3YM30 exhaust elbow gasket

[cliveshelton]

Yes I know! sorry.
I have removed the elbow (it's been weeping for a while) and it appears to be cracked at the weld.
I have ordered a SS replacement from the recommended guy in the usa.
My question is about fitting the new one.
Under the old gasket is a quite thick layer of soft stuff (graphite, lead?). Is that part of the old gasket? It doesn't appear to be salt deposit. I started scraping it off and thought I would ask before going any further.
Should I remove it? What tool should I use for that? How much to remove? Or does the new gasket (not ordered yet) seal everything when nipped up?
Thanks for any suggestions. Photo here

View attachment 49146

 

[Cloven]

Scrape off all the soft stuff, its part of the old gasket. You need to get back to bare metal on both surfaces - engine & new exhaust elbow.

 

[cliveshelton]

Thanks. What should I use? File? Screwdriver blade? Stanley knife?
is it recommended to use gasket sealant? Which one?

 

[Spyro]

Just fitting a new one to my 2gm20. I removed all the old gasket with a 1 inch chisel. The new gasket compresses quite a bit. No sealant required

 

[Interlude]

May I ask how old is the engine and how many hours has it clocked up?

 

[Spyro]

May I ask how old is the engine and how many hours has it clocked up?

Do you mean mine or the OP? Mine is 28 years old. But it wasn't the original ehaust elbow. previous owner replaced it less than 10 years ago along with a complete new cylinder head becaus his old one failed.. I've had the boat 6 years

 

[cliveshelton]

May I ask how old is the engine and how many hours has it clocked up?

My 3YM30 is 2007. Hours approximately 400. She was not used between 2008 and 2011.
Still waiting for the delivery of the SS elbow from the USA. Apparently its in the UK but I suspect it is held up in customs. I'm in no hurry fortunately.

 

[Spyro]

My 3YM30 is 2007. Hours approximately 400. She was not used between 2008 and 2011.
Still waiting for the delivery of the SS elbow from the USA. Apparently its in the UK but I suspect it is held up in customs. I'm in no hurry fortunately.

I received a new elbow from The states recently. I got a card from the postie saying I had to collect it at the post office and pay the customs fee of £3.80, and the kind post office people wanted a £8 handling charge.

 

[charles_reed]

I received a new elbow from The states recently. I got a card from the postie saying I had to collect it at the post office and pay the customs fee of £3.80, and the kind post office people wanted a £8 handling charge.

I just imported one from the States via USP - suggested it was described as a "sample" - it arrived in 5 days and cost nothing more.

If the imported object has a putative value, customs dues and VAT have to be paid, by the importer to HMC.

 

[cliveshelton]

Elbow has arrived. No duty!
Can anyone help with a source and part number for the gasket I need? 3YM30.
Cheers

 

[30boat]

Elbow has arrived. No duty!
Can anyone help with a source and part number for the gasket I need? 3YM30.
Cheers

I make my exhaust gaskets in a graphite asbestos material that I have lying around.Cheap and effective.

 

[Cloven]

Elbow has arrived. No duty!
Can anyone help with a source and part number for the gasket I need? 3YM30.
Cheers

Here it is

http://www.marine-power.co.uk/index.php?route=product/product&path=20_192_111&product_id=234

i would recommend getting 2 or 3 as each time you remove the elbow to check it (and you can't check it wothout removing it) you will need a new gasket.

 

[cliveshelton]

[COLOR=rgba(0, 0, 0, 0.701961)]I can't believe that a simple gasket is going to seal the pitted surface of the exhaust manifold. I have taken a better photo to show the damage. Or am I worrying too much and should just refit it with the yanmar gasket. Perhaps some sort of liquid gasket is best to try? Which one? Or do I need the surface reground somehow?[/COLOR]View attachment 49618

 

[Spyro]

[COLOR=rgba(0, 0, 0, 0.701961)]I can't believe that a simple gasket is going to seal the pitted surface of the exhaust manifold. I have taken a better photo to show the damage. Or am I worrying too much and should just refit it with the yanmar gasket. Perhaps some sort of liquid gasket is best to try? Which one? Or do I need the surface reground somehow?[/COLOR]View attachment 49618

That's a bit of a mess, the studs don't look great either. If that manifold is on a plate that could be romoved I'd think about getting it reground. Trouble is how far does the pittting go and would you then need the other faces reground that you have exposed. I'd be tempted to try Some type of high temp gasket sealant. There are loads available in auto shops.

 

[30boat]

[COLOR=rgba(0, 0, 0, 0.701961)]I can't believe that a simple gasket is going to seal the pitted surface of the exhaust manifold. I have taken a better photo to show the damage. Or am I worrying too much and should just refit it with the yanmar gasket. Perhaps some sort of liquid gasket is best to try? Which one? Or do I need the surface reground somehow?[/COLOR]View attachment 49618

That doesn't look good but a good quality silicone gasket sealant will probably deal with it.You'd be surprised the amount of heat it can take.It's used on aircooled motorcycle exhausts and it doesn't get much hotter than that ehausts wise.