Spark Plug for my boat

alexvelarde

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Mar 4, 2011
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I recently bought a 2013 Chaparral and I would like to change the spark plugs.
Do you know which Spark Plugs I should get? Is there a particularly better kind?

Engine Serial Number: 2A047298
 

alldodge

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Merc shows NGK ITR4A15

Also my guess is you don't need plugs
 

Bt Doctur

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And if you did , MR43LTS work just as good and a heck of a lot cheaper
 

alexvelarde

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Mar 4, 2011
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The boat was bought new in June 2014 and the original owner only put 28 hours on the engine in 2 years... I do not know if this has been enough use for the boat and I thought changing the spark plugs would be a good idea. I have put an additional 20 hours on it since June 2017. Any thoughts?
 

alldodge

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IMO (others will vary) plugs won't ever need to be changed unless you see issues with performance. My Rinker which I bought new had the original plugs in it (Champion) until 2 years ago. They all looked good, after replacing I noticed no difference and still don't. Now the cap and rotor are a different story, inspect every couple years and replace when anything is noticed
 

thumpar

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The only time I have ever replaced plugs because of a problem is in a 2 stroke because they can foul easy. Just think about your vehicles. How often have you placed plugs in your car or truck. I do replace plugs after a while but that is 100k+ miles and only out of regular maintenance and not because they are bad. 100k miles is probably around 2500 hours or more on an average vehicle.
 

Bondo

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Ayuh,..... I'm pushin' 2,000 hours with my 4.3l, I've changed the AC Delco MR-43T spark plugs, twice,....

It didn't need 'em either time, 'n they're now bouncin' 'round in the boat toolbox,....

Fuel filters are important to change,... often,.....

Not so much spark plugs, cap, rotor, or wires,...
 

QBhoy

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I thought it was the AC Delco 41-101 that replaces he old type ?
Hope it is...I just bought some for my 5.0 mpi.
Apparently don't need changed every year though. Think the plugs in mine from 2003 are the original ones. Only 150 hours ran though.
 

FreeBeeTony

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I change mine every other year........only have 2 sets.
​Basically clean 'em and put 'em back in...........
​Just force of PM I guess..........
 

QBhoy

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Mar 10, 2016
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I used to change mine every year when I had the carb engines. Cheap enough to do so.
Apparently the irridium tipped plugs in the MPI engines just don't need changed so much.....thankfully ??$?$$
 

s.hadley81

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Jun 22, 2011
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245
I have to agree with others! I change mine along with wires,cap,rotor every few seasons and I never noticed a difference. I changed my plugs on my truck at 85k miles and also didn't notice a difference.
 

Fun Times

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The boat was bought new in June 2014 and the original owner only put 28 hours on the engine in 2 years... I do not know if this has been enough use for the boat and I thought changing the spark plugs would be a good idea. I have put an additional 20 hours on it since June 2017. Any thoughts?
For this engine model, The service manual suggest checking the spark plugs, wires and Cap every 300 hours or 3 years....More typically in cases like these with low hours, the 3 year inspection would sort of more depend on how or what conditions the boat is used or stored in and if there are/have been any water leaks dripping down from the exhaust system or often have water inside the bilge area or maybe a high amount of condensation/humidity levels (things of that nature) causing corrosion type build up on the outside of the plugs due to sitting outside, etc. as you don't really want the plugs to get a heavy build up of rust preventing you from being able to remove them someday more easily.
Running/Sitting in or around salt water tends to create corrosion issues sooner than later too. So as for a performance standpoint at this time, you should be good to go. The weak point for this ignition system though is sometimes the HVS (High Voltage Switch) distributor cap.
http://www.iboats.com/Distributor-An...iew_id.1683509
http://www.iboats.com/5-0L-MPI-ALPHA...iew_id.1683626
 
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