250 4.6L 4 stroke ProXS Repower in process.

[mikesxpress]

Once this thing gets clipped on I'll have allot more info on how it performs against my previous ProXS 2 stroke. I saved all the data so I can directly compare actual performance. No BS about how it "feels", silly videos of a hole shot, or what the promo stuff from Mercury says. I have no brand loyalty to anything so if it's a dog and sucks fuel I'll post it, if it matches the hype I'll post that too. All with with Merc monitor data backup. *Note: The engine doesn't come with a Smartcraft water pressure sensor. That's another $54.00 and required for you to get a reading on your Smartcraft gage. Remove the existing 3/16" plumbing/fitting off the head for the analog gage and screw the sensor in & plug it up. Mercury's reasoning is the computer is monitoring the exhaust for over heat. OK, but they still should have the sensor installed for those of us that watch water pressure on there PROPRIETARY Smartcraft system??? The Opti came with both. Just more silly Merc stuff............

New one arrived for rigging. No more frigging oil filling!!!!!

Removed 2 stroke stuff in advance.


Before gel and finish.


After *Like it never happened.


New on skid. Goes on tomorrow.



You Could've Had A

[bassmasterffej]

Awesome man...Looking forward it!

[Fishysam]

Can't wait to hear your findings

[EuropeanAM]

You've got a PM, Mike.

[21xTriton05]

[grout-scout]

I hope you’re allowed to speak the truth.

[06 SB]

I hope you’re allowed to speak the truth.

Since when are we not allowed to speak the truth? We have always been allowed to IMO. About the only rule here is no bashing or straight up complaining. This is a forum to help give/get advice and things fixed.

[21xTriton05]

Sending your WP sensor now

[mn_bowhunter]

Subscribed

[TritonTRXV8]

Since when are we not allowed to speak the truth? We have always been allowed to IMO. About the only rule here is no bashing or straight up complaining. This is a forum to help give/get advice and things fixed.

I have no idea what he is talking about either.

I am however subscribed to find out how he likes this motor. These v8s intrigue me alot.

[EuropeanAM]

I hope you’re allowed to speak the truth.

Of course he is.

Mike's going to give us his honest opinion on the ENGINE and it's performance (once the engine is on the boat and setup properly). Will understandably require him setting aside some frustrations involved in logistics/delivery of the engine and components.

His write-up based on the engine and how it does should prove helpful and constructive for others.

[mikesxpress]

Serial# 2B529759

After I get thru break in and propping I'll start acquiring comparison data on the 4.6L vs the 3.0L. With a repower on the same hull it should give folks an idea of what to expect from this new V8. As of Friday it was hung and should be finished up Mon-Tue. Rob sent me the water pressure sensor and I'll install that.
A few things that will be of interest for repower folks on a 250HP ProXS.
1. The mandatory installation of the clean power harness at the starting battery
(contains the DTS module) must be done for anything to function. The engine will not trim or start without this in place. As I have all my accessory wires run to terminal blocks/breakers off to the side of the battery with the charger and a single +/- power wire coming off the studs to them I opted to install clamp on battery lugs with studs to the large +/- battery terminals just for the engine power. I wanted to eliminate any opportunity for interference issues.
2. The engine comes plumbed to feed an analog water pressure gage (via hose) but it's does not have the sensor to feed this info to the Smartcraft system. The Opti's had both. Those of us with Smartcraft gages/Merc monitor must buy the sensor and replace the existing 3/16 plumbing fitting. The plug for the sensor is right next to the fitting with a cap on it. 10 minute fix and $54.00. This engine is monitoring the exhaust gas temps to signal overheat which they say is more immediate than lack of water pressure. But that does nothing for us folks that have watched water pressure for years and use it to adjust jackplate height/trim when underway & water pump performance.
3. The alternator drive belt is buried under and around the top oil fill/cable dip stick. Once I get time I'll do some recon on if you can perform a belt replacement on the water but it's not looking good right now...
4. All 8 spark plugs can be removed with only socket and ratchet. NGK LKAR7G9 Be aware these NGK plugs are valued at todays gold prices!!! Oil/filter change appears to be straight forward process with ready access. We shall see...
5. Engine flushing is very easy now. 1/4 turn plug on the side of the cowling pulls out a hose you attach the garden hose to. No tools required.
6. Single handle latch to remove the cowling located on top under the oil lid. Great for removal if your inside the boat on the back deck. You need a ladder if your on the ground.
7. Cooling jacket strainer cleaning is much easier and can be done on the water if necessary.
8. On engine fuel filter change is easy.
9. You don't do much of anything to this engine for 100 hours.

[mikesxpress]

[mikesxpress]

Being as MotorMate can't seem to get a new 4 stoke support out, I'm going to redesign the one off the 2 stroke to fit. I really don't want to mess with individual slip on pipes and SeaStar stabilizer clips. That's going backwards.

[grout-scout]

Since when are we not allowed to speak the truth? We have always been allowed to IMO.

Some threads get censored, but from all the reports so far, most seem to be liking these new motors. But in the end, it doesn’t matter too much, because they are what we have to choose from now. I’m glad he’s giving a through review.


Mike, are you going to start with your previous prop first to see what it does or did you order a new one?

Does anyone know if motor manufacturers recommend one style of transom saver over another? For example: would type “A” good a warranty where type “B” would not.

[berudd]

Looking forward to the details.

Are you sure on the spark plug model. I was curious on the price and found zero google hits on that number. But, realistically should that mater? They are not making a recommendation that you change the plugs every year are they? Automotive four strokes go year and year and 100,000 miles on a set of plugs.

[adchunts]

Very interested in Mike’s apples-to-apples comparison. I’ve been in sales for a few decades, and I prefer real stats over marketing hype.

[mikesxpress]

Some threads get censored, but from all the reports so far, most seem to be liking these new motors. But in the end, it doesn’t matter too much, because they are what we have to choose from now. I’m glad he’s giving a through review.


Mike, are you going to start with your previous prop first to see what it does or did you order a new one?

Does anyone know if motor manufacturers recommend one style of transom saver over another? For example: would type “A” good a warranty where type “B” would not.

Running my true 25P Tempest+ that was on the Opti thru break in then see where I stand with reaching 6150 in the summer.

[mikesxpress]

The V8 4S plugs have a 300 hr or 3 year replacement schedule for normal use.


The motor on my boat came with the incorrect water pressure sender due to a mixup between Ranger and Mercury and it took over a month to get the correct one. The new one screws directly into the block without the hose shown in the picture. On my boat it also provides signal the the dash WP gauge which is digital. WOT WP is 27 on the MercMonitor.
FYI
The second or third time out with the motor at about 1.5 hour mark the motor smoked heavily on a restart after fishing for a half hour with the motor trimmed all the way in. I checked the oil after letting it set trimmed up for a while them trimming the antiventilation with a level the oil was barely above the top mark on the dipstick, so I drained 1/2 quart. There was no sign of gas in the oil and there has been none at 21+ hours. The tech ant Perfect Catch said that he did not add oil and the guys that rigged it at Ranger said that they did not add oil.

Not buying the 300 hour spark plug life just yet. Time will tell.

Already covered the water pressure sensor thing.

I would assume YOU checked the oil level on the engine prior to using it? (Trust no one...) what was the level then? *They ship with oil in them.
Have you had it back on the computer to see if any fault codes show up? No matter where it's left in the trim range it shouldn't smoke.

[howieranger]

Mike the oil level was the same the day I brought it home. Having the door at the top of the cowl is really nice because it weighs a bunch. Standing in the boat with the motor trimmed up a bit is the easiest way. As for spark plug life it makes some sense because you are not burning oil and firing 1/2 the number of times that a 2 stroke 250 PRO XS does. I am more skeptical of the 300 hr/3yr on the water pump impeller replacement. I have not seen anything that shows the impeller being made from a longer lasting material. I have had it checked with the latest software (I think the tech referred as G3) and there were no problems.