Need help with Spark plugs for 4.3l MPI

[achris]

Hi all,

Engine is 2006 Mercruiser 4.3 MPI with 210hrs. I've noticed the last few trips out that when I'm flushing it the engine has a problem in the 1000 to 1500 rpm range. It WILL NOT sit there. The owners guide states that the engine needs to be at 1300 +/- 100 when on flushers (to prevent water reversion). Try and make it do it and it coughs and splutters badly.

I had a similar problem with the previous engine (1994 4.3LX) and it was always solved by replacing the spark plugs. I usually got about 250 hours before the problem, so I started replacing them at 200 hours.

Now, with this engine the plugs are Iridium, expensive, and suppose to last 10 years... Yeah right!!! Less than 4!

Here's the problem. For NGK TR55IX I'm being quoted around $25ea , and nobody is carrying the platinum ones (TR55GP) which should be less than half the price. The most annoying thing is that I see the Iridium plugs on websites in the US for less than $8 ea, but they want over $50 for freight, for 6 spark plugs!!... Talk about being ripped off!!! Looks like I'm screwed either way I go. This is going to make it one very expensive engine to keep feeding plugs to every 200 hours.

Any suggestions?

Thanks for your help guys.

Chris............

 

[JustJason]

Re: Need help with Spark plugs for 4.3l MPI

Hey Chris,

Why not just replace them with regular NGK's or AC's that you can source locally? You don't really get any extra performance or milage or anything with the iridiums. And the rest of the ignition system isn't going to care. All you get is an extended service interval with the plugs by going to the precious metals. All you would have to do is get back into the habit of changeing them every season/200 hours.

I can get a price for you on what they cost out my way and see what it would cost to get a set to you. If you have paypal I wouldn't mind doing it. Tuesday would be the earliest I could get to it though, And I don't know your time schedule.

 

[achris]

Re: Need help with Spark plugs for 4.3l MPI

Hi Jason...

Someone did suggest I could use NGK BPR6EFS (the plug used in the Gen + TBI engines).

I was hoping that someone here may have experience running them and let me know, but I definitely don't want to be throwing $150 worth of plugs at this thing year. I don't have a problem with changing them frequently, I like to do a compression test anyway and the plugs need to come out for that, so it doesn't make any difference.

Cheers,

Chris.....

 

[Fun Times]

Re: Need help with Spark plugs for 4.3l MPI

Hi all,

Engine is 2006 Mercruiser 4.3 MPI with 210hrs.

Now, with this engine the plugs are Iridium, expensive, and suppose to last 10 years... Yeah right!!! Less than 4!

Here's the problem. For NGK TR55IX I'm being quoted around $25ea , and nobody is carrying the platinum ones (TR55GP) which should be less than half the price. The most annoying thing is that I see the Iridium plugs on websites in the US for less than $8 ea, but they want over $50 for freight, for 6 spark plugs!!... Talk about being ripped off!!! Looks like I'm screwed either way I go. This is going to make it one very expensive engine to keep feeding plugs to every 200 hours.

Any suggestions?

Thanks for your help guys.

Chris............

Hi Chris, I'm not sure where your getting your NGK spark plug part numbers from, But by going by the engine serial number you posted, (OW617679) the newest NGK number mercruiser recommends using in that engine is part number 33-8M2018369 NGK ITR4A15 @4.

As you can see below, the part numbers have Superseded over the years, Here is the Superseded list for you to see.

Item Supersession Chain:

Row Class Part Number SS Level Disp Description
(1) 33-8M2018369 00 ACT NGK ITR4A15 @4 MSRP: $19.30

(2) 33-884019001 01 SS AC 41-993 @8

(3) 33-884019 02 SS AC 41-932 @8

Also see the "note" on number 14 in this link.
http://www.mercruiserparts.com/Show...r=50&bdesc=Distributor+and+Ignition+Componets

This was your original part number from merc, 884019 and now it has Superseded to 8M2018369.

http://www.georgiawatersports.com/ProductCart/pc/viewPrd.asp?idproduct=206727&idcategory=2746

http://www.google.com/search?sourceid=navclient&ie=UTF-8&rlz=1T4ADRA_enUS351US351&q=NGK+ITR4A15+

Good luck to you with it.

 

[achris]

Re: Need help with Spark plugs for 4.3l MPI

Hi Chris, I'm not sure where your getting your NGK spark plug part numbers from, But by going by the engine serial number you posted, (OW617679) the newest NGK number mercruiser recommends using in that engine is part number 33-8M2018369 NGK ITR4A15 @4.

Got the number from NGK website. They list TR55IX as an AC 41-932 equivalent, also comes up when I used the drill-down for this engine. http://www.ngk.com/results_appOther.asp?otherMotiveID=215648&mfid=1

As you can see below, the part numbers have Superseded over the years, Here is the Superseded list for you to see.

Item Supersession Chain:

Row Class Part Number SS Level Disp Description
(1) 33-8M2018369 00 ACT NGK ITR4A15 @4 MSRP: $19.30

(2) 33-884019001 01 SS AC 41-993 @8

(3) 33-884019 02 SS AC 41-932 @8

Also see the "note" on number 14 in this link.
http://www.mercruiserparts.com/Show...r=50&bdesc=Distributor+and+Ignition+Componets
This was your original part number from merc, 884019 and now it has Superseded to 8M2018369.

http://www.georgiawatersports.com/ProductCart/pc/viewPrd.asp?idproduct=206727&idcategory=2746

http://www.google.com/search?sourceid=navclient&ie=UTF-8&rlz=1T4ADRA_enUS351US351&q=NGK+ITR4A15+

Good luck to you with it.

Great , now the 'right' plugs are even more expensive. (We are paying about 2 1/2 times what you guys pay, so those $19.30 plugs are REALLY pricey here).

Thanks for the info BT. Just another nail in the Mercruiser coffin. I?ll probably go for a Volvo diesel next time it comes up for re-power.

 

[Don S]

Re: Need help with Spark plugs for 4.3l MPI

It's not just Mercruiser with those plugs Chris, Volvo uses the same thing.
You think spark plugs are a big expense, wait till you see the maintenance and parts prices on the new Volvo diesels

Just out of curiosity, what does your boat weigh at normal cruise weight?

 

[Fun Times]

Re: Need help with Spark plugs for 4.3l MPI

I just called my local pep boys auto parts store and he said they are $9.99 each for the NGK part number ITR4A15 But they are special order for that store.

Then if you look up mailing them from here it looks like it could be done for about $13.45
Priority Mail? International Small Flat Rate Box*
Maximum Value for Contents: $400.00
USPS Supplied Small Box: 8 5/8" x 5 3/8" x 1 5/8".
Maximum weight 4 pounds. 6 - 10 business days $13.45 $12.78

http://ircalc.usps.gov/MailServices.aspx?country=10013&m=13&p=0&o=1&mt=13

How desperate are you?

 

[achris]

Re: Need help with Spark plugs for 4.3l MPI

It's not just Mercruiser with those plugs Chris, Volvo uses the same thing.
You think spark plugs are a big expense, wait till you see the maintenance and parts prices on the new Volvo diesels

Just out of curiosity, what does your boat weigh at normal cruise weight?

Yeah, I know... Boating is expensive. The plugs aren't a 'big expense', I just think they are ridiculously expensive (in Australia).

Boat weight is a good question. Probably 3,000 - 3,500 lbs. The sales brochure says 2,500lbs, but I have a lot of gear on board, and I would think that's also a dry weight.

Chris........

 

[Don S]

Re: Need help with Spark plugs for 4.3l MPI

I have to run some numbers in the Volvo Engine configurator
http://www.volvopenta.com/VOLVOPENT...E_CONFIGURATOR/Pages/engine_configurator.aspx

Just to see what happens with a D3 diesel.

 

[Don S]

Re: Need help with Spark plugs for 4.3l MPI

Well, that little D3-190 diesel should push a 3000 lb boat (weight without engine) to the 44 mph range.
I've also found that configurator to be a bit conservative on top speed. usually in the 3 to 4 mph range.

We won't even talk about the price of one. Volvo is very proud of them.

 

[achris]

Re: Need help with Spark plugs for 4.3l MPI

Thanks Don... I'll have a talk to Volvo Australia and see if I can stay standing. ....

Chris.....