View Full Version : Allison XTB w/ 2001 Mercury 200XS

05-11-2001, 07:43 PM
well I finally got a 200XS on my boat...

for those not in the "know" the 200XS is the 2.5L optimax racing motor. You can find all the specs on the motor at the mercury website. Last year, the 24 hours of Rouen was won with this motor. The motors used in the race are the same motors that you can buy (except for the 12" race midsection). As far as weight goes, mercury lists the motor to be around 400#. It is basically about 25# heavier than a promax or 260/280 and roughly the same weight as a 2.5L production EFI (racing motors shave a lot of weight in the cowls). The extra weight of the optimax is from the 60 amp alternator, the belt driven air compressor, and extra plumbing for the fuel system. You can get the 200XS in a standard 20" or 15"SS model.

200XS PERFORMANCE (ON PAPER): The 200XS runs a very strong 200 hp (remember the +/-10% thing). It revs to 6900 before a rev limiter kicks in. When compared to a production 200 EFI, it really kicks the production 200's butt. (remember though, that the production 200 is calibrated to run on 87 octane and be less of a performance motor). Where the 200XS really shines, though, is fuel economy. They really go easy on the gas at rpms less than 5000. So if you prop the boat to cruise around 4500, you will get very good fuel economy. I have heard reports of guys running flats boats that have decreased their fuel consumption by over 50%. The performance, coupled with the good fuel economy and the high gas prices is what made me choose to put the 200XS on my boat over a 225 promax.

MY FIRST IMPRESSIONS: Unfortunately, it was raining very hard Thursday night when I finally finished the rigging and was ready to water test it. However, I went anyway! The motor starts easy and purrs like a kitten. Idle quality is noticably better than and EFI (and I thought the EFI motors idled nice!). Out of the hole, the motor really gets up and goes, which surprised me cause the production optimax motors arent really known for an extremely good holeshot. Anyhow, I was able to break loose my 26" trophy, which I never was able to do with my 150EFI. Once on plane, mid range acceleration is brisk. The motor is very responsive. Unfortunately, I wasnt really able to get above 50 mph because the rain was pelting me too hard...
I will hopefully be able to get some speed runs this weekend and I will post the results...

tonight (Friday) I got a chance to open up the new motor... all I can say is WOW! I am grinning ear to ear!

The first run, I got 76 mph. The bow was riding a bit high, so I raised the jack plate a bit. Then ran 81. I did a little more tinkering, and got a solid 83 mph GPS! (for you guys chuckling at my speed, remember I have the big-ole, 21 foot XTB, not some little potato chip racer! ;) ) This was running my fishing prop (26 trophy), full tank of gas, 3 batteries, 30# of ballast, and all my fishing stuff. I gotta try my 26 ET! Mid 80's shouldnt be a problem once I get used to things and get it a bit more dialed in....

05-21-2001, 08:56 AM
Glad to hear the positive report on your 200XS. I have been a big fan of Optimax because I was hoping the system would give us 2 strokers a few more years against the EPA. DFI motors (like everything that is pretty new) have suffered a black eye because I think the manufacturers were pressed to get this technology out before it was truly ready. But as you can see, when everything is working as intended the system is awesome. I was back at a Merc school in Florida earlier this year and they had a 200XS for us to play with.
She looked and sounded pretty cool...even on a test stand!
Wish I had one on the back of my 20' LaveyCraft!
Curious, are you running any of the "SmartCraft" guages with your setup?
Keep me posted on the progress of this engine. I own a few shares of Orbital Engine (OE on the New York Exchange) and fellow shareholders will enjoy hearing about your experience with this motor.
Steve (sosmerc)

05-21-2001, 09:07 AM
Would like to know what oil you are using and if you do get any spark plug fouling would like to know how many hours on engine when they do start to foul. (plug fouling has been somewhat of a problem on production models....you may not experience any...time will tell).