Another 2.0 vs 2.5 question

[Astro]

I have seen posts and replies on here that state a 2.5 150 will crush a 2.0 150 from low to mid power. My questions are this: one, are they about even on top end or can I turn a bigger prop with the 2.5? Second does anyone know how much more fuel efficient is the 2.5 efi 150 over the 2.0l 150? Maybe it is just my mota, but the 2.0 on my 18 footer is a thirsty little Merc.

[pyro]

Remember to keep things equal when comparing them. And also to those who reply, keep this in mind: 2.0 150's came with 2:1 gearcases, and 2.5 150's came with 1.87:1 gears. This is where much of the bottom end comes from.

[Astro]

thanks for the info pyro, i wasn't aware of the gear difference in the lower end. I hope this thread dosen't cause a heated discussion, as I am new to boating I figured I would ask you guys before spending hard earned money. My main reason for asking is that I have a chance to buy a 1999 efi 150. figuring the lower gear change with all other things the same the 1.87 gears should be good for 4 to 5 mph gain?

[Astro]

the engine that I am running now is a 1992 2.0L 150 merc with 23 trophy, bone stock, 1 inch below pad.

[Naiscoot]

I made the change from an 86 150 2.0 to a 95 150 2.5. The biggest difference I noticed is the 2.5’s ability to push loads better. It also seems to pack more low-end punch. It is easier to start, idles better, and is a good bit quieter. Overall a much smoother running motor. On the mileage and top end I don’t notice much between the two.
Good Luck,
Naiscoot

[Capt.Insane-o]

A bigger motor running easier than a little motor will almost always use less gas. A 2.5 will smoke a 2.0 out of the hole every time, no going to a 1.87 gear won't gain you any top end if you are already turning peak rpm and it is going to hurt holeshot. I like them due to they are cheap, tough, and easily found just about anywhere. But a 2.5 outdoes them in every manner, except for maybe the ability to take abuse.

[PropWash]

...and the sound. Those 2 litre motors sound cool.

I had a 2.0 150 and I swear that thing sounded meaner at idle than my 300x.

[Astro]

So, is the 2.0l 150 tougher endurance wise than the 2.5 150?

[T-REX]

yup...

[The Big Al]

So, is the 2.0l 150 tougher endurance wise than the 2.5 150?

NO!

2.0 litre is 30year old technology!

It's obsolete!

A stock 2.5 can kick it's ass.

Benn there done that.
They will move a boat. a 2.5 will move it better and faster.

[The Big Al]

thanks for the info pyro, i wasn't aware of the gear difference in the lower end. I hope this thread dosen't cause a heated discussion, as I am new to boating I figured I would ask you guys before spending hard earned money. My main reason for asking is that I have a chance to buy a 1999 efi 150. figuring the lower gear change with all other things the same the 1.87 gears should be good for 4 to 5 mph gain?

You are correct!

I would also bet the prop you are using now will be 1 or even 2 pitches short. Even with the gear change.


I had a 2.5 XR6 that blew, went to 150hp 2.0 and it was slower. Even on top end it was 10mph slower than the stk 2.5
Would not come out the hole nothing like the 2.5
This was power head to powerhead. same lower unit and gear.

And it did not last.

Went back to a 2.5 and very very happy again.

Al

[Capt.Insane-o]

thanks for the info pyro, i wasn't aware of the gear difference in the lower end. I hope this thread dosen't cause a heated discussion, as I am new to boating I figured I would ask you guys before spending hard earned money. My main reason for asking is that I have a chance to buy a 1999 efi 150. figuring the lower gear change with all other things the same the 1.87 gears should be good for 4 to 5 mph gain?


errrmm oops mis read that post. And yes it will be noticibly faster than what you have now.

[T-REX]

So, is the 2.0l 150 tougher endurance wise than the 2.5 150?

Well, in my deel'inz wit tha 2.0/2.5, tha answer to "TUFFER ENDURANCE WISE", tha 2.0 win's handz down!!!....Tha smaller, heavier pistons, thicker cyl walls make it a more livable mota...


2.0 litre is 30year old technology!

It's obsolete!

A stock 2.5 can kick it's ass.


All ov tha above iz basically tru, and tha behind tha liner configuration makes mo power, and if performance iz what ya want, tha 2.0 piston port mota iz OBSOLETE!!...BUT, if U want a dependable WORKHORSE, tha 2.0 kan't be beet!!!....A 2.5 piston kan't take tha abuse tha 2.0 piston kan...tha thiner piston castings in tha 2.5 will crack around the wristpin boss with exstended, abuse( abuse being harsh runn'in conditions)......A professionall crabber/fisherman down here in tha swamps will pick a 2.0 over a 2.5 anyday, and theze guyz put a motor to tha reel endurance test!!!

So, My answer to yo ENDURANCE question iz az standz...YUP!...Tha 2.0 iz tuffer than a 2.5.........Datz my story an I'm stikk'in to it!!;)

[Astro]

Hey thanks for all of the info guys!! Sounds like I need to go ahead with the 2.5 purchase. But after this thread I think I will keep the 2.0 as a spare! My boat will jump pretty good outta the hole with this 2.0, I can't wait to see what the 2.5 will do!!!!

[Chummy]

If you want to make a 2.0 run talk to T-Rex

[OntarioStreamin]

My uncle has a 2.0 on his 16 JCraft and the thing just hollars!

It been worked to sst120 specs and is by far the loudest outboard on the lake!
Its a handfull to drive too with the hand throttle and the crazy porpose!
Last I heard 65ish no jackplate stock lu and a four blade mirage:)

[j_martin]

Hey T-Rex
Where does the 2.4 fit into the scheme of things?

John

[Fish]

If you want to make a 2.0 run talk to T-Rex

I ws thinking the same thing. Very few if anyone in the country has as much been there done that as Rex.

[T-REX]

Damm, U boyz iz got me wayyyyy over rated....I will admit dat I kan take a good runn'in 150 HP 2liter and make a fire breeth'in 135hp outta it!!!....an cheep too!!!

Sum ov us juss gotta hang wit tha ole, outta date stuff...if'in I could afford a drag mota, I wouldn't have ta do all tha eat'in cast iron, an spend'in time wit tha grinder...Man gotta do what a man gotta do!!....anybody wit a good imagination kan take 4 or 5 2literz and make one dat runz good, wit a lil help from ya frenz;)

[airentrapment]

2 litre engines r very tough compared 2 2.5's, They r 10 to 15 pounds heavier than a 2.5, the sleeves are over 2 times as thick. We are an outboard machine shop and when a 2.0 block comes in it is as a rule not destroyed as with a lot of 2.5's, just be sure to let the engine warm up a little longer than a 2.5 as they are a lot thicker sleeves. Just my opinion. Micheal...Offshore Machine & Outboard...:D

[hydroholic]

The 2.0 ltrs are definately tuffer than the 2.5's as far as taking the abuse.I had a slightly modified 2.0 150 that spent most of it's time on back of my Vector @6800 +for a little over 3 years.Still was a runnin strong when I got rid of it. Person who bought it has since did a re-ring job (rings only,no bearings or anything else)and has it on back of a Varmint and just passed it's second year of use by him since the re-ring.Gets twisted pretty hard still and don't miss a beat.Just can't beat em.You dont see to many 2.5's that take that kind of abuse and stay together that long.Stock v/s stock the 2.5 may have a little more ump,but they are still pretty close to the same on the high end.I would choose reliability over that little bit of extra ump on the low end any day.As some of the guys up top said,T Rex can show you how to make them lil ole 2 ltrs feast on some of them bigger cubed motors.Hydro

[Astro]

Hey T-REX!! Got a question for ya!! Why is it when someone is half-arse they claim excellence? But, when someone is excellent they claim that they are are average to half-arse??:D Growing up, I watched my grandfather, who was an awesome outboard mech, do the same thing! Everytime someone would brag on him he would say that he just an average tech!! I just wish he here to see what he could do with this lil 2.0. Anyway, thanks to everyone for the replies to this thread. I will definately be keeping this mota around now. It is getting hard to resist the urge to put this old gal undr the knife to see what she can do! I am thinking next year, maybe a little hydorstream:rolleyes: and some grinding to see what she can do!!! Any thoughts on what kinda little boat this mota could be scary on when she is all fixed up?:D
larry

[T-REX]

U take & thro sum fingerports up in them lil cylz, raze dem pote'z up in tha 2.100" an 1.450 range, open dem exzaust pote'z ta bout 72% ov da cyl diameter, thro 200#+ squeeze, an a svs or MADD front on dat thang, PCU, 2:1 geer an a 22" yamadawg wheel, 1150#z ready ta run weight, an dat lil mota will sho ya 10K+!!!!....An a heavier bote betta have dem bad ole 2.5 pumped ta out run ya!!!.........Not bad fer a piston ported mota:D

Abote, lazer, streem, stv, marage, don't matter, long az it's LIGHT!!!

[j_martin]

Damm, U boyz iz got me wayyyyy over rated....I will admit dat I kan take a good runn'in 150 HP 2liter and make a fire breeth'in 135hp outta it!!!....an cheep too!!!

Sum ov us juss gotta hang wit tha ole, outta date stuff...if'in I could afford a drag mota, I wouldn't have ta do all tha eat'in cast iron, an spend'in time wit tha grinder...Man gotta do what a man gotta do!!....anybody wit a good imagination kan take 4 or 5 2literz and make one dat runz good, wit a lil help from ya frenz;)

Damn, T-rex, you're slippery.
The question was, oh great master of old iron, "Watz a 2.4 gud fer?"

Thanks in advance.

[rossi]

Hydroholic, mind me asking you what kind of speed #'s you were pulling with the Vector/2.0 ? If ya don't want to let the cat out of the bag...thats understandable. ;)

[T-REX]

"Watz a 2.4 gud fer?"


Well, it givez ya dat warm fuzzy feel'in, when ya kick a 2.5'z azz!!!!...

2.4.s are what rule bookz are based on!!!!....Ole piston poted mota's smoke a 2.5 an dey re-rite tha rule book, so makez ya stop an wunder juss how ole an obsalete dem ole junkz reely are:rolleyes: ......

U take an ole throw a way 2fo, cut it up, eat luminium till ya poo'in rivotz, cut stuff dat don't pozed ta work, an put it on a ole throw away bote, den kick a hi dollar 280 powered, hi dollar bote.....THEN U answer ya own question ov "WHAT IZ A 2FO GUD FER"!!!!

[Astro]

Sounds like the 2.4 has a lot of hidden potenial! How are they durability wise? are they "Better in the long run" like the 2.0's. Also how many revs can they take?

[Astro]

here is another question, I have had some people recently telling me that in the 2.0/2.4 days that the motas with grey paint were put together with heavier parts than the black motas? :confused: Does anyone out there know for sure?:rolleyes:

[T-REX]

motas with grey paint were put together with heavier parts than the black motas?

Datz BULLCHIT...tha only differnce wuz paint, and anuther outlet for mercury ta make money!!!....I know people dat didn't like Mercury's, hated omc's, so bought Mariners and luved them!!!,,,,Dahhhhhhh.........it'z a mind game!!

No, I wouldn't say a 2.4 iz more durable than a 2.0, kuz they ain't!!...Altho, tha 2.4 chrome mota'z were very tuff mota'z...They could handle stuff even tha nickle mota'z kan't handle!!...Tha 2.4's are capible ov 8000+ rpm's in stock form(with a 1250# boat, and rite set up)...Practikle use would be 6000-6800 wit a ski type bota, and river set up...Tha 2.5 will have a tad more grunt out tha hole(in sum cases), but I have outrun 2.5's wit a 2.4, and I had tha heavier boat!!...

I'm not sell'n 2.4's, 2.0's, or 2.5's...This iz juss my opinion based on tha deel'inz I,ve had with theze mota'z........I quess tha moral ov tha story iz...If U got money, buy a 2.5....if U got more time than money, use what U have...tha more time spent exsperimenting, the more HP U kan uncover from any ov theze mota'z.............REX

[j_martin]

So I'm not dreamin' when I blink and miss the hole shot with my old XR4 bone stock almost on a 18 year old bass bote. Damn, this is fun.

What's the difference between 1988 XR4 2.4, and 1999?

[T-REX]

What's the difference between 1988 XR4 2.4, and 1999?


Well, a XR4 iz az U said a 2fo, and iz rated at 150HP...But, will put out 10 or so more HP than a std 150.....They don't have a XR4 in 1999, so a 150 could be a 2.5, or a 2.0!!!....I'm not sure what yeerz tha XR6 made tha scene, and when it leff, but tha XR6 wuz a 150 2.5, and az tha XR4, made a few more HP than tha cover displayed!!!.....150 HP iz 150HP!!!!......whether it be a 2fo or a 2.5...but, tha 2.5 will have more torque than tha 2fo, partly kuz ov CI, and partly kuz ov tha port configeration(behind tha liner)...

[j_martin]

My 2.4 was accidentally cc'd, I think. The previous owner had head trouble a couple of years ago, and one head has the yellow junkyard ink on it. Compression is 145psi at cranking, open throttle. I think that should be good for another 10 or so. It idles a little rough, probably needs carb cleaning and the foam floats changed in the 18 year old carbs, and the bleed line check valves examined. Might as well change out the old metal reeds to fiber before I suck part of one into the motor. I wonder if I should change the tuner.
The old boat is still stuck to the lake goin' 'bout 60. Maybe it'll jump up on the pad and cut loose if I get the moter tuned a little.
I think the Merc "premium" oil gotta go, also. I'm thinking Alisyn ProPower. It's a little smoky and likes to coke up too much now.

Thanks for all the info
John

[Slickone]

Hi John,

By all means John, please try our Alisyn ProPower. I'm sure you've read the posts on screamandfly site. It is the benchmark 2 cycle oil, and all S&F members get free shipping.

While you're at it, also try our ProGear Type I or Type II lower unit oil.

Please call me at 614.878.3600 if I can answer any questions.

Best regards,
Jerry Manastyrskyj

[Astro]

Found problem on engine!! Well, one of the problems at least. It was a very small diameter hose from the middle carb to an elbow fitting in one of the cyl walls! when running this thing was steady pouring gas. Replaced Hose. Does anyone know what this hose was:confused: anyhoo I have a question since the 2.4 was mentioned. Ok, the first black max was 175hp in 1976. I am pretty sure it was a 2.0L. was this rating at the powerhead or at the prop? Kinda seems like it was a powerhead rating. From what I can find out within a year or two the 2.0L was a 150 and the 175/200 was a 2.4.

[dynobo]

Sounds like a recirc. line. Basically just recirculates unburned fuel in cylinder to keep it from puddling. Yep, the original 2.0/175's were powerhead rated. Later 175's were 2.4 200's with vertical reeds and different carbs.............:D

[j_martin]

I gots a 1988 Black Max 2fo wid 150 stikkerz on it. i been told dat itz a 175 at the hed, and bout 162 at da screw. all I know iz dat it goz lik a scalded dawg. I tink de XR4 wuz mad inta 1990. Itz a 2fo on a 4 inch geerbox. Da XR6 is a 2five on a 4 in geerbox. XR4 is 1.78 geerz. I also no i been tryin to reed T-rex too much.

Is the line you're talkin about one of 5 or 6 similar lines? If so, its a bleed line with a check valve on it, and a stuck check valve will run rich.

hope it helps
John

[Astro]

Are the check valves in the 90's at the back or at the carbs on the front? I am asking because my 150 does tend to run rich on idle, actually it is very mean to crank and keep running. also how can I check to make sure all are working?

[j_martin]

Look up your serial number in mercurypartsexpress.com Select the reed block and cylinder head diagram. You'll get the picture.

The check valves are at the front. They are easy to check with a small plastic syringe. (without the needle) They should only allow flow one way. It's about the first thing you check for rough idle. Crappy leaky lines make for rough idle also.

I'd check the carbs out. Are they mounted in the right place? (they can be different.) Are the floats sunk? (if they are the old foam floats, replace them.) Is the float drop set right? Needle and seats in good shape? Jets correct and correctly installed? (Look in the chart in your service manual) If you're flooding it's gotta be coming from somewhere. The bleed system just handles the little bit of puddling (flooding) that is normal, and recycles it back into the intake system.

Hope it helps
John

[Astro]

Finally got recirc lines routed right. Had to go buy book for mota. Every one of the recirc lines was in the wrong place:mad: checked the check valves and sure enough all but one of them were stuck. Ran boat yesterday and big difference bumped it twice and purred like new motor:D :D . Also I must have been loosing allota gas thru the broken line cause I got 2times the mileage yesterday wooohoooo!! but still slow:(

[j_martin]

Hey Astro, I got a motor that was screwed up somewhat by a mechanic that couldn't read, or maybe just didn't give a damn. Anyway, everytime I investigate something, I find it a little off, fix it, and it picks up a little oomph. Use the winter to check carbs, timing, etc. You might just be pretty pleased.

When I got this thing, it was kinda doggy. Now, I'm thinkin' the limit is likely to be testicular shrinkage, but when I put it back down a little and slow down a little, I think it'll be a real nice family motor.

John

[dompie99]

Hi y'alll

Happy new year to all of ya

As for this thread, the 2.0 L has my vote abuse wise....

after the advise of T-Rex, i made mine rev up to 7200 without hesitation, and have to brace myself to the steering wheel with a 28 pitch chopper on a Hydrostream crazy boat....it suks fuel on a steady basis and got ride of the oil pump...feed it with 30:1 premium fuel and never busted anything for almost 8 months so YES T-Rex is right.

[Astro]

Hey, gotsa question. How the heck are yall making the 2.0 turn more than 5k? there has to be a rev limiter on my engine somewhere?! The guy that I paid to butcher my engine stated on the receipts that he set the rpms to 5200. I wish i knew what he did, cuz no matter what prop I try she won't rev up over 5100rpms!!! can someone advise?

larry

[dynobo]

If you're still running the 92' 150 then I would be interested in seeing how he SET your maximum RPM to 5200. I think he's blowing smoke. Unless you have a timing advance box that is reducing the timing at those rpm's then I don't see what else could be doing it. Have you checked fuel flow to make sure you are not running out of fuel on top?

[Capt.Insane-o]

There is no rev limiter, Unless he has severely retarded the timing or purposely botched the jetting. I've run 2.0's on vipers and vectors for awhile now in warmed up form at 7000-7200 for a reletively stock motor.

[Astro]

I bought rebuild kits for carbs. everything is by the manual, jetting is exact with the book (wh-1), i havn't been able 2 check timing yet but I am buying a timing light tomorrow. as far as this guy being full of it, i agree:D this guy is something else, I took it to him to tune it up and make sure everything was ok when i bought the boat, 1200.00 and 3 months:eek: later it ran worse than it did when i bought it:mad: this jacka$$ even tried to charge me $5 a day for storage fee for the 3 months!!!!!

any tips or tricks to make timing this mota more simple?

THANKS IN ADVANCE :D FOR ALL THE HELP GUYS!!!!!!!!


LOL, SORRY COULDN'T HELP THAT ONE, TALKING ABOUT TIMING AND ALL!!
LARRY

[Astro]

OH YEA, FORGOT TO MENTION. THIS THING IS HORRIBLE ON GAS. iT isn't as bad as it was before i got the recirc hoses right. idles loads better. still getting about 1 mile per gallon! this thing has to do better than this? could timing being off do this?

[Capt.Insane-o]

I'd find a dealer you can count on for a fair synch and link. There is a dial indicator check for the timing mark, and then a couple other adjustments to the throttle linkage and trigger arm to check. I'd look at the fuel pump too to see if that is all straight as well.

[j_martin]

I agree, sounds like the fire is racing like hell to keep up with the pistons.
One thing I've heard of more than once is the wire harnessing keeping the trigger from going to full advance. The wires get a little stiffer on these old motors, and it kinda sneaks up on ya.

hope it helps
John

[Astro]

checked timing today. idle on this engine is around 1k. in gear around 800. idle in gear timing is 8atdc. and at full throttle is 10atdc. I have heard that it is a pain to set up the timing? any suggestions?

[dynobo]

The idle timing isn't a major concern if it idles normal. I would think your WOT is not 10ATDC because it wouldn't even get on plane. Even at 10 BTDC I doubt it would rev to 5K. I would find a Mercury tech. and have him look at it. Sounds like you definitely have an issue with the timing.

[Astro]

looked at a mercury book last night and wot timing is supposed to be 19BTDC. I am loosing a few degrees what the book says. Ok, any of the Mercury gurus please advise on what the best setting is for stock 2.0. Is the book right?

thanks

larry

[T-REX]

If it wuz me, I would dump tha time'in module(if so aquiped) and set tha top end time'in @ 24*....Close ya butterflies completely, and use your bottom end time'in to git the prefered idle U want...But, thats juss me!!

[Astro]

23* timing:eek: will my mota really take it safely? what ill effects will I have to deal with? Should my pistons be scared of holes at that degree? How do I remove the module?

heres a question or two for ya T-REX:cool: If you are sure it will take it I will make it happen.


larry

[dynobo]

The 150 should take 23 degrees with no problems. You should definitely notice a snappier holeshot and better topend. Make sure you do away with the timing module if you still have it installed.

[T-REX]

23* iz a piece ov cake fer a 2liter mota!!!!.....I set all tha Prop stop work mota's @ 24* wit factory jett'in!!!!....Other than hiz employee's that are dummer than rocks, an kan't find tha place ta check tha oil on tha mota:( , I don't have any problemz!!!

[j_martin]

Slow Astro,
The timing numbers you gave don't make sense, so something is wrong. Be sure it isn't you that is wrong. Setting timing way off could be fatal to your engine.

Go by the book. You must check the timing marks with a dial indicator, or you can get by with a caliper using the probe end. Then set the timing at cranking.

The throttle linkage directly moves the timing pickup, called the trigger. It is spring loaded. Old stiff wiring, old weak springs, or someone laying up wiring or tubing that interferes with it will affect the timing. Seen it on my motor. Make sure everything moves freely.

Mercury has several versions of "timing" modules that supposedly stabilize the idle, retard at high speed, advance at high speed. I don't think they carry any of them anymore, because they work best in the chit can. Any 2 or 3 wire black box that is connected to the switchboxes is one of these modules. Look at the wiring diagram in the maintenance manual.

If you don't have a maintenance manual, don't do anything or ask any more questions till you get one.

hope it helps.
John

[dompie99]

Hi t_Rex.....

By the way, got the engine running FINALLY.....not now ( in Canada there is snow now a days )

I did most of your mods on the engine BUT still some more to be done


Thanks

[T-REX]

Glad ya got it goin!!!....Now go out and melt sum ov that snow:D

[Astro]

mota doing better, ticked a little at 23* soooo I backed it down to 21*. Made big difference removing box. Question: what about the 3 wires that run directly into the epoxy in the bottom, can I cut them as well or do they have to stay intact?

larry

[Dave S]

The Next thing T REx will have Ya doo is Mill the Heads 1.000000 Good for compression.:D Not much left over .:rolleyes: