Flashing a Mercury 250 ProXS 2 stroke questions

[Mygreenihc]

Gentlemen,

I have a 2016 Bullet XRS with a 2 stroke 250 Pro XS Mercury and two 8 foot power poles. I have 3 lithium troller batteries and plan to buy a lithium cranking battery when this one dies.

I understand that it is possible to get "Up to" an additional 20 horsepower with a flash. S, I guess my first question would be, is the flash worth fooling with?

My second question is, if I do get the flash, would the additional horsepower be enough to go up one prop pitch?

I currently run the 27 Hydro prop that came on it from Bullet, and it has good hole shot and runs out about 76 - 78 mph with one person when conditions are perfect and I have the time to get it up there. I want to keep the hole shot but would like to add 2 to 4 mph. Is the additional hp enough to turn a 28 pitch prop? What prop would work best on this setup?

Sorry about all the questions. I think I said enough for you to understand what I am thinking of doing, so if you have any advice on this please feel free to chime in even if it is not a direct answer.

Thanks
Brad

[gehol]

Not likely to get a measurable increase. Where does the horse power increase come from? Increase rev limit? Can you reach rev limit now?

[Mygreenihc]

That is a good question. The engine feels like it is around redline, but I have not looked at the tach to see exactly where it is. That, I will have to determine.

[gehol]

My point is if you can't reach rev limit now putting a bigger prop on will accomplish nothing. If you can't reach the limit, and the "flashing" simply raises the rev limit, then I see little use for the flash.

[gehol]

Also would be good to know what lower unit you have and your P to P measurement.

[muddywaters]

I have a 21 xrd with a 2014 Mercury 250 Pro xs, torq master 2 lower 1.75 gears and I am running a 28 bravo xs on mine, and In the dead cold of winter I can just touch the rev limiter occasionally.

[jaxbass]

My fishing partner has a 2017 SDC, 250 pro xs 2 stroke, 28 bravo and can runs 78-79 loaded and 80-81 solo and light. Might want to try a Bravo and see how much you gain and not mess with adding a few horse power to motor.

[muddywaters]

12135557[/URL]]I have a 21 xrd with a 2014 Mercury 250 Pro xs, torq master 2 lower 1.75 gears and I am running a 28 bravo xs on mine, and In the dead cold of winter I can just touch the rev limiter occasionally.

I run 78-79 loaded, 80-81 light. Best overall on max recall 84.3 mph.

[BassmanZF6]

Who is flashing mercury motors now?

[hyperflow]

There's performance to be gained on the 250's. Alien cowl, light weight flywheel, V-stack, Light weight compressor wheel. Should be a solid 2mph gain.

I don't have any experience with the DBR flash on a 250, But we tried the alien cowl from my 300XS on my buddys 250XS and it gained 1.4mph first pass.

[sowenssw]

From what I understand Merc put the crunch on flashing, no one is doing it now to my knowledge. I have a 250R and had it flashed before the big flash cut. On the v8's its a game changer, it took my 250R to 325hp. We had my Dad's 225 2 stroke flashed a few years ago and it really wasn't worth the money for the gain he saw. He might have seen 2 mph increase, a few hundred rpm more. It does re-range the limiter to I think 6800 on my v8, not sure on the 2 strokes. We went Simon on both our tunes.