1980 Mercury 70hp Repairs part 1

This is Part 1 of a series on repairs I performed on a 1980 Mercury 70 HP 2-stroke outboard. Much of it is on carburetor removal and synchronization.
Part 2 will be setting the base "Pick-up" timing and max spark advance.
And I will continue with engine running adjustments. This was a long drawn out process to bring this engine back to it's factory running condition.
Hope it helps and Enjoy!

[@davestewart9146]

Really interesting, thanks Ted 👍😁

[@randallhamrick1800]

Hey Ted. Nice info and thanks. Any chance to speak with you or ask about a problem? Real tired of mechanics putting a bandaid but charging full price.

[@tedsmarinerepair8956]

@@randallhamrick1800 sure you can contact me at [e-mail]

[@randallhamrick1800]

OK. Thanks

[@lodollar23]

Never used grease on 1 side of the gasket before. Does that seal ok long term?

[@MrNonsenseakaMarze]

Does anyone know the name of the black plastic adjuster piece that connect the rods to open the throttle at an equal rate?

[@tedsmarinerepair8956]

You can look up your engine via serial # and find the part you need. This is the Mercury online parts link.
www.mercurymarine.com/us/en/parts-and-service/parts-catalog

[@crindac]

Hi ted! I'm from Chile and i have same outboard and the 1st cylinder measures 80 lb/in2 and 2nd and 3rd around 130. What it is tje first thing tja i have to do?

[@tedsmarinerepair8956]

For either a 2 stroke or 4 stroke I would remove the cylinder head for further inspection

[@crindac]

Thanks Ted. I will need more tools 2 bolts were so tied and broke both. I put WD40 but it didnt work.

[@tedsmarinerepair8956]

@@crindac pb blaster or Krill work much better than WD

[@crashtestdummie67]

This model has cylinder block and cylinder head in the same piece so you need to take the whole motor apart. But you can try the foam who can loosen piston rings but it's most likely need a rebuild...

[@crashtestdummie67]

This model overheats and screws the top piston and cylinder....

[@javiermontes3777]

😮