Spark plugs... Done

[tdonoughue]

No pics on this one. Too much of a rush today.

But I changed the spark plugs, having hit 50 hrs on the boat. Man, talk about easy. I think I had them all done in about 30 min. Much easier than the oil change.

I know there is a writeup on here already, so I won't go through the steps (unless someone requests--then happy to). I just got a set of tools that allow you to put the sockets onto your drill chuck. Used that to zip the coil screws and the plugs out in record time. Made putting them in a breeze, too (but start the threads first and be VERY careful with the plugs as you don't want to over tighten).

So, if you are thinking to try this project and not sure, let me assure you it is an easy one. And it makes me that much more uneasy about having paid $450 for the 10 hr service at the shop...

Happy boating.

 

[itsdgm]

Great job. Saving money is fun. Especially when you can do it while spending time in the boat.

I'm not at all fimilar with the engines & plugs in your model of boat but I've found that the best plug wrench came in my Yamaha tool pouch. I like to use hand tools though to eliminate any chance of snapping off a plug in the head or stripping out a bolt here or there. Just a personal preference.

Again, congrats on finishing a job well done.

 

[tdonoughue]

I cheated a bit on the tool front. I am also a bit of a gear head, so I have been changing car plus since I was 13 or so. So I had all of the sockets for all sizes of plugs, extension bars, etc.

I was just surprised even at that at how easy it all was.

 

[davel501]

I cheated a bit on the tool front. I am also a bit of a gear head, so I have been changing car plus since I was 13 or so. So I had all of the sockets for all sizes of plugs, extension bars, etc.

I was just surprised even at that at how easy it all was.

No kidding. I do my plugs while the vacuum pump is pulling the oil out of the pan. Works out well, just give it a couple of pumps between plugs 3 and 4 and you are ready to finish the oil change after plug 4.

 

[Big Shasta]

I'm sure you were careful about how much torque you put on them going back in but reading about broken plugs I'd be afraid to put them back in with anything but my hands. Anti Seize also, right?

 

[jawsf16]

I always use the stock spark plug kit. It works great.

 

[davel501]

I don't antiseize anymore but I did once so there is still some in there. With the stock t handle you can feel the rings crush. It usually takes between a quarter and half turn but it is not consistent within that range. Sometimes a quarter turn, sometimes a half, sometimes a third.

 

[tdonoughue]

I did use anti-seize on mine. I was very gentle with the tightening. I was able to put the drill on the minimum clutch and only speed setting (as opposed to torque). As soon as it was about to touch I would let off and stop as soon as it hit. I would NOT recommend that technique for everyone. As mentioned, if you don't know your drill and your plugs very well, you WILL overtighten.

Only 1/4 turn or a bit less after touchdown, but that bit was manual, of course, with the ratchet.

 

[Cotay]

I changed mine yesterday and it was rather easy. I double checked my gap and thought I was good to go. The port side runs fine, but the starboard engine is now running rather rough...I tightened down about 1/8 turn after hand tightening. I think I need to pick up some new plugs to do this one over.

The odd thing was the original owner had obviously not gapped his plugs...they ranged from .28 to .45 across both engines. Funny thing was that both engines ran fine before. I changed them out because the prior owner had overfilled the oil and the plugs and air filters had fowled a bit.

I'm curious where I went wrong...maybe I just need to check my connections and tighten them down a bit more?

 

[davel501]

If you use the t handle that came with the boat you will feel the plugs go from easy turning to slow when you are crushing the gaskets to hard when they are smashed. I put enough force on the wrench to crush the gasket but not torque it beyond that. It is different for every plug.

 

[Cotay]

If you use the t handle that came with the boat you will feel the plugs go from easy turning to slow when you are crushing the gaskets to hard when they are smashed. I put enough force on the wrench to crush the gasket but not torque it beyond that. It is different for every plug.

Sadly, my used boat didn't have the T-handle when I purchased it. But I have plenty of deep spark plug sockets and extensions...I used those for the change and felt what you describe. It was no different than any spark plug change I've done in cars or motorcycles for the past 30 years...so I'm guessing I just got my gap wrong...although I checked each one three times (once when I bought them, and twice yesterday).

 

[Big Shasta]

I changed mine yesterday and it was rather easy. I double checked my gap and thought I was good to go. The port side runs fine, but the starboard engine is now running rather rough...I tightened down about 1/8 turn after hand tightening. I think I need to pick up some new plugs to do this one over.

The odd thing was the original owner had obviously not gapped his plugs...they ranged from .28 to .45 across both engines. Funny thing was that both engines ran fine before. I changed them out because the prior owner had overfilled the oil and the plugs and air filters had fowled a bit.

I'm curious where I went wrong...maybe I just need to check my connections and tighten them down a bit more?

Were you using iridiums? the tips are very brittle on them if you checked the gap on them it's possible you broke a tip. You shouldn't check iridiums, just open the box, anti seize them and install.

If they were regular plugs, I don't have any suggestions for you...maybe you just got a bad one. On car engines we used to start it up the engine and pull out the leads one at a time and see if the absence of one of them makes no difference, then you found the bad one. Not sure if that technique works on the boat, never had to try it.

 

[0627Devildog]

I was very gentle with the tightening. I was able to put the drill on the minimum clutch and only speed setting (as opposed to torque). As soon as it was about to touch I would let off and stop as soon as it hit. I would NOT recommend that technique for everyone. As mentioned, if you don't know your drill and your plugs very well, you WILL overtighten.

The thought of that makes me cringe even for an experienced mechanic. . . . . . . The potential for cross thread, over tightening, snapped plug, etc. . . . is just too much for me to even consider that as a viable option. Glad it worked out for you.

 

[txav8r]

It could be a bad plug, or you didn't get the coil seated completely on one of them. I doubt that the amount of torque on the plug is causing any issue today, but these plugs are known to break easily. So many of us use anti-seize on the threads, and are VERY careful when it comes to installing them. Also, you mentioned oil splatter on the air filter...that will cause rough running too, not to mention choking the engine. Try running without the air filter just to see if it makes a difference. But definitely replace it if they have any visible oil on them, because even oil mist will saturate the filter and restrict the air flow. These plugs are FRAGILE, and the best method I have found when using anti-seize on them, is to hand tighten without a wrench to snug, then only 1/4 to 1/2 turn farther, and if they are snug at a 1/4, I don't go farther.

 

[tdonoughue]

I would check the coil seating, but also to see that you didn't pull one of the wires going to the coil when you pulled off the coil. Tight fit on those. If you pulled too far you could pull the other side of the wire.

 

[cbus]

@Cotay Did you ever find out what happened?

 

[Cotay]

@Cotay Did you ever find out what happened?

I removed each plug again, double checked the gaps and then reinstalled. Maybe it was a loose connection or my starboard engine is finicky about gaps, but I opened each of the plugs up just a bit (they were closer to the bottom of the range and now they are just under 0.8) and everything is working fine. I did purchase an inline plug tester that I can use in the future to check for proper spark but I didn't end up needing it this time. All seems well now!

 

[Glassman]

Good Job!
Nice to get it done and out of the way....all the while saving some Benjamin's

I changed mine once while parked at the guest dock in the time it took the waitress to fill our lunch order. If she had screwed it up (again) I was going to do the oil change too.

These boats really are pretty easy to maintain.

 

[maboat]

These boats really are pretty easy to maintain.

That right there is THE BEST FEATURE of these boats, hands down winner above all others!

 

[txav8r]

And chalk another engine issue up to spark plugs...glad you got it fixed!