2004 Mercury 75 HP 4 cycle reliability

[fisher972002]

All,
I know these engine's haven't been around all that long, but does anybody have any advice on reliabality and experiences or things I should look for. Looking at a used boat with this motor.

I have 2 sides of the coin. My Dad has a 1999 150 optimax and it was a piece of junk motor, we hated that motor, only used a few times a year and always broke down..
My buddy has a 201 75 HP mercury 4 stroke and it is a really nice running, been reliable so far motor powerplant...

Just wondering if the 2004 motors are good, I've had good luck with the 79 Johnson 55 and 89 90 HP Evy on my other boats, but don't know much about the newer merc 4 cycles other than the one my buddy has which I thought was really nice...

Thanks

 

[DRIFTER_016]

Re: 2004 Mercury 75 HP 4 cycle reliability

I can't tell you about the 75 but at the fishing lodge in the NWT I have been working at for the last 15 years we have a good number of 30 horse 4 stroke Mercury's and they are very reliable. So reliable that we no longer run kickers on our boats. The only issue I have seen with these motors in the 5 or 6 years we have been running them is the tilt assist cylinder has needed to be replaced on 2 or 3 of them. The 75 should have power trim and tilt and thus will not have this cylinder.

 

[jhebert]

Re: 2004 Mercury 75 HP 4 cycle reliability

A 2004 Mercury 75-HP FOURSTROKE has a power head that was made by Yamaha. Mercury bought the Yamaha power head, installed it on a Mercury mid-section and Mercury gear case, and put a Mercury cowling on it.

The motor has a carburetor fuel system which is somewhat prone to problems, although occurrence of problems seems dependent on fuel blend, fuel quality, fuel age, and length of lay-up periods between use. The usual complaint is the carburetors are fouled and need cleaning. Regular use of a fuel additive such as Mercury QuicKleen has been reported to be effective.

The engine's electrics are Yamaha, although they get fitted with connectors to mate with standard Mercury wiring harnesses. The charger output is not generous.

It runs like a Yamaha and shifts with the typical Mercury KLUNK.

 

[fisher972002]

Re: 2004 Mercury 75 HP 4 cycle reliability

OK,
That would explain why the service manual says merc/yamaha 2000-2004, interesting, thanks for the info.

 

[labelking]

Re: 2004 Mercury 75 HP 4 cycle reliability

I just purchased a new 24' pontoon with a factory 2nd, 2004 Merc 4 stroke. I have 1 minor issue and one cause for concern. I know what you mean by the Mercury Klunk, I thought it was just me. I have run this boat about 1.5 - 3 hours a day 5 days a week since it went into the water in May so you know its getting used and the fuel is fresh. The first of the minor issues is the vibration when running around 2500rpm. The prop looks very clean and free of chips, so I don't know if this is a problem waiting to happen or just a merc thing. The 2nd, and my cause for concern has to do with running at full throttle (5200-5400rpm) for any period of time over 10 minutes. You'll hear a noticable change in the sound of the motor, then it starts smoking. Perhaps I'm just pushing it too hard with a 24' pontoon, 4 adults, and 4 kids on it. Any thoughts?