Spark Plugs

[pctarmor]

What plugs you guys running in the 325? I used AC Delco last year, not sure if there is a better option.

[cadunkle]

Not sure what the 325 is, sounds small! Anyhow, I'm using standard copper AC Delco MR43T regular copper plugs in my 454, and I have a set of NGK BR6FS to swap in whenever those need changing. They're plugs, they work just fine.

I'm considering an iridium plug for next time I buy plugs for the boat, as I got them for my CB750 and it made a big difference. Cold starts in one kick, smoother idle, eliminated most of the stumble when snapping throttle open quickly (carbs have no accelerator pump so lean stumble is normal if grabbing a handful at too low RPM). I was very pleased with the noticeable improvements the iridium plugs gave over standard copper. The most noticeable improvements were cold starts in cold weather, idle and low RPM smoothness, and generally smoother better response under ocnditions where I know the carbs aren't getting exactly the mixture it needs. Maybe a bandaid for carbs not tuned perfectly, but it seems like those iridium plugs will light off a less than ideal mixture more easily.

When my truck needed plugs I figured why not, and threw in iridium plugs. Truck has a 460 and I noticed improved cold starts and cold idle, felt a little smoother at lower RPM just off idle letting clutch out. Whether that was just because I was comparing to worn out copper plugs, I don't know. Seems to start a little easier. Differences between coipper and iridium in the 460 are much less than the differences on the bike. Maybe because a 750 double pumper is easier to tune than SOHC4 carbs on a modified engine.

Anyhow, if you got some moeny burning a hole in your pocket and want to try a different plug iridium have been pretty good for me. Can't hurt anything and may help if you have any ignition trouble. Just be careful setting the gap if you go that route, the tips are fragile.

[MJHKnox]

I've used the AC Delco for the last 2 years. Once I burn all the winter fogging oil from the motor, I change them every year. That's on a 2007 325hp.

8#41-993
19256067

Mark

[michael hunter]

Why are you changing the plugs so often? With today's fuels changing spark plugs is almost obsolete. You can go 100k on a car before even thinking about changing plugs. My recommendation is to put in the original brand and part number and don't think about them for the next 500 hours.

[CJD]

I think the reason modern plugs last so long was the introduction of platinum coatings. The platinum has almost no erosion, so the gap is consistent for up to 100k miles on a car. My 325 came with old style copper and steel electrodes, though. They erode and have to be checked more frequently. My impression is that, since Indmar figures you will be pulling the plugs every season to winterize, that you will be checking the gaps and condition of the plugs...so what's the point of putting platinums in?

[wotan2525]

I used to replace my plugs every spring as "maintenance." Two years ago, I pulled them out and they still looked brand new so I went... screw this..... I'll inspect them every year and replace them when they start to look "bad."

[MJHKnox]

Why are you changing the plugs so often? With today's fuels changing spark plugs is almost obsolete. You can go 100k on a car before even thinking about changing plugs. My recommendation is to put in the original brand and part number and don't think about them for the next 500 hours.

I think the manual has the maintenance of the plugs at 250 or 300 hours. If I put 100+ hours on them, it's not a big deal, they are easy to get replace and I get the at cost from auto parts store.

Overdone , , , , probably.

Mark

[michael hunter]

Something you have to consider every time yo touch anything there is a chance to cause a problem. Spark plug wires are carbon filled every time you pull or bend them you have the risk of internally breaking the carbon . The spark will start crossing the gap at the break and burning the carbon until the gap gets too big then the engine will start to miss on that cylinder. Other possibility's are breaking clips or holders damage to components or just disturbing wiring looms and causing electrical issues. Its not always good to mess with things some times better to let it be and just wait for a real problem. If it ain't broke don't fix it.