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Just change the plugs!

cwoav8r

Jetboaters Captain
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Location
Naples, Florida
Boat Make
Yamaha
Year
2008
Boat Model
AR
Boat Length
23
So, yea, long time no sea... work has been getting in the way of my personal life for way to long, and severely interfering in my water time. Even though, every time we have had a chance to get out on the boat (read... like four times a year) I have had no issues with the boat at all until last month. (last trip was a month prior with no issues at all)

Launch the boat, make the agonizing 20 minute no wake trip, and firewall the throttles.... the right engine will only make 7k. I thought maybe it would clear up after a little warm up... but no. At cruise the throttles were split more than an inch and a half to keep them both at 7k, the right one would just not go any more. First thought was maybe the cable slipped. Opened it up, and sure enough there was a bit of slack... took it out, but with no change. Why I tried this next I don't know, but every other time I tried full throttle in reverse the right one would make 10k... As I suffered a swollen impeller housing due to corrosion on the left pump a several years ago, I thought this might be the case. At any rate, we were able to enjoy the rest of the day, and I knew when I got home I could log on here and find the answer.

Folks, when I searched for an answer here I found a ton of posts relative to my problem and the majority were about spark plugs. In those threads were doubts about whether or not the plugs could really be the problem... JUST CHANGE THE PLUGS! Next trip with new plugs in hand... 10 minute job and I immediately noticed the RPM change after starting at idle. As soon as we made it out of the zone, 10.5k on the problem engine... YES. 10k all day both sides...

And on that note, in reference to the anti-seize debate... (and I am ashamed to admit it had been a little over four years since they were changed) my Iridiums without anti-seize turned right out, no problem. Just warm up the engine before you do a plug change and it should all work out fine. Oh yea, if there was even a question about the NGK Iridium (CR9EIX) plugs in the MR1s, they last about 4.5 years... ;-)

So, just to add... the MR1s are pretty much bullet proof for those looking to invest in a boat (or jet ski) so equipped. I have never been happier, and never spent so little (with respect to engine maintenance) on my AR-230.

Oh Yea... New steering wheel for Christmas!!!

20191201_143236.jpg

Guys, Happy "belated" New Year! I hope to get a little more active in the near future...

Cheers!
Ed
 

Gym

Jetboaters Admiral
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Location
Falmouth, MA (Cape Cod)
Boat Make
Yamaha
Year
2006
Boat Model
SX
Boat Length
23
Glad it worked out @cwoav8r. Been awhile since hearing from you. Glad you're still onboard. As an MR-1 owner for the last 11 years I can attest to the spark plug theory. I've migrated from annual to once every two year changes with no I'll effects. When I do swap them out I keep the old, good set in the glove box as an emergency spare.
 

Cleveland Steamer

Jetboaters Commander
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Location
Cedarburg, WI
Boat Make
Yamaha
Year
2018
Boat Model
AR
Boat Length
24
I always had confidence in changing plugs... However, several years ago I did a plug change and developed a misfire. Couldn’t figure it out. Ended up taking it to a dealership and several hundreds of dollars later they determined one (1) of the new plugs were bad.. 😕 Most expens plug changes I ever made.
 

jtwrace

Jet Boat Lover
Messages
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Location
Orlando, FL
Boat Make
Yamaha
Year
2019
Boat Model
Other
Boat Length
PWC
NGK plugs do NOT require anti-seize. Further, the use of it will have a great affect of torque that you're applying and could damage the threads.

NGK spark plugs feature what is known as trivalent plating. This silver- or chrome-colored finish on the threads is designed to provide corrosion resistance against moisture and chemicals. The coating also acts as a release agent during spark plug removal. NGK spark plugs are installed at the factory dry, without the use of anti-seize. NGK tech support has received a number of tech calls from installers who have over-tightened spark plugs because of the use of anti-seize. Anti-seize compound can act as a lubricant altering torque values up to 20 percent, increasing the risk of spark plug thread breakage.
 

Zeusmotorworks

Jet Boat Junkie
Messages
301
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Location
Republic of Texas
Boat Make
Yamaha
Year
2019
Boat Model
FSH Deluxe
Boat Length
21
Come from aerospace manufacturing, owned business with rally builds (in house engine), and over 30 years turning wrenches. No one will ever show me an instance where anti-seize itself caused a failure, problem, issue, nor convince me its a bad idea to use on most common spark plugs. Have almost exclusively used NGK during that time. What I WILL tell you is any monkey with a wrench CAN cause problems over torquing with or WITHOUT anti-seize. I've actually seen more with the latter cause the majority of these people didn't even know what the stuff was in the first place. They just knew "if tight is good, tighter is better", and always use a bigger wrench or hammer.

Oh, and HAVE seen properly torqued NGK plugs seize over the years. Not often by any stretch, but has happened. So for me it's an ounce of prevention.
 

jtwrace

Jet Boat Lover
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Location
Orlando, FL
Boat Make
Yamaha
Year
2019
Boat Model
Other
Boat Length
PWC
Yeah, I was part of many teams and manufacturers in the racing industry so I've seen my share too.
 
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