TMD, Footer Here... pistons in '79 200 Merc have 0.020 stamped in to the top of

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• Sep 18, 2003

• #1

Does this mean that these are twenty thou over pistons in this 200 and the p/h has been over bored already? If so, how much more can you take down the cylinder sleeves before you, A: run into cooling problems, or B: run out of piston/oversize ring options. Can I at least pray that I might be able to take down another <br />10 thou and find piston/ring options that won't cost me my best friend's wife? Your thoughts are gold! <br /><br />Footer

 

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andrewkafp

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• Sep 18, 2003

• #2

Re: TMD, Footer Here... pistons in '79 200 Merc have 0.020 stamped in to the to

Re: TMD, Footer Here... pistons in '79 200 Merc have 0.020 stamped in to the to

"Best friend's wife" Are you keeping something from us.. Footer ?

 

T

The Marine Doctor

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• Sep 18, 2003

• #3

Re: TMD, Footer Here... pistons in '79 200 Merc have 0.020 stamped in to the to

Re: TMD, Footer Here... pistons in '79 200 Merc have 0.020 stamped in to the to

.020 Does mean it has been oversized.<br /><br />I think .030 is as high as you can go with Factory Pistons. You might check here at Iboats to see if anyone has aftermarket pistons that would be larger.<br /><br />TMD

 

OBJ

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• Sep 18, 2003

• #4

Re: TMD, Footer Here... pistons in '79 200 Merc have 0.020 stamped in to the to

Re: TMD, Footer Here... pistons in '79 200 Merc have 0.020 stamped in to the to

Footer....I'll probably be sticking my foot in my mouth, but, I think the .020 means it has been bored over already. Don't know for sure but I think you can go up to .040 on overbore. Mayebe the Doc will be by and set us (me) straight on the overbore.

 

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The Marine Doctor

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• Sep 18, 2003

• #5

Re: TMD, Footer Here... pistons in '79 200 Merc have 0.020 stamped in to the to

Re: TMD, Footer Here... pistons in '79 200 Merc have 0.020 stamped in to the to

With serial number I would be able to find out for sure if Mercury can still supply oversize or not.<br /><br />TMD

 

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• Sep 18, 2003

• #6

Re: TMD, Footer Here... pistons in '79 200 Merc have 0.020 stamped in to the to

Re: TMD, Footer Here... pistons in '79 200 Merc have 0.020 stamped in to the to

Thanks allot guys, I figured that the twenty thou did mean that it had been punched out already. TDM, are you telling me that I can use stock 200 pistons and go up to 30 thou larger on rings only, or do I need to look at 30 over pistons? I understand this is just advice, and I take it as such..<br />Unicorn, have you seen my friends wife?! As you'd say down in Auz, she's a bikini clad, water skiing SHEILA!<br />OB/Jim, it'd be nice to think I could take another 20 thou off, just to make sure that any light scoring on the cylinder wall is eliminated.<br />Gonna see if I can post you boys the digital pictures that I took (after a sympathy beer) of the cylinder/piston and another of the head.... <br />Share my pain mates!<br /><br />Footer

 

T

The Marine Doctor

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• Sep 18, 2003

• #7

Re: TMD, Footer Here... pistons in '79 200 Merc have 0.020 stamped in to the to

Re: TMD, Footer Here... pistons in '79 200 Merc have 0.020 stamped in to the to

You will have to bore the cyl's oversize to .030 replacing the pistons and rings.<br /><br />TMD

 

T

The Marine Doctor

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• Sep 18, 2003

• #8

Re: TMD, Footer Here... pistons in '79 200 Merc have 0.020 stamped in to the to

Re: TMD, Footer Here... pistons in '79 200 Merc have 0.020 stamped in to the to

I just looked up the pistons for your engine..1979..oversize are NLA<br /><br />Depending on the design of the cylinder head you have...a new one is available.<br /><br />TMD

 

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• Sep 18, 2003

• #9

Re: TMD, Footer Here... pistons in '79 200 Merc have 0.020 stamped in to the to

Re: TMD, Footer Here... pistons in '79 200 Merc have 0.020 stamped in to the to

In my best Tim the toolman Taylor impression:<br /><br />Oh - no..... all six of them @ $300 a piece..<br /><br />Hope that crank con rod journal isn't damaged or I'm gonna have some used 200 Merc parts available!<br /><br />Anybody want a real nice 18.5 ft Sidewinder in good shape - no motor - Hahahahahaha....

 

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The Marine Doctor

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• Sep 18, 2003

• #10

Re: TMD, Footer Here... pistons in '79 200 Merc have 0.020 stamped in to the to

Re: TMD, Footer Here... pistons in '79 200 Merc have 0.020 stamped in to the to

Have you checked for aftermarket?<br /><br />TMD

 

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• Sep 18, 2003

• #11

Re: TMD, Footer Here... pistons in '79 200 Merc have 0.020 stamped in to the to

Re: TMD, Footer Here... pistons in '79 200 Merc have 0.020 stamped in to the to

Not yet Doc. And, I know the rules of this forum, so I'm not even going to ask... I need to research aftermarket, and right now, have no clue where to look. But, I'm sure with some looking I'll get something hooked up..<br /><br />You guys have been awesome, cheers! I'm on my way to Kelowna tomorrow morning to ski, socialize and bring my broken boat home (thank goodness for friends with boats that work) I'm sure I'll be asking some more questions next week as things come apart (literally).<br />But for now.... The water calls, and it's beginning to cool down... Gotta get it while it's here... To boat guys everywhere, THANKS! <br /><br />FOOTER

 

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• Sep 18, 2003

• #12

Re: TMD, Footer Here... pistons in '79 200 Merc have 0.020 stamped in to the to

Re: TMD, Footer Here... pistons in '79 200 Merc have 0.020 stamped in to the to

gosh, I know the sn by heart now...<br /><br />1979 200 Merc B/M <br /><br />SN 5014582

 

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andrewkafp

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• Sep 18, 2003

• #13

Re: TMD, Footer Here... pistons in '79 200 Merc have 0.020 stamped in to the to

Re: TMD, Footer Here... pistons in '79 200 Merc have 0.020 stamped in to the to

Heyy... Footer<br /><br />Fair go mate !!! <br />We don't have "Sheila's" here <br />We only have fair dinkum boatin' babes... who do all the mechanical work, while we sit around drinkin' "Stubbies"..