It's amazing.....
#1
Registered
Thread Starter
It's amazing.....
How some people can be so lazy when purchasing spark plugs for a boat. Who in there right mind would by auto lite spark plugs for 454/420's? The port motor in my 1988 Formula 311 was running a little sluggish compared to the starboard motor so I decided to have it checked out. Pier 53 marina in Sandusky, OH told me it needed a tune up when they did the tranny work on it, so I was gonna do it in the spring but decided to have it checked out sooner so I wouldn't have to worry about it in the spring.
I'm having Kunkel's Marina near Mansfield OH do the work and the owner Jason calls me today and tells me that the motor has auto sparkplugs in it, I'm thinking WTF! turns out at one time there must have been a water leak somewhere near the #7 plug which caused it to rust and break apart so #7 wasn't firing at ALL. So that means the head has to come off and drill it out. Hopefully thats all that is wrong with it and he'll replace the AUTO plugs with Marine Plugs. Unbelievable.
I'm having Kunkel's Marina near Mansfield OH do the work and the owner Jason calls me today and tells me that the motor has auto sparkplugs in it, I'm thinking WTF! turns out at one time there must have been a water leak somewhere near the #7 plug which caused it to rust and break apart so #7 wasn't firing at ALL. So that means the head has to come off and drill it out. Hopefully thats all that is wrong with it and he'll replace the AUTO plugs with Marine Plugs. Unbelievable.
#2
Charter Member # 55
Charter Member
There is nothing wrong with running automotive plugs in a marine engine as long as they are the correct plug. Marine spark plugs are pretty much the same except some brands of the marine plugs have an SS coating to prevent corrosion.
You stock plugs should be an AC MR43T. They are the same as an R43T except for the SS plating. Also the same an AC Rapid Fire #1 which has an SS coating.
There is a lot more selection for automotive plugs as well.
You stock plugs should be an AC MR43T. They are the same as an R43T except for the SS plating. Also the same an AC Rapid Fire #1 which has an SS coating.
There is a lot more selection for automotive plugs as well.
#3
Registered
There is nothing wrong with running automotive plugs in a marine engine as long as they are the correct plug. Marine spark plugs are pretty much the same except some brands of the marine plugs have an SS coating to prevent corrosion.
You stock plugs should be an AC MR43T. They are the same as an R43T except for the SS plating. Also the same an AC Rapid Fire #1 which has an SS coating.
There is a lot more selection for automotive plugs as well.
You stock plugs should be an AC MR43T. They are the same as an R43T except for the SS plating. Also the same an AC Rapid Fire #1 which has an SS coating.
There is a lot more selection for automotive plugs as well.
#4
Brotherhood #1
Gold Member
I run the racing autolite automotive plugs. But maybe your right im out of my mind. There is no issue with running the plugs. Ive never had a problem what so ever also I agree with griff on all points. Although there is a differance when you do your own work you get down in the bilge and always checking everything evertime the hatch opend just for piece of mind. I enjoy being a bilge rat ask any CT member on the board. Come down to making sure the the salt (if thats what you run in) is washed off completly and doing maintance when do and preventitive maintance.
-Mike
-Mike
#5
Registered
I replaced the plugs on a 7.4MPI once only to find they had been replaced by the previous owner with the wrong length plugs. I was amazed the motor ran as well as it did without the correct extended tip plugs. Heat range and length are the most important things to get right on a plug.
#6
Registered
How some people can be so lazy when purchasing spark plugs for a boat. Who in there right mind would by auto lite spark plugs for 454/420's? The port motor in my 1988 Formula 311 was running a little sluggish compared to the starboard motor so I decided to have it checked out. Pier 53 marina in Sandusky, OH told me it needed a tune up when they did the tranny work on it, so I was gonna do it in the spring but decided to have it checked out sooner so I wouldn't have to worry about it in the spring.
I'm having Kunkel's Marina near Mansfield OH do the work and the owner Jason calls me today and tells me that the motor has auto sparkplugs in it, I'm thinking WTF! turns out at one time there must have been a water leak somewhere near the #7 plug which caused it to rust and break apart so #7 wasn't firing at ALL. So that means the head has to come off and drill it out. Hopefully thats all that is wrong with it and he'll replace the AUTO plugs with Marine Plugs. Unbelievable.
I'm having Kunkel's Marina near Mansfield OH do the work and the owner Jason calls me today and tells me that the motor has auto sparkplugs in it, I'm thinking WTF! turns out at one time there must have been a water leak somewhere near the #7 plug which caused it to rust and break apart so #7 wasn't firing at ALL. So that means the head has to come off and drill it out. Hopefully thats all that is wrong with it and he'll replace the AUTO plugs with Marine Plugs. Unbelievable.
Don't believe everything you are told unless you know for yourself. Otherwise, you will go on to a forum and tell a bunch of DIY'ers how you let your mech. blow smoke up your a$$.
I ran autolite's in by marine 572's. They were the only plug that they really "liked".
Last edited by TxHawk; 11-15-2011 at 01:20 PM.
#7
Registered
Thread Starter
I run the racing autolite automotive plugs. But maybe your right im out of my mind. There is no issue with running the plugs. Ive never had a problem what so ever also I agree with griff on all points. Although there is a differance when you do your own work you get down in the bilge and always checking everything evertime the hatch opend just for piece of mind. I enjoy being a bilge rat ask any CT member on the board. Come down to making sure the the salt (if thats what you run in) is washed off completly and doing maintance when do and preventitive maintance.
-Mike
-Mike
#8
Charter Member #1171
Charter Member
+1 as long as heat and length are correct no issues especially inland.
I always ran AC rapid fire #1 in my 502's in Chicago
I always ran AC rapid fire #1 in my 502's in Chicago
__________________
I want to live in a world where a chicken can cross the road and not have its motives questioned.
I want to live in a world where a chicken can cross the road and not have its motives questioned.
#9
Registered
I found the same with my new to me boat. Plugs were short version, not extended length. Boat ran great, as far as I could tell. I put correct plugs in M43RT. ...hoping to get another MPH out of it now. ;-)
I replaced the plugs on a 7.4MPI once only to find they had been replaced by the previous owner with the wrong length plugs. I was amazed the motor ran as well as it did without the correct extended tip plugs. Heat range and length are the most important things to get right on a plug.
#10
Geronimo36
Gold Member
I'm having Kunkel's Marina near Mansfield OH do the work and the owner Jason calls me today and tells me that the motor has auto sparkplugs in it, I'm thinking WTF! turns out at one time there must have been a water leak somewhere near the #7 plug which caused it to rust and break apart so #7 wasn't firing at ALL. So that means the head has to come off and drill it out. Hopefully thats all that is wrong with it and he'll replace the AUTO plugs with Marine Plugs. Unbelievable.
I'd pay for an hour's worth of labor trying to do that before paying to R&R a head.