OK let's talk about XB mods

[modvp]

Thanks Richard...I will attempt to do the mods you suggested, in addition to the cowl mods.

[kylkBullet]

killr bee sent you an im

[FSHN ROD]

I cut the bottom 5 inches off my stock tuner and am halfway through taking my mid off. Will it hurt anything? No other mods. I had 2 stock tuners layin around in case your wonderin how I cut it before removing mid.

[kllr bee]

It will be ear piercing loud and you will not have enough exhaust going into lower unit to ventilate your prop. The marine patrol will stop you every time they see you also. other than that, have fun.
Richard

[champion221elite]

Thanks for posting your info kllr bee I'm currently running a bone stock 1997 Mercury 225 EFI on my 22' Champion.

It's a good running motor that's capable of pushing my barge to the 68-72 mph range depending on load. Without going too overboard, what are a few mods that will help my motor run better without decreasing the overall lifespan?

[kllr bee]

You can raise the rear cowl piece for about 5 bucks.(pictures in common questions section). Carbon fiber reeds will increase the life of it(you should see what a broken steel reed can do to a motor) this will improve off idle through midrange performance. The other things are at the start of this post.
Richard

[Kenora Champ181]

i broke a stock reed 2 years ago and got super lucky that it fell harmless outta the way and didnt get eaten the piston!

[kllr bee]

I lost two blocks from broken steel reeds, so I will never have them in anything I own.
Richard

[bass bullet]

I have a hydrotech tuner in my 250xb, it made a big diff in the midrange, gained 200 rpms and 3.5 mph. I also have 300ecu, 300pm heads, poppet diverter, cowl mod, so I think it all complements itself.

Its now a mid range torquemonster and pushes my 21xd bullet to 85.5 mph @ 6400 rpms.

i have light flywheel coming and am going to get mad efi to cut my heads to 61cc.

My question is what about a SVS or the new MAD efi intake for 3 litres, or what about just adding the SVS reed plate over stock.

Also what about the adjustable MAD timing sensor , what can you achieve with this.

[EuropeanAM]

<table width="90%" cellspacing=0 cellpadding=0 align=center><tr><td>Quote, originally posted by bass bullet &raquo;</td></tr><tr><td class="quote">Also what about the adjustable MAD timing sensor , what can you achieve with this. </td></tr></table>

I'll address this one specific question (others are likely more qualified to respond to the other portions).

An adjustable timing sensor involves "tricking" the ECM/ECU/PCM into thinking that TDC is somewhere other than "actual TDC", ultimately resulting in altered engine timing.

Although this MAY (or may not) result in increased POWER, it can also contribute to increased combustion chamber temperatures, pre-ignition of fuel/air mixture, and potentially, detonation and/or piston failure. Extreme caution is urged when attempting any modification of the intended timing and/or timing curve!

[kllr bee]

Believe me when you get 61 cc heads and are using the 300 ECU you are at the timing limit on being able to use pump gas in that motor. I have found that there is a limit to what you can ask these motors to do, and you are about there. You need to put a nosecone on that torquemaster if it does not have one. you are in blowout territory with those speeds. If you want a MAD EFI intake I have one for sale send me a pm.
Richard

[Fador]

[aalbert]

Great thread...

I wanted to revisit the exhaust tuners a bit.. You mention that the 250XB and 250XS were your favorites due to the noise / performance ratio (being quiet andntion deattelivering acceptable performance).. Can you expand on that?

I am thinking along the same guidelines as you are, in that I want performance, but without the headache of attracting unwanted attention or having to make my 5yr old wear hearing protection while on the boat.

My motor will be going back together soon, and I have a MAD efi tuner or the stock 2000 225 tuner that I can put back in, but would like a compromise somewhere in between.... Other mods, as it stands now are: Brucato SVS, Boyesen reeds, 250XB ignition computer, Simon flywheel, my choice of 250XB heads or 300 PM heads, Simon poppet diverter, torquemaster lower, and an alien cowling... If you have any suggestions to the above formula, let me know (pending would also be a different fuel computer, but I kinda want to run it first, so I can give Simon some feedback).. This is all going on a 23' Mako CC.

[EuropeanAM]

Personally, I'd stick with the stock 2000-225 tuner. Re-drill ALL of the idle relief holes to 3/8" ID (just to ensure none of them are restricted) before reinstalling. I WOULD NOT recommend cutting this tuner in any other fashion.

[aalbert]

EuropeanAM... Thank you for the real world advice... I think I will do just that.

[Dite]

I have a 2002 250 XB Pro and have run Pennzoil Full Synthetic for many years without any problems.....what is the concern about running fully synthetic vs a blend?

[EuropeanAM]

<table width="90%" cellspacing=0 cellpadding=0 align=center><tr><td>Quote, originally posted by Dite &raquo;</td></tr><tr><td class="quote">I have a 2002 250 XB Pro and have run Pennzoil Full Synthetic for many years without any problems.....what is the concern about running fully synthetic vs a blend?</td></tr></table>

Without getting too highly technical (this type of question ALWAYS brings out a ton of arguments/opinions):

The primary concern exists during initial breakin of the engine. A "true" fully synthetic oil can actually INHIBIT proper ring seating.

Mercury has recommended Synthetic Blends for ALL their steel-sleeved 2-stroke outboards (and continues to do so)- these blends provide the benefits of both a traditional "petroleum" base, AND Synthetics.

[Dite]

I am the second owner (bought it 4 years ago). The original owner used the Pennzoil synthetic blend for about 350 hours on the motor. I then switched to the Pennzoil fully synthetic because it had worked so well on my other outboards. Do you think I am "safe" to continue using the fully synthetic or should I change back to the blend?

[EuropeanAM]

If it were mine... I'd be running the Synthetic BLEND (in my case, Mercury or Quicksilver Premium Plus).

[Harbo]

I have a 1998 3.0 L 225 EFI, and was wondering which mods will give the engine a better whole shot, and top end speed. I don't want to get into extensive performance wods such as heads and pistons,etc. Just stuff such as a poppet, ECU reflashing, lightened and balanced flywheel, stuff like that. Any advice would be greatly appreciated.