Mercury 250 EFI Offshore

**rdoaner** · 07-03-2020, 05:52 PM

I recently picked up a 30" shaft Mercury 250 EFI Offshore. It has good compression, and the oil injector is disconnected (will be premixing), but I wanted some thoughts on what all I should check and replace on the motor.

First off I'm thinking of replacing the reed valves. Any thoughts, and are there superior aftermarket reed valves that will fit this engine?

Also I've read the ignition coils can go bad. Even if they do, this won't damage the motor, right?

Any recommendations on the injectors?

Also, I've read there's a difference between these EFI motors and some of the newer ones (maybe 2003 and later?). What are the differences, and how will this change how I maintain the motor?

Thanks in advance!

**rdoaner** · 07-06-2020, 12:58 PM

Anyone?

**rgsauger** · 07-07-2020, 11:43 PM

Contact Chris Carson marine for a good set of reeds.

If you drop a coil, you drop a cylinder for power but not the end of the world. They don't fail that often.

You gotta get your injectors cleaned!!! There are numerous sponsors on here. If an injector goes lean, you melt that piston. Baaaaaad chit!

**Peetee907** · 07-14-2020, 10:15 AM

It would be a god idea to go over the fuel system from start to finish. Replace, clean or rebuild those components. Have the fuel lines been replaced especially if running ethanol blends? New water pump and poppit valve are inexpensive and worth replacing as well.

**vnemous** · 07-14-2020, 10:30 AM

If its a two computer motor try to find a 300pm ignition computer, that will wake it up and give you some more rpms

**InjectorService** · 07-15-2020, 12:18 PM

Send your injectors on down!

**vnemous** · 07-15-2020, 12:22 PM

Originally Posted by InjectorService

Send your injectors on down!

You would be up

**InjectorService** · 07-15-2020, 12:25 PM

Originally Posted by vnemous

You would be up

I'm sorry, I didn't realize you guys did injectors as well. Not trying to swipe business from you guys.

Rdoaner - send em out to Fullers! Great guys to deal with!

**vnemous** · 07-15-2020, 05:19 PM

Originally Posted by InjectorService

I'm sorry, I didn't realize you guys did injectors as well. Not trying to swipe business from you guys.

Rdoaner - send em out to Fullers! Great guys to deal with!

No I meant you said send them down, hes in Florida so he has to send them up to get to you

**InjectorService** · 07-15-2020, 05:22 PM

Originally Posted by vnemous

No I meant you said send them down, hes in Florida so he has to send them up to get to you

Ah I see. Man its one of those Wednesdays that feels like a Monday. Must be 5 o'clock somewhere!

**Chaz** · 07-16-2020, 08:01 AM

Ohhh ghee golly ..
Now I'm so corn~fruzed about below the 30th and above the 45th parallels ..

Does the E~crator to the N. pole have anything to do wiff it .. ehh ???

All kidding aside … both shops are great people to deal with ….

**vnemous** · 07-16-2020, 10:26 AM

Chaz I splaine it to you some day.

**vnemous** · 07-16-2020, 10:27 AM

Originally Posted by InjectorService

Ah I see. Man its one of those Wednesdays that feels like a Monday. Must be 5 o'clock somewhere!

Went over your head which is tough since you're so far UP there

Have a good day

**rdoaner** · 07-16-2020, 11:00 AM

Wow this thread really took off! PM sent to Injector Service

**vnemous** · 07-16-2020, 11:24 AM

Originally Posted by InjectorService

I'm sorry, I didn't realize you guys did injectors as well. Not trying to swipe business from you guys.

Rdoaner - send em out to Fullers! Great guys to deal with!

Yes we service all injectors except FICHT. Usual Monday customer drops off and says clean and flow them all and supply calibration specs for each one. Customer gets what they want.