Spark plugs at 10 hours

[Wisewaves]

The manual says to check the plugs at 10 hours. Is there any benefit to changing plugs while I do the oil change?

 

[FX195]

Not much to inspect at such low hours. No benefit in replacing them either. I replace at 100 hour intervals, its peace of mind plus some do rust and can seize on the cylinder head. If you decide to inspect you can spray a little WD40 onto the spark plug to minimize any exterior rust.

 

[suke]

I was of the mindset to at least give them a look over. Shortly thereafter I developed a hot start issue on my port motor. I replaced the spark plugs and gapped them really close to the low end of the acceptable range for our motors. Hot start issue is now gone. The issue didn't start until after I pulled the plugs and checked them. Although that was likely a coincidence. What I mean by all this rambling.....if you're going to pull them to check them you might as well replace them. Otherwise, I say let it ride.

 

[HangOutdoors]

I replaced mine which I probably didn't have to do, but I was trying to track down some low RPM's I was seeing.. I noticed that the gaps were off on two of them, just a bit bigger than the spec. Not sure if that is an assembly line thing, etc. If you are going to inspect them run a gap gauge on them just to double check and verify would be my suggestion.

 

[Canuckjetboater]

Checked mine at 10 hours seemed a little dark as if the engine was running a bit rich. Engine runs very smooth. Left plugs in - will replace later in summer if enough hours or at fall haul-out. My manual does not call for the oil filter to be changed at 10 hours. Who wouldn't do that - the Yamaha oil kit comes with one anyway. I also bought two oil filters......will spin one off in July and top-up the engine and spin one off in August and top off the oil. Haul out for me will be September/October.

 

[Wisewaves]

Thanks guys!

 

[Daren and Heather]

The spark plugs were so cheap ($23 for all 6 of them), that I decided to just buy them up front, that way I could replace them right then and there if I found anything wrong.

Then I decided it would be more efficient, if I just checked the new plugs/adjusted the gap inside the comfort of my house, and then just replaced them when I was in the boat pulling the old plugs. Again, only $23... so it was easier to just replace with the new ones.

 

[Matt Phillips]

I change mine out every year. If you don't change them, keep the spares on the boat in case you need to. it doesn't take long. One tip though is buy yourself a magnetic spark plug socket....cheap on amazon...it'll keep the thing firmly in place when you're lowering them into the holes.

 

[212s]

The manual says to check the plugs at 10 hours. Is there any benefit to changing plugs while I do the oil change?

Funny, my manual says to check them at 10 hours to verify proper operation, not replace. Even the oil filter doesn't require a change until 100 hours per the manual. But if you're doing the oil with the kit, the filters are part of the kit so might as well. My dealer changed oil and filters which I asked for at the first service to help remove any debris.

I intend to change plugs with the oil and filter yearly though...they're not expensive.

 

[Matt Phillips]

Interesting as I don't recall changing the air filters. I guess I should check the manual for that interval. Unless you're operating in a smoky area, the marine environment is generally pretty dust free so those things can go a long time.

 

[212s]

I change mine out every year. If you don't change them, keep the spares on the boat in case you need to. it doesn't take long. One tip though is buy yourself a magnetic spark plug socket....cheap on amazon...it'll keep the thing firmly in place when you're lowering them into the holes.

Do you know how long of a socket or extension is needed to reach the plugs?

 

[212s]

Interesting as I don't recall changing the air filters. I guess I should check the manual for that interval. Unless you're operating in a smoky area, the marine environment is generally pretty dust free so those things can go a long time.

Inspect at 100 hours in my manual. As you say, no need to change them often unless you're in an area sucking up lots of dust, pollen or similar.

 

[Matt Phillips]

Use a regular spark plug socket. A 6” extension will do it. I also use a t-handle rather than a wrench...that way I can tell how tight the plugs are getting.

 

[212s]

Use a regular spark plug socket. A 6” extension will do it. I also use a t-handle rather than a wrench...that way I can tell how tight the plugs are getting.

Ok so normal then - I do something similar, where I hold the ratchet at the head in my palm so I can feel it there's any tension when installing critical parts. I also spin the plugs backwards and feel for the plug to "drop" into the threads to prevent cross-threading...my father taught me that trick when I was a kid for any sensitive screw-in items.

 

[212s]

Checked mine at 10 hours seemed a little dark as if the engine was running a bit rich.

That seems normal for fuel injected engines, rich at idle to stay cooler and then lean out the curve as the revs climb.

Engine runs very smooth. Left plugs in - will replace later in summer if enough hours or at fall haul-out. My manual does not call for the oil filter to be changed at 10 hours. Who wouldn't do that - the Yamaha oil kit comes with one anyway. I also bought two oil filters......will spin one off in July and top-up the engine and spin one off in August and top off the oil. Haul out for me will be September/October.

Hmm...interesting idea to change the filters a couple of times but I think a magnetic drain plug will catch more debris than the filter. Not sure if these engines have drain plugs...?

 

[Canuckjetboater]

Funny, my manual says to check them at 10 hours to verify proper operation, not replace. Even the oil filter doesn't require a change until 100 hours per the manual. But if you're doing the oil with the kit, the filters are part of the kit so might as well. My dealer changed oil and filters which I asked for at the first service to help remove any debris.

I intend to change plugs with the oil and filter yearly though...they're not expensive.

That seems normal for fuel injected engines, rich at idle to stay cooler and then lean out the curve as the revs climb.

Hmm...interesting idea to change the filters a couple of times but I think a magnetic drain plug will catch more debris than the filter. Not sure if these engines have drain plugs...?

@212s .....the spin the filters off - top-up oil, is an old trick of guys who run their engines up (fast) - or work them hard (slalom ski/tube). After some hard use or between changes I spin the filter off, I used to clean the engine mating surface with a non-shed cloth, put oil on the new filter gasket, fill the new filter with oil, install it, (the engine is already hot as I heated it to operating temperature before I removed the "old" filter) - crank it to distribute the oil, take a dip stick reading, add oil as required, check oil and voila. Do this and your engine will last forever. The old filter removes contaminates the new oil refreshes. Learned this years ago from a renowned engine builder.

 

[WetWillie]

I agree with most here pulled at 10hrs checked gaps put them right back in no issues will change them if I ever get to 100hrs

 

[212s]

I agree with most here pulled at 10hrs checked gaps put them right back in no issues will change them if I ever get to 100hrs

"Ever get to 100"???
I find that offensive!