Broken off Spark Plug into cylinder head

[FSH 210 Sport]

Just checked the service manual for the TR-1 engines, mine shows 9.6 ft lbs.

Do the plugs that the 1.8L engines use have a crush washer or is it a V shaped bottom that seats into the head? I did a quick search and I see that the Yamaha outboards at least the one I found showed 18ft lbs for the spark plug which to me seems like a lot for a spark plug.

reading down one of the posts about Yamaha outboards a guy posted this from his Yamaha outboard service manual. You will notice no mention of using less torque when antiseize Is applied.. boom.

 

[Neutron]

spec is 18.4 on the 1.8s. Crazy to me it’s half on the MR1

That is very strange, would think they would be close

 

[Neutron]

Just checked the service manual for the TR-1 engines, mine shows 9.6 ft lbs.

Do the plugs that the 1.8L engines use have a crush washer or is it a V shaped bottom that seats into the head? I did a quick search and I see that the Yamaha outboards at least the one I found showed 18ft lbs for the spark plug which to me seems like a lot for a spark plug.

It has a crush washer

 

[lazergeek]

spec is 18.4 on the 1.8s. Crazy to me it’s half on the MR1

Steel heads vs aluminum? I don't know what the 1.8 has?

 

[Neutron]

Steel heads vs aluminum? I don't know what the 1.8 has?

Aluminum on both

 

[lazergeek]

Aluminum on both

One of life's mysteries then.

I'm going to stick with 1/2 turn after finger tight like NGK recommeds, but I also use anti seize too.. It's been working for me for 30 years on my Jet Skis and boat.

 

[FSH 210 Sport]

So the goal is to keep the plugs from seizing in the head in a marine environment, anti seize is the only way to assure that.

Its a lot like using ethanol laced gasoline without treating it, it will be fine until it isn’t, and when it isn’t it is exceptionally bad, and you will either be kicking yourself because you didn’t treat it or because you didn’t want to pay a little extra to get non ethanol fuel when it is available to you.

It sounds like the best way is to use the 1/2 turn method after the crush washer comes in contact with the head for those who are concerned about anti seize causing over torquing.. then you get to have your cake and eat it to!

Here is the big pay off, by putting a thin coat of anti seize on the plug threads or treating gasoline properly you save the most precious commodity, time. You can never replace the time you loose on the water because of mechanical issues.

 

[drewkaree]

This seems really low, IIRC it’s 18.5ft/lb.

While I'm confident YOU will look for it, or at least you know where to look, this is what confounds me, when folks ask on here about the numbers instead of going to the manual. It can easily be found online if it's been lost too, so that's not a good rationale.

Given the info about the service manual and everything else in this saga, that's about all I'm gonna point out for others - your owners manual and the service manuals are there for a reason. Find them, keep them handy, and then USE them for basic info like this instead of trusting our memories.

I have a hard enough time with remembering to leave the house with pants on, don't trust my torque values! ?

I wouldn't hesitate to pick @adrianp89's brain about audio stuff, but even then, I'd verify and/or do my own homework to add confidence or clarify the process if I could find photo help for an assist

 

[adrianp89]

While I'm confident YOU will look for it, or at least you know where to look, this is what confounds me, when folks ask on here about the numbers instead of going to the manual. It can easily be found online if it's been lost too, so that's not a good rationale.

Given the info about the service manual and everything else in this saga, that's about all I'm gonna point out for others - your owners manual and the service manuals are there for a reason. Find them, keep them handy, and then USE them for basic info like this instead of trusting our memories.

I have a hard enough time with remembering to leave the house with pants on, don't trust my torque values! ?

I wouldn't hesitate to pick @adrianp89's brain about audio stuff, but even then, I'd verify and/or do my own homework to add confidence or clarify the process if I could find photo help for an assist

I literally look it up every time just to double check the values lol

 

[Maslin]

Steel heads vs aluminum? I don't know what the 1.8 has?

Mercedes spark plugs have been 23 nm for a long time, all aluminum heads. ~17 foot pounds. No boat engines of course

9 seems extremely low, that's like hand tight. 23 nm isn't very much.

 

[scokill]

Mercedes spark plugs have been 23 nm for a long time, all aluminum heads. ~17 foot pounds. No boat engines of course

9 seems extremely low, that's like hand tight. 23 nm isn't very much.

It's definitely not hand tight.