Repower from 88 XR4 to 08 Opti?

[chillywillie]

Hello everyone,

Looking for some opinions and value those on BBC. Current motor is an 88 Mariner Mag II 150, boat new to me in April, still runs decent, gets my Gambler 183 out the hole in about 3 secs and pushes it to about 60 but I want a reliable motor that I can feel as confident as one can be in an outboard to feel good about taking some trips and hitting bigger lakes.

So I’m scheduled to take it into my local Mercury guy next week to see what all it needs but I’m also cautious about sinking a chunk of money into a 25 year old motor. Came across an 08 Optimax 150 in great shape for $3500 + my current motor. So my question is if you were me would you freshen up the old motor or put that money towards the Optimax? If I did switch what would I gain or sacrifice performance wise? And what are the hidden costs if I made that switch? New controls or is there an adapter? Do I need Smartcraft or is it just nice to have?


Thanks!
William

[leonreno]

Your old motor will be cheaper to repair as far as parts, but those parts will also be getting harder to find since the motor is getting near 40 years old. Your compression numbers, even for the low one isn’t bad. I don’t know the difference in performance but you will get better gas mileage with the Optimax and you would think it would be more reliable. But parts for Optimax motors when you need them can be pricey, for items like injectors (gas and air), the compressor, and electronics. Personally I would save up a little more and look into a used (or maybe new) Mercury 4S 150hp, they aren’t that expensive and would be more reliable than the Optimax and older EFI. I think they started making them around 2013 or so.

[SilverFox579]

I'll speak to the Optimax but not the boat. I've had a 150 Optimax since new in March 2009 and has been very dependable and trouble free. A leaky crankshaft seal repaired under warranty but no other major concerns at all. Routine maintenance is relatively simple, spark plugs, lower unit oil, water pump, compressor air filter, & fuel filter annually. Recommended to have injectors cleaned/calibrated at 400hrs or 4yrs and had mine done by Integrity Injection a few years ago at which time I chose to upgrtade to TDR carbon fiber reeds.

In almost 14yrs I've replaced a leaky oil pump and one direct injector Don identified during the injector cleaning/calibration process. Beyond that, it has given me excellent service, great fuel economy, starts in seconds every time, and I've been very happy with it.

[JOE54]

^^^^^ agree with both above well maintained mtrs will last and last , in the end its all a gamble , the 4strks seem to be very good , just not for me

[EuropeanAM]

My $0.02 (for what it's worth):

Based on your specific question about rebuilding an XR4 or purchasing a Good, Used 150 Optimax: Have the Optimax checked carefully- get the serial number (I'll be glad to look it up), compression test, make sure it's all up to date on maintenance (including water pump and a new BELT).

If it's sound, and checks out well, I think your money is better invested in the newer engine. In the end, it will probably save you some money on fuel (you'll be amazed at how much less it burns).

Now... if there's even the slightest thought of moving up to a 150 Fourstroke: NOW would be the time to consider it. The Opti is a great engine. The 150 Fourstroke is, IMHO, even more durable in the long run.

[chillywillie]

Thank you VERY much everyone, truly appreciate the comments. I’m going to sit tight until next week and see what my mechanic thinks (Dennis Berry who is truly one of the old school best Merc guys there is). And decide from there. I hadn’t thought about four strokes so something new for me took into too.

What I’d really like to find is a 175 which is my max HP for the boat but they are like unicorns!


Thanks again,
Willie