Notices
General Boating Discussion

Mercury 300 promax

Thread Tools
 
Old 07-17-2006 | 10:59 AM
  #1  
Enforcer2's Avatar
Thread Starter
Registered
 
Joined: Nov 2004
Posts: 831
Likes: 2
From: Ocean Pines, Maryland. Wish I was at MANGOS in MIAMI!
Default Mercury 300 promax

Looking for info on the Mercury 300 pro max. Considering swaping my wife --I mean my triple 225 optimxes on my Midnigh tExpress for triple 300 promaxes.

A lot of bay use, occassional offshore use, want to go faster
Enforcer2 is offline  
Reply
Old 07-17-2006 | 11:24 AM
  #2  
Zero Patience's Avatar
Gold Member
 
Joined: Feb 2001
Posts: 1,596
Likes: 12
From: Crystal River Fl,USA
Default Re: Mercury 300 promax

300x is not available anymore. 300 XS Stroker Optimax is available now.
Zero Patience is offline  
Reply
Old 07-17-2006 | 12:49 PM
  #3  
Enforcer2's Avatar
Thread Starter
Registered
 
Joined: Nov 2004
Posts: 831
Likes: 2
From: Ocean Pines, Maryland. Wish I was at MANGOS in MIAMI!
Default Re: Mercury 300 promax

I was refering to the older models. Seems like there are a lot on the market now due to the new 300 opti's. Looks like a good opportunity to purchase some running 2000-2003 models.

Any info positive or negative on the 300 promaxes??
Enforcer2 is offline  
Reply
Old 07-17-2006 | 12:56 PM
  #4  
CustomRigger101's Avatar
Registered
 
Joined: Oct 2002
Posts: 791
Likes: 0
From: Lighthouse Point Fl
Default Re: Mercury 300 promax

ran a 32 skater that had trip 300.. middle motor always get kick up alittle more on that step up but where good strong motors

IMHO if i was going to rerig a outboard boat i'd look into the DF250's.. good motor.. can be picked up for somewhere the 9k range.. fresh out of the box.. 3 year warrenty
CustomRigger101 is offline  
Reply
Old 07-17-2006 | 01:04 PM
  #5  
dirtlawyer's Avatar
VIP Member
25 Year Member
VIP Member
 
Joined: Dec 2000
Posts: 485
Likes: 8
From: Redington Shores, Florida
Default Re: Mercury 300 promax

Enforcer - I was looking into the same thing recently - was told from a couple of sources to stay away from the 300 Promaxes - they were only out for a few years and were then replaced by the 300X. Apparently Merc had some powerhead failures with the 300 Promaxes.

If any one has heard differently or has a different experience, please advise.
dirtlawyer is offline  
Reply
Old 07-17-2006 | 06:57 PM
  #6  
Enforcer2's Avatar
Thread Starter
Registered
 
Joined: Nov 2004
Posts: 831
Likes: 2
From: Ocean Pines, Maryland. Wish I was at MANGOS in MIAMI!
Default Re: Mercury 300 promax

Thanks I'll keep checking around for more info. I'm glad you mentioned 300X and Promax I didn't realize there was a difference. I checked with two local mechanics and neither have had any experience with them. I have found some forums that advised they drink the fuel and oil like crazy and parts are hard to find. Everything has to be special ordered.Would be nice to be able to afford bolting on three the new 300 Merc Optimax Strokers.
Enforcer2 is offline  
Reply
Old 07-17-2006 | 10:17 PM
  #7  
Registered
20 Year Member
 
Joined: Apr 2001
Posts: 2,983
Likes: 39
From: East Coast
Default Re: Mercury 300 promax

We have 300 promaxes....have been great so far. Around 300 horse each

My friend has the 300x's...loves them. About 30 horse more and better fuel economy. Both are nice two strokes
cowisl is offline  
Reply
Old 07-18-2006 | 11:41 AM
  #8  
Enforcer2's Avatar
Thread Starter
Registered
 
Joined: Nov 2004
Posts: 831
Likes: 2
From: Ocean Pines, Maryland. Wish I was at MANGOS in MIAMI!
Default Re: Mercury 300 promax

I have been hearing definetly go with 300x's, apparently powerhead problems with 300 pro maxes.

Thanks for reply
Enforcer2 is offline  
Reply
Old 07-18-2006 | 12:22 PM
  #9  
Enforcer2's Avatar
Thread Starter
Registered
 
Joined: Nov 2004
Posts: 831
Likes: 2
From: Ocean Pines, Maryland. Wish I was at MANGOS in MIAMI!
Default Re: Mercury 300 promax

I stand coreected talked to Diamond Marine. They advised that the 300 pro maxes are great engines and in contrast he has seen more 300x powerhead problems.

They advised that this is not due to the 300 promax being better than the 300x it is mostly due to the 300x having heavier cranks and the motors are beig turned up more than they should be resulting in failure.

He suggested the 300x over the 300 pro max mostly due to the newer model years of the 300x.

Hope it helps everyone.

It' shot as out here.
Enforcer2 is offline  
Reply
Old 07-19-2006 | 02:30 PM
  #10  
Registered
 
Joined: Mar 2006
Posts: 3
Likes: 0
From: Austin, Texas
Default Re: Mercury 300 promax

Another diff, X's have electronic oil injection and the older Promax's have a plastic gear in the oil pump that can fail if the motor is cranked up above the factory limiter (6500). Many people that turn the Promax's harder install an oil pump block off kit and mix their own fuel/oil.

I am running a '98 Promax that just had it's 3rd powerhead installed when I bought the boat. Appearantly they resolved the issue by replacing a bad wiring harness or something like that.

There was also an issue with the early coils, so I replaced them.
I have had no trouble with it, fill it up with fuel and oil and run wide open (6k) all day long.

ScreamAndFly has tons of info on any outboards (can I say that here?)

Enjoy,
Joe
supercobrajet is offline  
Reply


Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

Copyright © 2026 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.