differences between 2.5EFI's

[vishus]

I remember seeing something awhile back, but can't find anything specific in searching the forums....

I was wondering if anyone has a decent history of the different 2.5EFIs from the 1991-2--curent 2.5 280.

I was looking for info like
:when were the ECUs analog vs digital.
:rev limits on various models
:when did they go to Sportsmasters
:what is the main diff between OS and STD? is it just tuner/exhaust snout and higher rpm limit (was this on ALL OS, or just some years)?

and LAST but not LEAST, which PRE 2.5 280 was BEST and WHY?

I wish someone (hint to US1, JaySmith, JT Jr., GREG) would make a book on the 2.5 and its variations. I would also love a book like my I had in High School when I was RACING my 240Z ("How to hotrod and race your Datsun"). That book was great, it taught you the BEST combination to create a GODZILLA motor for the Z car. Take this year 280Z block, run the 240Z heads, this type of cam, take a 5spd out of the 280ZX, run the Maxima automatic rearend (Higher gears than available in any Z-car), etc. etc.... NOW that was a GREAT CAR book.

I want a GREAT OUTBOARD book.....

thx.sid

[randy 77zt]

i would buy a book on merc 2.5 efi history/parts exchange .i bought a mirage used and found out it had a 96 2.5 efi motor on an old 2.4 mid and lower.a merc technician looked at it and said it had a offshore ecm .so i got a boat with a mutt motor.from what i have heard 96up has a bigger bearing on top of the crank shaft that is more desirable.and i have a 77 280z with a 81 turbo engine in it.nissan didnt change parts as much as merc.maybe if 1 of the members on this website that is in to mercology printed something up it could help out on his outboard drag race season funding.

[pirogue]

you may find some useful info here!

http://www.biggerhammer.net/mercury/

[us1]

I'm not ignoring you my old brain get the dates mixed up so I don’t want to make a fool of myself.:D

[vishus]

John,

you always have GREAT responses, this is just a subject I wish SOMEONE would tackle. I would PAY to buy a book on the subject, it would make a great reference for anyone playing with the 2.5 series of motors....


thx.sid

[luv2gofast]

I just bought a 280 (which I will soon be rebuilding) and was about to ask the same questions. I am interested in reliabilty, required octane, RPM limiters, head cc's and design differences in the 2.5 series motors. I am also looking for the pro / con on CLE verses sportmaster.

Thanks guys,
Great board!

Bob

[us1]

Thank god, someone else from So. California.:cool:

[luv2gofast]

Yep! Hard to find a hot rod outboard to race around here! And the jets are gettin' smart and won't go for a run with an outboard anymore. All my friends have flaties and I/O's. I have always had outboards... guess I was born on the wrong coast for hot boating.

[vishus]

You got that ebay 2.5/280, didn't you? that should run well once you have it back together.

There are a few of us Outboards in AZ that run pretty good. Most of the squirt boats are used to racing bassboats (not Allisons/Bullets, more like Rangers/Tritons/Champions), so they can't understand how they lose to someone running a "Fishing" motor.

I having been running a warmed up 200XRi, but 90mph was stretching it (as in the rod went througth the side); really wanted to go with a US1 MODU, but I am going to stick to a stock 2.5EFI for now, should run O.K. on my RIOT...

I plan on making a few trips to Havasu/Speed Alley to see some of the SERIOUS outboards run this year.

sid

[blkmtrfan]

There are a few more outboarders up here, at least realatively speaking (not really that many hot boats up here) compaired to the car motor boys ;)

[STVBOY]

There are plenty of us out here with outboards but you don't seem to make the events that are out here with your silverwing.Would really like to see you make it out to the BBSP in April it is a good time.


Vishus hope you can also make it to the BBSP with your riot would be a lot of fun to see several riots runnin out there.Good luck on the motor. Thx John

[luv2gofast]

Looks like we got off the subject! Oh well where is the BBSP meet in April and how about a web site?

[vishus]

BBSP

4-24-04

my Riot is just a fun lake toy, but there is at least one RIOT that is serious ....current king of BBSP is UT in a little ol' RIOT with a 2.5 with laughin gas....

He may have a surprise or two this year.....

check out this thread for a little bit of the pre-event smack talking...

http://www.hotboat.com/forums/showthread.php?s=&threadid=34392

[randy 77zt]

will be at bbsp.been there for last 2 years.probably the best outboard get together west of the rockies.i think i heard ut got a mirage or something.i have never seen ut really stand on the throttle.last year a 4 seat mirage with a drag 300 and spray cleaned up.i know 2 guys from norcal getting ready right now.my boat is getting offshore mid put on .

[us1]

Do you have any pictures of your boat?

[vishus]

UT has Barney's old Mirage. Single seater, lighter than the RIOT, quicker in the 1/4, though not as good in the rough....

should be FAST...

[luv2gofast]

I need some new pics!

[luv2gofast]

Any one remember what a Baker RST is? Bottom is like a Stoker.


STVBOY,
Can't make the BBSP this year (don't look like a 70 MPH ski boat would be much fun anyway!) Any guesses what my girl should do with the 280? I run a 28 chopper at 5800 with the old 220 @ 70. I have no idea what it weighs

[CrazyHippy]

I had fun w/ my ski boat last year. More about fun than racing.

BJH

[luv2gofast]

Looks like a great time! I was lookin' at the smack on the link vishus posted. If I was free I would be there. I have to work at a car race in Vegas that weekend.

Racing always gets in the way of racing and then I go racing between races.

Bob

[vishus]

Luv2gofast,

nice looking classic MODVP hull!!! You should contact DSWARTZ (user name on Screamandfly), Don is a GREAT guy with a GOOD running RST. He has had it since new, and knows it like the back of his hand, he often fishes out of a Baker Tunnel bassboat, so he can steer you right in the nuances of the Baker, by the way, he is running almost 90mph in a RST with a 225Johnny...

Look for the March issue of Hotboat, his RST is in the reader rides!!!

way to go DON!

sid

[luv2gofast]

I sent Don an e-mail. I have seen a few RST's over the years but most of the owners have no idea of the history or how trick this hull was when it first came out. It is the best handling boat I have driven. (not that I have driven many) But it dances over nasty chop at 70 like nothing and turns like it's on rails!

[us1]

It looks good.

[luv2gofast]

So what does your crystal ball say? What do you think it will do with the 280? And back to the thing that attracted me to this thread... Is a 280 a good choice. I see in the shop manual it should run on 92 octane and it says max RPM is 7500. I know if I run it all day long at 7500 it will wear out 10 times faster than my 220 at 5800. I guess I just want an opinion on how the 280 will work as a ski / race a few jets / idle up the narrows at Nacimento type motor on my boat? That is my typical boating day.

[us1]

The 280 is a great motor. I prefer the 260 because I like the electronics better. If you never want to modify the 280 the electronics it comes with will work fine. Any of these race motors will ware out the rings by 100 hours. As a ski motor the 260 and 280 are great. Top speed will depend on set up and boat weight but 100 sounds good to me. :cool:

[luv2gofast]

That's what I wanted to hear. I don't have any problem buying sets of rings. If I get 90 I should be jumping up and down (at least till I get used to it). :eek: :eek: :eek: :D :D :D :D

[luv2gofast]

Funny how a search brought be back to a thread that I havn't seen since 04. Well I gave up on putting the 280 on the Baker. Never seem to have the time. I did get another tunnel that has a 280 con on it so now have some questions that are relivent to this thread so it's back...

What is the difference between a 98 280 ROS and a 01 280 CON. I have one of each now. The ROS is the one I got for the Baker but never got around to rebuilding it. It needs a sleeve in one hole. The CON is on my new (98) Lavey and I had it out for the first time last weekend. I checked it with my DDT last night and it has 120hrs total with only .2 over 7K and 12hrs between 6 and 7. It has a 7750 rev limiter so I guess it's over proped or the last owner never pushed the right peddle. Does the "100 hours, needs rings" still apply when it not run at high RPM's? I would think it has some time left due to so few hours over 6K.

Bob