1999 225 blue water EFI mercury any good???

[adm1476]

So I’m looking at a boat with a 1999 Mercury 225hp blue water EFI motor on it. He says it runs great, has new fuel pump. I was never a Mercury fan, don’t know anything about these. Are they reliable engines? Good longevity? Other than good running and good compression , anything else I should worry about?

 

[GA_Boater]

Sellers always say it runs great. Wouldn't you? Test drive it or take your chances.

 

[adm1476]

I can’t say that was very helpful advice. I’m looking for someone with knowledge about these motors.

 

[GA_Boater]

If you want a thread moved, tell us. Don't start a 2nd thread on the same subject.

 

[QBhoy]

Don’t see why it wouldn’t be good. Haven’t checked but are these not just a 225 optimax engine with more protection against salt use ?
If so, be just a great motor. Compression check is a must as always with such a thing.

 

[adm1476]

I bought it today. It runs good. Has a new fuel pump, and a new tilt trim motor. Compression between 90 and 105 on all cylinders.

 

[Faztbullet]

Wish I had seen this earlier... They are good engines but they have problems with bleed lines rupturing, CDI modules are updated, ignition and EFI ECu are NLAs and have to be repaired or replaced with used and injectors need cleaned every 2 years. If it has the stub shaft lower unit ,needs disassembled and splines greased yearly.

 

[Scott Danforth]

22 years ago when the motor was new, it was a great motor

however with a used motor, its less about the manufacturer and more about condition, condition, condition, condition.

90 to 105 psi compression is a bit on the lower side. maybe check your gauge. the 15 psi discrepancy between low and high is over 5% variance. (its closer to 15%)

 

[QBhoy]

I bought it today. It runs good. Has a new fuel pump, and a new tilt trim motor. Compression between 90 and 105 on all cylinders.

Not to be alarming and it’s likely your gauge is out perhaps...but 90-105 psi is right on what might be considered a worn engine. Generally with these, 100 or lower is an indication of an engine on the verge of needing a rebuild.
that said, apart from the usual issue of some gauges being as much as 30/40 psi out...a dry engine will show low if she hasn’t had a bit of 2 stroke about her in a while. Cold will too. Hopefully it’s just your gauge that’s off.

 

[Faztbullet]

Factory Spec is 90-110 Psi, with a MAXIMUM variance of 15 psi between highest, and lowest cylinder. The motors have a compression relief notch so will be lower at cranking RPM, its for idling purposes.​

 

[Scott Danforth]

Factory Spec is 90-110 Psi, with a MAXIMUM variance of 15 psi between highest, and lowest cylinder. The motors have a compression relief notch so will be lower at cranking RPM, its for idling purposes.​

I stand corrected, however I wonder why Merc has such a variance allowed?

 

[adm1476]

Thank you all for the great info. It seems to run great. However it has sat for a while. It there anything I should do to it prior to putting it back into regular use? I already changed the lower unit oil, and fuel filter.

 

[Dukedog]

I stand corrected, however I wonder why Merc has such a variance allowed?

because they are a line manufactured motor with a minimum spec (piston, ring, cylinder tolerance etc.) to be built by...

 

[Faztbullet]

Install a new impeller, use a good semi synthetic oil, use Quickleen in fuel and good fuel..... $.05 fuel price difference is only a buck for 20gallons

 

[adm1476]

I plan to use non ethanol fuel. Plus an additive. Also going to change the water pump. Thanks! Anything else I should do?