New 150 Pro XS 4s Powerhead

[Mitriton]

My new 150hp 4 stroke Pro XS (#2B578744) lost the oil pump at 15 hours and the motor got toasted. Mercury gave me a new long block but I don't like the fact that my new motor had components removed and replaced at such a young age. Also, I lost almost 2mph on the top end (gps) but the new motor only has a little over 2hrs. so I'm hoping I get it back. All the research I've done told me the 150hp 4 stroke had zero issues so I hope that proves to be the case with this new powerhead. I was really liking the motor until the 15th hours but I'm hoping it will regain my confidents. Also learned that regardless of what Mercury says the fuel economy isn't as good as the 150hp Opti it replaced. At a slow cruise (24-25mph) I could get 8mpg and up to around 45mph I would get a little better than 6mpg. The Pro XS loses about 1 mpg at the same speeds. I'm getting these numbers using smartcraft fuel burn per hour with gps speed. Boat is a 2000 Triton TR186 with 6in. manual jackplate and 24inch pitch Fury prop. The Opti had a 23in. Tempest Plus so I'm wondering if that is the difference.

[idratherbeefishin]

Dang that sucks , but I still think the 150 4-stroke is a solid motor I think the oil pump going out was just a random thing that happened but at least you have a good warranty to back it up and it's documented

[Northwoodswalleye]

I owned a 2016 150 merc that blew up in the first 45 minutes. New powerhead and all was good. I sold it with 230 hours and it was a good motor. Merc will take care of you

[Wheelman]

The Tempest has more natural lift than the Fury as I've run both on Sabre FTD and it will affect mpg as the boat rides deeper in the water with the Fury meaning more drag and higher load on the engine. Sorry to hear of your troubles and hope that helps, curious what it ran WOT with 2-stroke vs 4-stroke now?

[Mitriton]

The 2 stroke ran 58.5-60mph at around 5,500-5,600rpm (I think) with the 23in. Tempest Plus. The original 4 stroke ran 61.5mph at around 5,900ish rpm with the 24in. Fury. The replacement motor so far with just over 2 hours has hit 59.9 mph at around 5,800ish rpm, also with the Fury prop. The rpm on the smartcraft is fluctuating some so hard to give accurate rpm readings. Of course conditions altered the numbers somewhat which may explain the lower readings. With the 4 stroke Pro XS the 23in. Tempest speed was around 58mph but the tach hit 6,100rpm so I came off the throttle right away. I'm still wondering if it would be worth the money to reprop the 23in. Tempest to 24inch. Thanks guys for the encouraging replies.

[Wheelman]

The 2 stroke ran 58.5-60mph at around 5,500-5,600rpm (I think) with the 23in. Tempest Plus. The original 4 stroke ran 61.5mph at around 5,900ish rpm with the 24in. Fury. The replacement motor so far with just over 2 hours has hit 59.9 mph at around 5,800ish rpm, also with the Fury prop. The rpm on the smartcraft is fluctuating some so hard to give accurate rpm readings. Of course conditions altered the numbers somewhat which may explain the lower readings. With the 4 stroke Pro XS the 23in. Tempest speed was around 58mph but the tach hit 6,100rpm so I came off the throttle right away. I'm still wondering if it would be worth the money to reprop the 23in. Tempest to 24inch. Thanks guys for the encouraging replies.

I ended up liking a trophy as best all around prop, ran within a mph of the Fury and stayed off the limiter unlike the Tempest. All were 24" pitch, but I have the standard 4-stroke gearing of 1.92 and 5900rpm limiter.

[moetorola]

Did you measure your Prop Shaft to Pad (P2P).

Could be slightly different, and an inch can make a huge difference on some boats!

I would probably play with engine height (P2P) and try a 24P if it was my boat.

[billnorman1]

No break in on a 4 stroke?

[EuropeanAM]

Yes... should just now be getting it opened up for short periods. If your performance is still off at 15 hours, have the throttle cable setup checked.

[contium]

No break in on a 4 stroke?

Break in is full throttle for 1 minute every 10 minutes of running.

[berudd]

Its a machine and machines do break. This one as been, by all appearances, a very reliable one. IMO, you're just suffered a little bad luck. Unless ALL conditions, including load in the boat, were identical with the two speed runs you mention, I would not see that as much of a difference.

And I would not be concerned about taking good parts off the old motor. They are still basically brand new anyway.