Leaky spark plug holes?

 Hi Team,

My old boy has a early 2000's 70hp Yamaha tractor. Great little motor that has only ever gone full noise three times in its life. He does the PP to Shoalwater run every weekend when the weather is nice to pull pots so it doesnt get much use.

It got serviced by a mobile dude in October but started to run funny a fortnight ago. He took the cowling off and noticed the spark plugs were loose. Loose enough to rattle and undo by hand. He tightened them to just beyond snug.

They took the motor out on the weekend and it ran like shit. Mum suggests running on 1.5 cylinders. It is a two stroke so is naturally noisy. 

They got home and noticed oil is running out of the spark plug holes.

 

He is off to buy new plugs because the ones that were in are heavily carboned up.

 

Is this a problem? 

 


sea-kem's picture

Posts: 15008

Date Joined: 30/11/09

 Sounds like rings Paul.

Mon, 2024-01-29 10:13

 Sounds like rings Paul.

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Swompa's picture

Posts: 3893

Date Joined: 14/10/12

 Not sure what you mean,

Mon, 2024-01-29 10:56

 Not sure what you mean, Andy? 

sea-kem's picture

Posts: 15008

Date Joined: 30/11/09

 If there's oil leaking out

Mon, 2024-01-29 12:23

 If there's oil leaking out through the plug holes and the plugs are clogging up could possibly mean the piston rings are worn. Has it has a compression check?

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Love the West!

Swompa's picture

Posts: 3893

Date Joined: 14/10/12

 Thanks mate. It has numbers

Mon, 2024-01-29 12:52

 Thanks mate. It has numbers written on all cylinders so i guess so. I will check witht he old boy

Faulkner Family's picture

Posts: 18040

Date Joined: 11/03/08

If done up right there should

Mon, 2024-01-29 10:14

If done up right there should not be any leaks at all. Maybe the plugs were over tightened when the service was done and now the thread has been damaged. You could try a bit of locktight on the plugs to see if that stops the leak.

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RUSS and SANDY. A family that fishes together stays together

Posts: 287

Date Joined: 04/08/22

Plug seals

Mon, 2024-01-29 10:53

 Nah don't loctite them in !! Put new plugs in(will come with new seals)if they still leak I'd say the heads cracked through the thread 

Piggy's picture

Posts: 553

Date Joined: 24/08/12

Where are you located?

Tue, 2024-01-30 08:33

 Where are you located mate? I had the same engine for years and pretty much know them inside and out.

Do not under any circumstances put sealant or thread locker on your spark plugs, massive no no.

What is sounds like to me is it could be a simple as the wrong spark plug, if it just got serviced and started happening that is my guess.... More drastic things would be that they have over tightened the plug and threaded it or yeah cracked head. 

I wouldnt worry about the oil too much, they do have a hell of alot of oil that go into them... Im also assuming it still has the VRO connected so it is probably over oiling like buggery anyway... If it is still connected I would strongly recomment disconnecting it and just pre-mixing it yourself in the fuel tank.

Anyway I am in Southern River, if your close by you could bring it around and I can have a look

Cheers

Pig

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I go boating not fishing

Swompa's picture

Posts: 3893

Date Joined: 14/10/12

 Thanks for the offer mate. I

Tue, 2024-01-30 17:26

 Thanks for the offer mate. I am in thornlie...

I think the old boy has calmed down and will try new spark plugs that are done up properly....with the seal kits in place.

Piggy's picture

Posts: 553

Date Joined: 24/08/12

No dramas

Wed, 2024-01-31 07:55

 No dramas, thornile is just down the road if you get stuck

Cheers

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I go boating not fishing