Go Back  Offshoreonly.com > Owners Forum > Baja
moving from 496 mag to 496 HO >

moving from 496 mag to 496 HO

moving from 496 mag to 496 HO

Old 10-16-2017, 02:09 PM
  #1  
Registered
Thread Starter
 
Join Date: Apr 2017
Posts: 22
Likes: 0
Received 0 Likes on 0 Posts
Default moving from 496 mag to 496 HO

Hello,

I have a Baja 275 and the engine blew on me late this season (496 mag). I have ordered and will be installing a new 496 HO. I was wondering if anyone can chime in on what type of performance increases I can expect? Increase in speed? Acceleration? Is there a difference in sound?

Thanks for your input!
275BBoss is offline  
Old 10-16-2017, 02:22 PM
  #2  
Platinum Member
Platinum Member
iTrader: (6)
 
F-2 Speedy's Avatar
 
Join Date: May 2012
Location: Midwest & T-Rock
Posts: 6,966
Received 46 Likes on 27 Posts
Default

your picking up 50 hp, I would guess 2-3 mph if that, more cam in the HO, so maybe a little more thump
F-2 Speedy is offline  
Old 10-16-2017, 05:41 PM
  #3  
Registered
 
Join Date: Apr 2013
Posts: 87
Likes: 0
Received 0 Likes on 0 Posts
Default

Yeah.
2-3 sounds about right.
i really liked my HO, has a nice lumpy idle.
Tom272Baja is offline  
Old 10-16-2017, 07:15 PM
  #4  
Registered
 
Kefurr's Avatar
 
Join Date: Jan 2014
Location: D'Iberville MS
Posts: 119
Likes: 0
Received 0 Likes on 0 Posts
Default

You will need the ecu reprogrammed for the HO
Kefurr is offline  
Old 10-16-2017, 09:19 PM
  #5  
Registered
 
Join Date: Oct 2014
Location: Delavan, Wi
Posts: 65
Likes: 0
Received 0 Likes on 0 Posts
Default

I have a good spare 496 HO Ecm no longer needed. I have sold the boat it was for. If interested please contact me at
847-204-7876
Jeff
Lake Bound is offline  
Old 05-01-2018, 08:43 AM
  #6  
Registered
Thread Starter
 
Join Date: Apr 2017
Posts: 22
Likes: 0
Received 0 Likes on 0 Posts
Default

The HO is in and ready. Does anyone know if I will need a different prop?
275BBoss is offline  
Old 05-01-2018, 08:55 AM
  #7  
Registered
 
Join Date: Oct 2016
Posts: 10
Likes: 0
Received 0 Likes on 0 Posts
Default

What prop do you have now?
jbowling is offline  
Old 05-01-2018, 09:02 AM
  #8  
Platinum Member
Platinum Member
iTrader: (6)
 
F-2 Speedy's Avatar
 
Join Date: May 2012
Location: Midwest & T-Rock
Posts: 6,966
Received 46 Likes on 27 Posts
Default

Break the engine in first, then see where the rpm is at WOT, if you're running up on the limiter you may want to change it.
F-2 Speedy is offline  
Old 05-01-2018, 09:08 AM
  #9  
Registered
Thread Starter
 
Join Date: Apr 2017
Posts: 22
Likes: 0
Received 0 Likes on 0 Posts
Default

I have a merc mirage plus 23p. My second question is what should be done to properly break in the motor.
275BBoss is offline  
Old 05-01-2018, 02:24 PM
  #10  
Registered
 
Join Date: Oct 2016
Posts: 10
Likes: 0
Received 0 Likes on 0 Posts
Default

Same prop as I run on my 275 with HO. What I've seen on Merc's break in:

20-Hour Break-In Period

IMPORTANT: The first 20 hours of operation is the engine break-in period. Correct break-in is essential to obtain minimum oil consumption and maximum engine performance. During this break-in period, the following rules must be observed:

Do NOT operate below 1500 rpm for extended periods of time for the first 10 hours. Shift into gear as soon as possible after starting and advance the throttle above 1500 rpm if conditions permit safe operation.

Do NOT operate at one speed consistently for extended periods.

Do not exceed 3/4 throttle during the first 10 hours. During the next 10 hours, occasional operation at full throttle is permissible (5 minutes at a time maximum).

Avoid full throttle acceleration from IDLE speed.

Do NOT operate at full throttle until the engine reaches normal operating temperature.

Frequently check engine oil level. Add oil as needed. It is normal for oil consumption to be high during the break-in period.

After Break-In Period

To help extend the life of your Mercury MerCruiser power package, the following recommendations should be considered;

Ensure that propeller allows the engine to operate at or near the top of the specified WOT rpm range (Refer to Specifications and Maintenance) when at full throttle with a normal boat load.

Operation at 3/4 throttle setting or lower is recommended. Refrain from prolonged operation at WOT rpm.

Change the oil and oil filter. Refer to Specifications and Maintenance.
jbowling is offline  

OSO Sponsor
OSO Advertiser
OSO Advertiser

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service - Do Not Sell My Personal Information

Copyright 2018 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.

OSO Advertiser