Mercury Optimax 2.5L V6 DFI Rebuild Part 1

How to rebuild a Mercury Optimax 2.5L V6 DFI Outboard Powerhead

Category:

Autos & Vehicles

Tags:

• Mercury
• Optimax
• 2.5L
• V6
• Rebuild
• Powerhead
• DFI
• Outboard
• Piston
• Rod

[adricist]

As I said earlier, I have put over 150 h on this engine since and it has been running perfectly. I am sure that if we had videos of what happens when most mechanic rebuild engines there would be a lot of wrong things we could comment on! This was my first Outboard rebuild and since then I have done more and they have been all very successful. By the way, I always have workshop manual for the engines I work on.

[adricist]

I did have the Piston in hot water, (almost boiling) but did not try the wrist pin in the freezer. By the way I have just rebuild another 2.5L Optimax Block and in this case the wrist pins went right in by hand without needing any temperature or anything else.

[adricist]

As previously mentioned, I agree with you and I did use a cradle although not clearly visible in the video. And by the way there wasn't much pressure there at all, just enough to make the camera shake on the table and made it feel a lot worse than it really was!

[adricist]

Checked compression yesterday as I have since discovered that I had a failed Coil that had caused an increased fuel consumption at higher RPM and I still have a very even 120 PSI on all 6!

[adricist]

If Mercury had posted a training video it would have saved me doing it! Regardless, your point is a good one and I did not specify in the video what I did. I made a cradle by using a piece of soft wood with a whole in the middle and I also broke it in half in the middle line and joined it together with strong silver plastic tape so that it would stay together but it would also bend in a V domed shape! I have put lots of hours on this engine since the rebuild and it is running very well.

[joeycbr600]

Hit it

[6speeddakota]

the wife must love you building a motor on the kitchen table :)

[KWCONCH420]

@mercguy63 for someone who is talking a lot of shit, i dont see your vids asshole and if you did fuk off any way shit head.. oh and did this guy even say he was certified...you fukin twat

[dragoncustomcycles]

dead blow hammer my friend. my teacher in tech school was in the field for over 30 years. laughed at what it said in the book and showed us the pers and dead blow hammer method. as long as the boss is squire in the hole, it will go in fine, without and stress.

and there is no diffrence betwen a 4 stroke wrist pin and a 2 stroke wrist pin.

[mercguy99]

thats where you seriously wrong!!! By using a press, you maintain a constant and even pressure on the wrist pin boss of the piston and wrist pin. When you "hammer" them in, you create a "bounce back" effect on the wrist pin which can cause undo stress on the wrist pin boss and distort the area and create a fracture area................4 strokes are even more critical.........glad you are not assembling motors for me!!! 22yr Merc certified tech

[dragoncustomcycles]

lol. no your not. i have re-built many, many 2 strokes and 4 strokes. the wrist pins are not special in a merc motor. using a press is the best way but you can hamber them in also.

[BulletBlazerSS]

what is the correct way of heating up a piston?

[mercguy63]

suggest you read the factory service manual very carefully to understand the correct way to rebuild this engine...........you are asking for trouble doing it the way you are instructing.............you are damaging the wrist pin area of te piston by POUNDING the wrist pins in......

hot water is not correct either!