spark plugs for 4.3 merc - 1997

[rderenzy]

question....
about to change my spark plugs, manual says 35-59571 but auto parts store couldn't match it.
google shows it converts to a NGK4323 (I think)
they didn't have NGK, so a matched model to that is R42T ... but when I got home and looked it up, that ngk model matches ALOT of ac delco brands

AC Delco	MR43T
AC Delco	R42CT
AC Delco	R42T
AC Delco	R43CT
AC Delco	R43T

Further more, I pulled on plug out (which they sold me 2 years ago) and its a ac delco MR43LTS (which doesn't convert to the NGK4323 - looks like only the MR43T does)

any way to tell which one I actually need?


LTS on the left, R42T on the right

 

[Bondo]

and its a ac delco MR43LTS (which doesn't convert to the NGK4323 - looks like only the MR43T does)

Ayuh,..... I run the AC MR43T plugs in mine, with Pre-Vortec heads,.....

The MR43LTS is longer for the Vortec heads, bein' a '97, should have,.....

Btw,..... The M in the part number means Marine, which uses an alloy, rather than steel for the bodies,....

 

[rderenzy]

Ayuh....so what do I do....do I buy the MR43T? use the ones they gave me (R42T)? or try to get what I've used the past two years, MR43LTS? I don't want t o do all the work and it fires like crap or wont start or is wrong. don't understand why they say 5 different spark plugs match the nKG model that fits my number in the manual - 1997, 4.3 merc, lx gen+

I don't know what the M (guessing marine), R, T or L (long?), or S means

just want to replace my dam plugs

I'm not an engine guy - sorry :/

 

[Bondo]

Ayuh,.... You posted as I was typin' yer answers,.....


Hmmmmmmmmm,........ Haveta add Mind Reader to the resume,......

 

[rderenzy]

nice, thanks for that. so I should definitely go back and get the M grade yes? wtf would they sell me a non Marine plug

SO! I still am not clear what i'm shooting for - but I guess that limits the choices down to a M43T or M43TLS - which one is for my engine?

 

[Bondo]

or M43TLS - which one is for my engine?

Ayuh,.... Yer motor should have Vortec heads,.....

'n there's absolutely Nothin' wrong or worn on the plugs yer takin' out,....

 

[rderenzy]

ok, so i'll go return the M42T they gave me for what I have been running - M43TLS ...BUT M43TLS does not match the merc manual for part number

33-59571 ​

- so WTF!!!!!!!!!! shouldtn be this complicated

i'm replacing them because they have been used for 2 years and loaded with fogging oil

 

[Bondo]

i'm replacing them because they have been used for 2 years and loaded with fogging oil

Ayuh,.... Put 'em back in, 'n go for a boat ride,..... 1/2 hour at 3/4 throttle, they'll be as good as new,....

 

[GA_Boater]

Scan the rest of the you copied from;

http://www.sparkplug-crossreference....rt/NGK_PN/4323

 

[rderenzy]

Ayuh,.... Put 'em back in, 'n go for a boat ride,..... 1/2 hour at 3/4 throttle, they'll be as good as new,....

what...for real, you don't replace your plugs? I always have troublestarting all my stuff after a few years (power washer, motor cyle) and I take the plug out and replace or I wipe it down (give it a good scrub) and its starts first pull/kick/turn

 

[rderenzy]

Scan the rest of the you copied from;

http://www.sparkplug-crossreference....rt/NGK_PN/4323

yep, that's the list...and still doesn't list the MR43LTS that I got sold 2 years ago and have been using

 

[rderenzy]

http://store.usavediscountmarine.com/mobile/Product.aspx?ProductCode=603-MR43LTS

looks like the Lts that I was sold and used the last two years isn’t listed for my model

I’ll go with the m43t which is what is listed.
Thanks all

 

[GA_Boater]

I can't find the MR43LTS anywhere, not even on the AC Delco site. Probably with replaced with MR43T by AC Delco.

 

[rderenzy]

I’ll check tomorrow but it doesn’t look as long as the lts. But if the plug I was using is longer than it’s supposed to be... wouldn’t that have given me issues?

 

[Bondo]

Ayuh,..... Count the bolts holdin' the intake manifold on,.....

If there's 4 on each side, ya Need the longer spark plugs, the ones ya took out,.....

If there's 6 on each side, ya need the MR43T spark plugs,.....

'n,... Yes, I'm serious,... There's Nothin' wrong with the plugs ya took out,.....they're in perfect condition,.....

 

[Scott Danforth]

Ayuh,..... Count the bolts holdin' the intake manifold on,.....

If there's 4 on each side, ya Need the longer spark plugs, the ones ya took out,.....

If there's 6 on each side, ya need the MR43T spark plugs,.....

'n,... Yes, I'm serious,... There's Nothin' wrong with the plugs ya took out,.....they're in perfect condition,.....

next thing they will be replacing the coil

 

[JoLin]

If you're set on changing them, Delco M43LTS for Vortec engines as Bondo described above (1996-up). The NGK equivalent is BPR6EFS.

 

[rderenzy]

If you're set on changing them, Delco M43LTS for Vortec engines as Bondo described above (1996-up). The NGK equivalent is BPR6EFS.

see, this is the problem....BPR6EFS does not equate to my engine manual, refering to 35-59571
and if you look up BPR6EFS, my engine is not listed (see previous link from previous comment)


What would happen if i bought the short ones and it required long, or bought the long one but requried short

 

[rderenzy]

Ayuh,..... Count the bolts holdin' the intake manifold on,.....

If there's 4 on each side, ya Need the longer spark plugs, the ones ya took out,.....

If there's 6 on each side, ya need the MR43T spark plugs,.....

'n,... Yes, I'm serious,... There's Nothin' wrong with the plugs ya took out,.....they're in perfect condition,.....

son of a b - i'm not home and want to get the plugs after work
no way it needs the LTS, look at what the models are
http://store.usavediscountmarine.com/mobile/Product.aspx?ProductCode=603-MR43LTS

compared to the normal T model, which has my exact engine listed
http://store.usavediscountmarine.com/mobile/Product.aspx?ProductCode=603-MR43T

 

[rderenzy]

If you're set on changing them, Delco M43LTS for Vortec engines as Bondo described above (1996-up). The NGK equivalent is BPR6EFS.

fk your right, i just used this site
https://www.sparkplugs.com/Marine-c436.aspx
and looked it up and it referes to the longer BPR6Efs

what a cluster f, half the sites say one, the other half another.


still dying to knw - what would happen if my engine required the longer park plug, but i put in the short spark plugs? woudlnt start? would notice it big time?