horizon

1Moredrift,<br /> I live by the phrase "if it ain’t broke, don't fix it" That said any thing that needs regular servicing to increase the products life I do, like oil & filter changes. Our currant boat is on its 9th season with nothing but yearly greasing, and oil and filter changes. I once had a 93 Ford Bronco went 93,000 miles before it started running rough. The mechanic was surprised when he discovered all the ignition components were factory original. As for changing plug types, if you can not find a direct cross over that’s less expensive I would stick with the factory spec. product.<br /><br /><br /> L-T

 

[newport dave]

Re: plugs for a 350 MAG MPI Horizon

Can you find out for sure if they changed the plugs last year? If your not sure, I would change them. After all, if you don't change them now are you going to wait and wonder for another two to three years?<br /><br />You won't find those (platinum tipped) plugs for much less, regardless of brand. I'd use the AC plug.<br /><br />Dave

 

[vipzach]

Re: plugs for a 350 MAG MPI Horizon

I gotta go with what has been said "if it aint broke don't fix it", If you just want to do it and they weren't changed last year, stick with what you have. They seem to be working great for you.

 

[bluewater19]

Re: plugs for a 350 MAG MPI Horizon

I just went through the same thing with my 2003 4.3 same # double platnum and thought 16.00 was a bit steep. <br />go to www.sparkplugs.com and put in 41932 and it will spit out a bunch of cross referenced plugs. this is what I did and found double platnum for as low a $6.00<br />Good luck

 

[cc lancer]

Re: plugs for a 350 MAG MPI Horizon

1Moredrift<br />One of my relatives is a GM-Mr. Goodwrench, and refers to that plug as the 100,000 mile plug. And I was advise NOT to go with a cheaper plug. I would take them out each year, maybe clean them, they will "tell" you when they start to die.

 

[bluewater19]

Re: plugs for a 350 MAG MPI Horizon

CC lancer, <br />If you take them out each year to clean them you might as well replace them with regular AC-MR43ts every year. What you are saying makes no sense. My father is also " MR goodwrench" He has worked for our local gm dealer for over 30 years and is a factory trained tech. He thinks that the double platnum AC delco "100,000 mile" plugs are overpriced even at dealer cost and recomended for me to use NGK or denso double platnum. Great plugs less cost.<br /><br />These motors are under way more stress than any car or light truck ever thought of being. <br />I took my plugs out after only 2 seasons on my boat and the stock AC 41-932 double platnum plugs were toast.<br />What works in your car doesn't always apply to your boat. What would your car plugs look like if all you did was tow a trailer uphill all season?Thats the type of load your boat motor is under almost the time.<br />Think about it.

 

[cc lancer]

Re: plugs for a 350 MAG MPI Horizon

If you take them out each year to clean them you might as well replace them with regular AC-MR43ts every year. What you are saying makes no sense. My father is also " MR goodwrench" He has worked for our local gm dealer for over 30 years and is a factory trained tech. He thinks that the double platnum AC delco "100,000 mile" plugs are overpriced even at dealer cost and recommended for me to use NGK or denso double platnum. Great plugs less cost.<br /><br />Iam sure that opinions with every factory trained GM Goodwrech varies across the country. And I respect your father opinion, but why throw away a 16.00 part that is still good, and Mercruiser who has done extensive test on their engine says replace every 3 years. the ones in our company van has 87K on the plugs and and mileage is still near original and we pull some heavy boats with it.<br />Air craft plugs are cleaned and reinstall every annual inspection, the AI decides if the plugs warrant replacement.<br /><br />These motors are under way more stress than any car or light truck ever thought of being.<br /><br />The most load is getting the boat on plane, after that the load is no more than pulling a 6 K pound boat down the highway. Remember Bondo's recent post of getting 2500 hours out of a 302 Ford? If the stress factor was so high there is no way an engine would last that long.<br /><br />I took my plugs out after only 2 seasons on my boat and the stock AC 41-932 double platnum plugs were toast.<br />What works in your car doesn't always apply to your boat. What would your car plugs look like if all you did was tow a trailer uphill all season?Thats the type of load your boat motor is under almost the time.<br />Think about it.<br /><br />I don't run my boat wide open and some people do, their choice. But after the boat is on plane and trimmed, the load is reduced on the engine. And we have plenty of hills here in the piedmont of NC.