Check the gap on your spark plugs!

I was finally able to get my boat ready for the season this past Saturday, did the oil change and spark plugs. I'm so glad I did this. keep in mind I'm the second owner on the the 232 "all" service related maintenance were done by a pretty reputable Yamaha dealer, I even have a copy of the invoice that shows what was done and to think last owner payed $489.62 for this half a$$ job!

First thing I noticed none of the spark plugs were gapped correctly, there were couple of plugs that were set below .010 inches, there was no signs of anti-seize used, and the biggest heart stopper was when I pulled the 3rd plug out of the starboard engine I only pull the plug!! No threaded end....

So after calming down and getting couple (alcoholic) drinks in my system, started to think.... how can I get this broken treated part of of the head with out pulling the motor? So couple hours later though about using a easy-out (screw extractor) and boy I tell you when I saw that broken threaded part come out it was like lifting a ton of bricks of my back! I wish I would of taken pictures I was so upset at first then joyful I dint think about pictures.

Anyways guys be sure to check the gap on your spark plugs, I always thought these MR1's ran rough. After new plugs gapped correctly these engines now purr and what a difference on performance!! If feel I have a new boat again.

Couple of pics from yesterday in lake Conroe.

The number three plug is a common issue. You are very lucky to have gotten it out!

Very lucky indeed! It is the very reason most of us throw out the torque wrench, apply anti-seize to the threads, and do the finger tight and then 1/4 to 1/2 turn and STOP! I would also recommend annual plug changes for the same reason. Good looking boat btw!

It's the reason I change plugs every year and it's cheap (as well as oil change at beginning of season and towards the end). I also just use the CR9eb instead of eix (iridium) I don't want extended use of them sitting in the head. I'm not good at the 1/4 to 1/2 turn and do use a torque wrench that has in/lbs. I've settled for adjusted torque with anti-sieze of about 90 in/lbs.

Crlos16 said:

... and the biggest heart stopper was when I pulled the 3rd plug out of the starboard engine I only pull the plug!! No threaded end....

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@Crlos16 I hear you...the one downside to how much time I spend on the forum is that I am in constant fear of every bad thing I've read about happening to my boat. I am typically sweating with fear whenever I get to the #3 plug, I'm just waiting for my engine to crack, I keep looking for water in my oil, I never expect it to start when I turn the keys, I keep looking for my engine compartment to fill with water, at any moment I know that my impellers are going to seize up because I just sucked up a golf ball, and to top it all off, my wife's sister - who was late - is going to spill red wine!

For various reasons (my fault) I wasn't able to change my plugs out at the beginning of this season. Boat is now in the water so I'm leaving them until the end of the season just so I can avoid running into that issue with the boat in the slip. Fingers crossed!

@Scuba_ref very funny ... the forum educates me and also causes FOMO ... Fear Of Major Overhaul. I am way in the plus side for what this forum has done for my improved boating experience ... but we need to remember the forum focuses on helping members out with boating maladies.

Would be a boring forum if all the threads were like my last experience "boat ran great, bilge worked, batteries held up, cooked warm food on my grill mod and my box-anchor held firm in strong tides" ... no villains, no suspense ;-)

Now that I think about it, I was thinking to myself I can't believe people pay that much for an oil change and spark plugs! This was maybe a 45min job tops. Man I tell you guys that feeling you get when you only pull half of a plug! First Then 2 hours later

This time I used anti-seize, gapped the plugs at .028inch, hand tight them plus a 1/4 turn, I think one motor was only running on 3 cylinders cause of the broken plug. What a difference, I'm still shocked on how smooth and how much power it has out of the hole.

There was residue on the threads for the spark plug assembly screws when I checked them during 10 hour service. Are you guys using anti-seize on those as well?

When I bought my boat used I did the plug change and got them all out, but a couple of them I thought were going to break, when I installed the new plugs I used a light amount of anti-seize on them. I do plugs each year, have a new set I need to install for this season.

With anti-seize on my plugs stay in for years. Iridiums though. Cam.

I didn't do a good job asking that question. I'm referring to the 2 spark plug cap screws at each plug. Mine looked like someone had put antiseize on them and I was wondering if that is common?

I think they come from the factory with some kind of thread sealant on them. I don't replace it when I change the spark plugs.

Stevenpigsooie said:

I didn't do a good job asking that question. I'm referring to the 2 spark plug cap screws at each plug. Mine looked like someone had put antiseize on them and I was wondering if that is common?

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No need to add any anti seize to the cap screws, they do not seize and they are not torqued very tight, nor do they seem to get loose. It is the dissimilar metals and the exhaust moisture that causes the number three cylinder spark plug to be such a possible problem, along with the required spark plug being a tad weak and breakable.

Totally off subject, @Crlos16, I like your tower, did you install it or did the first owner. I was thinking about doing the same thing to my 232.

@islandstyle57 That's from factory, if I'm not mistaken all limited S came with this tower.