Merc 200 EFI - the good, bad, & ugly

[kitebuz]

I am in the process of planning a repower. I have a pair of '89 Evinrude 120's right now. In looking at the combination of price, reliability, and efficiency, I am narrowing my search down to mid/late '90's EFI engines - w/ the Merc's topping the list.

Specifically, I like the weight to power of the Merc 200 EFI's, and have read good things about them.

What I am trying to figure out is are there certain years or models to avoid, and any known issues I should be aware of on these engines?

The Yam 200 ox66's were another close contender, but they seem to demand a higher resale, and (call me old-fashioned) I'd still rather hang a US (or Canadian-Evinrude) motor than a foreign one if most factors are close (no disrespect intended - & I'd take a set of 200 HPDI's in a 2nd). The Evinrude/Johnson Fitch's are out, but my second or 3rd choice would likely be the '93-'97 carb'd versions (easier rigging etc staying w/ same brand).

Any comments or experience on the Merc 200 EFI's would be appreciated - thanks.

 

[yamamarinetech40]

Re: Merc 200 EFI - the good, bad, & ugly

I'm also certified in Merc's, but don't see that many down here on the Gulf...I can't understand, and would love an explanation from someone, why Mercury has stuck with It's crazy oil injection system...instead of a simple pump, these people pump air into the tank in the boat from the motor and let that PUSH the oil from tank to motor...if there is an air leak in remote tank, NO OIL...have repowered lots of Merc's because cap not tight, not sealing, etc...I am certainly pro-Yamaha and the OX-66 is about the most bullet proof motor they built...which says LOTS

 

[Texasmark]

Re: Merc 200 EFI - the good, bad, & ugly

Boy-son's '95 150 has a small tank under the cowl with an oil level sensor, which is fed from that remote tank you mention. If the remote tank fails to get oil up to the internal tank (which feeds the pump), or there is a bubble in that internal tank, the low oil warning horn will sound.....and yes you need to be careful and pay attention when replacing the lids to either tank to insure that you get them on tight.

I don't know which system is better. One thing I always wondered about is what I read about Yammies where they (were said to) use independent injection rather than a common pump like Merc. How do you know if one cylinder gets starved for oil? Do they have 6 separate monitors feeding a/the warning horn?
--------------------

On the 200's compliments of the '94 sales brochure (this is a Mariner brochure, but the Merc should be the same thing):

You have several 200 hp engines which are all 2.5 liter; couple of offshore, a regular one, and a Magnum EFI.

Will discuss the regulars.

Wt is 395 and 410. For comparison, you can go all the way down to 100 hp and still be at 348 lbs. So, the 200, as you said, is a lot of whoopie for the extra 50#.
Single point oil injection.
New streamlined gearcase

The Magnum EFI advantages are:

WOT has 200 more rpm's.
Ignition is not only Cap Disch, but there is also an Electronic Control Unit that offers key turn starting just like your car. Has engine monitors to feed the ECU computer.
Two different gear ratio's available (might pay attention to this if you are buying a pair to insure that you get the same ratio in both).
40 amp alternator (Yammie is said to have a 20 A)

Said it was in response to what Bassers wanted; rugged, reliable, good hole shot, excellent fuel economy, and fast.

HTH,

Mark

 

[yamamarinetech40]

Re: Merc 200 EFI - the good, bad, & ugly

Don't know what they were referencing, but Yama's have only one oil pump, with individual oil lines to each cylinder. Yamaha, by the way, now has the same engine diagrams as we do at dealership, just go to Yamaha, Parts and Service, Parts Catalog and pick any year/engine and you can view all systems and parts, pretty cool they give it for free.

 

[kitebuz]

Re: Merc 200 EFI - the good, bad, & ugly

Thanks for the replies - already learning things - didn't realize it had a pressure fed oil system. Does any one simply disconnect the oil system, and manually mix oil in gas as is common w/ the VRO system on the Evinrude?

Good point to double check gear ratios. i was figuring the weight at 430 lbs ea, but maybe that was one of the Offshore models (25"), but don't know what the other diff's would be. I am in saltwater, so will assume Offshores are what I want. Don't need the extra 200rpm. I am mainly looking for a lower cruise rpm to to stay in the 30-35mph cruise (currently @4200-4800 range).

Any other specifics to look out for? Are Mariners the same engine, or to be avoided?

 

[rodbolt]

Re: Merc 200 EFI - the good, bad, & ugly

on the oiling system differences between the EFI merc and the OX66 the yamaha version is a bit more robust.
both systems mix the oil with the fuel and then feed it to the injectors from a vapor seperator.
both use diaphram type fuel lift pumpos that require maint.
the mercs are vunerable to oil drive gear failures if stored improperly.
seems they still use the failure prone nylon oil pump drive gear.
both systems have drawbacks. the yamaha setup is rather complex but works well.
the merc system is simple yet suffers stupid failures that should have been addressed in the 80's.
the OX66 setup uses an O2 sensor which can cause a powerhead failure if the correct maint procedures are not adhered to.
mercs seem to suffer way to many electrical failures,regulators,oil control modules,idle stabilizers and stators and switchbox failures.
electrical failures on the yamahas are rather rare.
however if both are well maintained by competent techs and the owner adheres to the maint schedule both engines worked well.

 

[kitebuz]

Re: Merc 200 EFI - the good, bad, & ugly

Thanks, Rodbolt. Good info. I guess the key is to be careful whose engines you buy - the guy that maintains them vs the guy that "rode em hard, & put em up wet" so to speak.

This may be a dumb question, but are the Mercs & Mariners the same engine (of the same model & year)?

 

[rodbolt]

Re: Merc 200 EFI - the good, bad, & ugly

are mercs and mariners the same? depends on the model and year. on the 200 EFI, no they are not the same.
one is black and one is silver metallic.

 

[kitebuz]

Re: Merc 200 EFI - the good, bad, & ugly

Good to know - I'll be careful on that color choice...