www.iFourWinns.com

I have a 1997 Horizon 180 with a 4.3L GL engine. I bought it at the end of last summer and for the most part it ran well. It was little hard to start after it sat for more than a week and idled a little rough.

In preparing for the new season I wanted to change the spark plugs, amongst other things. The tag on the engine calls for either AC MR43LTS or Champion RS12YC gapped to 0.045". I have purchased the RS12YC.

When I removed the existing plugs they are AC R43T. The length of the threads is consideribly shorter than the RS12YC's that I purchased. This means the tips of the old plugs were much shallower into the cylinder compared to the new RS12YC's that I installed.

I am paranoid that the piston will contact the new plugs. I know this is what the tag calls for, but I am just looking for reassurance that I am doing the right thing before I crank the engine over. It seems odd the engine would have even run with the old plugs, but I guess a spark is a spark, even it is occuring further away from the piston then intended.

Any comments/feedback is appreciated!

Tom

Not sure about the plugs you removed... but I know on my old 97 sundowner the engine would run very rough unless it had the GM AC Delco plugs in it which I believe is the first number you have there. So maybe some one at the a GM dealer ship could help you with this
Good Luck

_________________
2001 328 Vista "Nauta Dream 2"
AB Inflatable 10AL "Little Dreamer"
2000 248 Vista
1997 225 Sundowner


Mike

I've seen several posts on other boards that say the LTS plugs are only for use in Vortec engines. According to the AC Delco web site, LTS indicates "long reach tapered seat" and the M prefix indicates marine use.

http://www.acdelco.com/parts/sparkplugs ... cation.jsp

Any chance the label could be wrong?

_________________


Mike
2005 Four Winns 230/240
VP 5.7GXi/DP
1998 F-150 XLT
Boat Pic

Mike,

The engine is a Vortec, or at least that is what it says on the valve covers. The makes feel a little more comfortable that the label is correct and the old spark plugs were wrong. I will seach for Vortec in earlier posts and see what I can find.

Thanks!

Tom