Merc 402 40hp?

[user 20022]

Awesome thanks! Anyone know if there is a benefit of running forged pistons in a outboard?

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[user 20022]

Ugh!!! So neither cylinder has any scoring. Both are smooth as silk. BUT the bottom cylinder has dimples in it...ugh! Should i be worried? See pics.

If you remember the top piston had scoring and low compression. The bottom had 120psi.

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[user 20022]

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[user 20022]

Well I spoke with my outboard shop and he says he can repair the damage by welding and smoothing it back to shape. I'll go that route if the block doesn't need sleeves.

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[onthewater102]

Detonation damage.

 

[user 20022]

Yep the wot timing looked like it had been tampered with by the P.O. I figure since the top cylinder was not firing the po tried to advance the timing thinking it would help. But it just messed things up bad.

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[onthewater102]

Odd that it occurs in one cylinder and not the other.

 

[user 20022]

The other cylinder wasn't firing. At least that's what the plugs look like.

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[onthewater102]

Sounds like you've got an electrical issue there too - did that motor have a switchbox on it or was it earlier than that?

 

[user 20022]

Oh yea the stator is toast. I'll take pics when I get home. The wires were toast. Both ignition coils check out good. But the wiring to them was also toast hints the no firing ugh. I'll be so happy once this thing is fixed up

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[user 20022]

This is what I found under electricians tape. The ignition coil wires were the same.

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[onthewater102]

A clue!

 

[user 20022]

[emoji17]

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[onthewater102]

Any progress? Or did the electrical issues put the financial nail in the coffin on this project?

https://www.boats.net/parts/search/Merc/Mercury/1973/1402223/FLYWHEEL%2C%20IGNITION%20COIL%20AND%20SWITCH%20BOX/parts.html

is that your motor? if so there is a stator listed as part #5255 in the diagram as component #9 which appears to be miss-listed for $7.29.

 

[user 20022]

Yea this merc has it me beat. The reed block is trashed which means it needs upper and lower bearings, stator cheapest i found is 168 before ship. Shop fees $150, power head rebuild kit 300... I'm gonna just trash this one and find me an OMC of some sort. I could replace all those things and still not have a reliable motor...ugh

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[DaleH]

Yea this merc has it me beat. The reed block is trashed which means it needs upper and lower bearings, stator cheapest i found is 168 before ship. Shop fees $150, power head rebuild kit 300... I'm gonna just trash this one and find me an OMC of some sort. I could replace all those things and still not have a reliable motor...ugh

Ouch ... sorry to hear that ...

 

[user 20022]

No worries man... Just more time off the water and more time to paint the boat.

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[user 20022]

Lesson learned...

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