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**erniefish** · 06-03-2016, 08:06 AM

Originally posted by mailman1 View Post

I am going to replace my port side 2005 250 4 stroke Yamaha power unit. It seized up and when I finally got it loose it has a terrible banging coming from the starboard lower side of the power head.
I have generations of mechanics in my family and have rebuilt several automobile engines so I am pretty confident that I can at least buy a rebuilt power head with a warranty FOR SURE!!! and replace like for like???? Any advise on the best way to do this??? I have an commercial engine lift, impact tools and a "MUST" save money to get this done.

I have pulled the power heads on my 2004 f225 a few times ( oil pumps , a shift shaft ) pay a little attention to rigging proper lifting harness, the bolts on the rear of the motor are a pia . Very doable ,good luck

**mailman1** · 06-03-2016, 08:54 AM

Thanks erniefish!!!!

I was hoping to see an answer like yours!!!! Do you know of any repair manuals that might lead me step by step????
mailman1

**ausnoelm** · 06-03-2016, 05:43 PM

What exactly is a "port side power unit"? Buy a genuine repair manual.

**boscoe99** · 06-03-2016, 05:59 PM

Port side power unit is what we sometimes call the left hand motor's power head (or power plant) here up over.

Generally one of two. But some times one of three or four.

I second the buy a genuine repair manual comment but unfortunately Yamaha creates data for a trained Yamaha mechanic. It is not very good for someone that is not familiar with removing power plants.

If I were the OP I would get a Mercury Marine service manual for their version of the Yamaha F225. Much more detailed information, most of which will be applicable to an F250.

**ausnoelm** · 06-03-2016, 06:27 PM

OK, pretty simple, it kind of seemed to me he was trying to remove a part (power unit) off the port side of the motor, in fact he simply means the entire power head off the port side engine! I know it seems obvious (now) but sometimes when reading things, your mind interprets things completely different to what others do, or how the writer intended, terminology can confuse issues, like the old, crank, turnover, start, run thing.

**formula29** · 06-03-2016, 08:22 PM

You should be fine, I like to take a few pictures all around the engine just so I can get all of the wire harness and hoses back in the proper spots, since you have twins no need for that, I did an f300 a while back and not a big deal at all, I had the Yamaha manual and did need to read through it well, one thing that almost got me was just skimming through to get the head torque, there were two torque values I was just looking for the numbers,, first step say 30 pounds then second 75, I almost missed the third step, it was an additional 90 degrees or so, the only reason I caught it was I remembered it being much harder to loosen the head bolts than to torque them back down.so I went back and read the whole procedure, other than that its just a 4 stroke to me, and make sure all the timing marks are lined up and don't rotate the camshafts once the belt is off, the valves can hit the piston.

**boscoe99** · 06-03-2016, 09:12 PM

Originally posted by ausnoelm View Post

OK, pretty simple, it kind of seemed to me he was trying to remove a part (power unit) off the port side of the motor, in fact he simply means the entire power head off the port side engine! I know it seems obvious (now) but sometimes when reading things, your mind interprets things completely different to what others do, or how the writer intended, terminology can confuse issues, like the old, crank, turnover, start, run thing.

I am only guessing that he wants to replace the power head.

Languages and meanings can be tough.

My wife speaks in riddles. Hell if I know what it is that she wants half the time she wants something done.

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