Omc 3 cylinder comparison

[PIP]

My 13 Allison (1972) is being restored as I get time, transom, core, the whole shabang. I have a question;

I have an old (1980 ish) 75 OMC, not a nitro-cased motor and it has always been preached to me that it would be best to have a nitro motor, due to the 15 inch mid, as well as, narrower gear case. It is also my understanding that the later 56 inch race motor, is even better, but my question is; if I cannot readily purchase an old nitro motor, or a later racing 56 incher, wouldn't the standard later 56 inch, 70hp motor be better than what I have, and as far as top end goes, wouldn't it also be better than the 49 inch nitro motor, simply because it puts out so much more power?

I am cost consious and not doing any sanctioned racing, but like to go fast. It simply seems that their is no good reason for me to spend $2,000 on a good nitro 49 incher, if i can pretty easily spend, $800 on a good, late 1980's 70hp that is "faster" still, though it will lack the 15 inch, on top end, I see this making little difference.

Thoughts please?

[David Mason]

I think you are doing the right thing going with a later model 56 CI. More punch for the bigger boat. Should be a decent rig for a lot less than modifying a 49CI.

Good luck with your project !

[Ron Hill]

Can you tell me how you know you have a 56 incher? Is there a serial number ID to look at? I want to buy a 56 incher.

[Travis Fulton]

the 56 cyl head is flat on top, the 49 has cut outs where the plugs go

[Phil McDaniel]

Ron, Even though the cranks will interchange as well as the carbs and ignition(with a little modification to flywheel for trigger) and also the front half/reeds will fit, the block and head are diff. With those two differences the rods and pistons will not fit the 49 in their stock form. Other than the 3.187 bore of the 56, you can also identify the block by not being able to remove the exhaust cover and have access to the ports. The 56's are "behind the liner" intake and sleeve set-up.Port timing will also be diff. than the 49.Other than the block-head-pistons-rods-powerhead adapter plate, everything else can be made to work on the 49. Phil

[Phil McDaniel]

Forgot to mention the diff. in the cranks. ---Earlier motors had 4 spline cranks as did/does the 49. Then they started with a 17 spline crank. All were forged. I understand from the SST60 guys that some earlier ones were lighter in stock form. Phil

[Powerabout]

all the 15" cranks are 4 spline and the 56 20" are fine I think
( or maybe they changed to fine not long after they introduced the 56)

[Mark75H]

Which ones have the lost foam castings that look like the motor is made of painted styrofoam?

[mxp864]

the 56" from, i think 88-92 look like black foam....I think those are the years......

[Powerabout]

the 56" from, i think 88-92 look like black foam....I think those are the years......
The 56 is a lost foam engine, thats one way to identify it.
Cylinder head is one piece, exhaust is integral to the block
49-75 was still being produced when the prop rated 56-70 came out so 86-88 you could get both
EDIT sorry 56 came out as lost foam and perma mold

[TBuck2003]

56 for sure has more grunt. As far as set up ,and performance the short mid with the nitro case is the way to fly. The big case on that boat does not run well, and the long shaft hampers set up. Have same boat with 49 ci with shorty and Nitro case. Pic is in my avatar. My .02

[Ron Hill]

I think I have made a deal to get Bunker Hill's old three banger from Mickey Schwarzenbach form Apple Valley Marine.

I'm not talking about my "PROJECT" here, but do want to know how much performance difference there is between the 49 and 56???

Second part of my question: Anyone know how many 49 ichers were made? And how many 56 inchers were made???

[Mark75H]

IF anyone knows, its probably Edgar

[TBuck2003]

I am in need of some 56-58d jets for a 1976 Evinrude 75 "S" short shaft. I think they came with 55d but that is at 16* timing. PLEASE send a PM or respond if you have any or know of any...Thx

Todd

[Roy Hodges]

Back in the day, (1975) Tom Ireland ,after much trial &error, came up with optimum settings for the 75 (short shaft ) in closed course competition. 1 step leaner jets & 3 MORE degrees timing ;19 degrees before tdc.He also said that you must be propped to turn 7000
R P M or you won't be competitive......the early 1975 75horse motors came with a higher compression head than than 1976 motors. check the parts lists. there was also a higher compression head (optional) available and legal for the Sport E tunnels &family E runabouts.
I am refering to about sea level altitude.

[mercmack]

All you need is a real omc factory service manual..in the back of section 2 or 3 they list all the jets they used in all there late model motors ..it has the jets size and the part no that goes with it....a parts list will give you the part no for the standard jet then use to s/m to pick out the jet you want and order it from any body that can get omc parts..:d

[Roy Hodges]

[QUOTE=Roy Hodges;96564]Back in the day, (1975) Tom Ireland ,after much trial &error, came up with optimum settings for the 75 (short shaft ) in closed course competition. 1 step leaner jets & 3 MORE degrees timing ;19 degrees before tdc.He also said that you must be propped to turn 7000
R P M or you won't be competitive......the early 1975 75horse motors came with a higher compression head than than 1976 motors. check the parts lists. there was also a higher compression head (optional) available and legal for the Sport E tunnels &family E runabouts.
I am refering to about sea level altitude.......................................... .................................
.................................................. .................................................. ................................
.................................................. .................................................. .................................After checking my notes from Tom; he said ".059 main jets are optimum &of course the 19 degrees before tdc timing." (sea level) These settings are for a legal stock 75 Hustler.

[phillnjack]

Here is a pic of a 56 head with the flat for the plugs like mentioned above
as for the head and water jacket being one piece, the water jacket does look like it should come apart, but it dont.
the thermostat housing also different to 49in
below is a pic of the head on my 56 in, on a 1995 evinrude engine.

51271

phill..........:cool:

[Smokin' Joe]

Old post but so what. Not much hp difference between 49.7 and 56 c.i. powerheads,
far more speed difference in nitro vs clubfoot gearcases. The later
are geared so low you can't make them run.



My 13 Allison (1972) is being restored as I get time, transom, core, the whole shabang. I have a question;

I have an old (1980 ish) 75 OMC, not a nitro-cased motor and it has always been preached to me that it would be best to have a nitro motor, due to the 15 inch mid, as well as, narrower gear case. It is also my understanding that the later 56 inch race motor, is even better, but my question is; if I cannot readily purchase an old nitro motor, or a later racing 56 incher, wouldn't the standard later 56 inch, 70hp motor be better than what I have, and as far as top end goes, wouldn't it also be better than the 49 inch nitro motor, simply because it puts out so much more power?

I am cost consious and not doing any sanctioned racing, but like to go fast. It simply seems that their is no good reason for me to spend $2,000 on a good nitro 49 incher, if i can pretty easily spend, $800 on a good, late 1980's 70hp that is "faster" still, though it will lack the 15 inch, on top end, I see this making little difference.

Thoughts please?

[phillnjack]

well i have to disagree about the 56ci not being much more power than a 49ci.
ive had both 49 and the 56 inch motors both 60hp versions, i find the 56ci to be a lot more powerfull and responsive.
maybe its just the two engines ive owned ?

what exactly is a nitro and what is a clubfoot ? coz i dont think we get them over here.



phill

[Smokin' Joe]

Maybe on a fishing boat. Not much difference on tunnels, mainly punch.

[phillnjack]

wouldnt have a clue about tunel hulls, ive always prefered a proper boats.ha ha
dont fancy the idea of a tunnel, they seem like 2 canoes and a seat with engine strapped on doing crazy speeds.
I like to watch them run , love they way the drivers get them to float on a cushion of air right at the limit.
But i dont think i would be any good at driving one of those, i think they are way out of my driving skill ability.
The guys who drive those tunnels are very good at what they do.


phill....

[Ron Hill]

There was a time when people had a disability and walked with a limp, that they were said to have a "CLUB FOOT" because their foot was disfigured and gnarly to look at, people began calling a "STOCK PRODUCTION GEARCASE" a "CLUB FOOT" because it didn't have a point and was
UGLY". . Racing motors had sleek, pointed "lower units" (No gearcase in the old days, they were Lower units, and that is where the prop went on). When Mercury Outboards first started racing, there were no "QUICKSILVER" lower units. When Mercury made the QUICKSILVER" (Lower unit) they called it a foot. (A Quickie Foot). Mercury Racers didn't want to be associated with the OLD Johnson and Evinrude (Alky) Racers. But neither did the Johnson and Evinrude OUTBOARD RACERS want to be associated with those "DAMN MERCURIES".....They were never Mercuries in the eyes of the old "ALKY BURNER" Racers, they were "DAMN MERCURIES".

So, when the guys started switching over to the "QUICKIE FOOT" the old gearcase (lower unit) got the name "CLUB FOOT" because it looked like a person with a handicapped foot. Some people tried to say the "CLUB FOOT" was for Yacht Club Racing...and was for "CLUB" racing, but that was never the truth.


A "CLUB FOOT" is any gearcase that isn't built for racing...

I do think, that now days with bottom water pick ups, a "CLUB FOOT" can be made to go very fast with the right prop, which is usually much larger in DIAMETER and in BIGGER in PITCH than a Stock prop.

For the OMC three bangers, there is the Nitro Case, which is like 3 1/4 in diameter and the "REGULAR "CLUB FOOT" (Nitro is a "CLUB FOOT, too). Regular gearcase has a diameter of 4".

[Smokin' Joe]

My good friend Ron, may i disagree somewhat?! I'd say that the Nito gearcase is not a clubfoot. The 1960 Mercury gearcase
is not a clubfoot. The fat, low geared Mercury 1957-60 60-80 hp 2:1 gearcases were clubfoots, so were the fat, low geared
(2:1 and less) OMC 60, 70, 75 longshaft gearcases of the 1970s and 1980s. The Nitro and Sportsmaster gearcases 'ran',
they were streamlined, relatively small and relatively high geared.



There was a time when people had a disability and walked with a limp, that they were said to have a "CLUB FOOT" because their foot was disfigured and gnarly to look at, people began calling a "STOCK PRODUCTION GEARCASE". Racing motors had sleek, pointed "lower units" (No gearcase in the old days Lower unit is where the prop went on). When Mercury Outboards first started racing, there were no "QUICSILVER" lower units. When Mercury made the QUICKSILVER" (Lower unit) they called it a foot. (A Quickie Foot). Mercury Racers didn't want to be associated with the OLD Johnson and Evinrude Racers. But neither did the Johnson and Evinrude OUTBOARD RACERS want to be associated with those "DAMN MERCURIES".....They were never Mercuries in the eyes of the old "ALKY BURNER" Racers. They were "DAMN MERCURIES".

So, when the guys started switching over to the "QUICKIE FOOT" the old gearcase (lower unit) got the name "CLUB FOOT" because it looked like a person with a handicapped foot. Some people tried to say the "CLUB FOOT" was for Yacht Club Racing...and Was for "CLUB" racing, but that was never the truth.


A "CLUB FOOT" is any gearcase that isn't built for racing...

I do think, that now days with bottom water pick ups, a "CLUB FOOT" can be made to go very fast with the right prop, which is usually much larger in DIAMETER and in BIGGER in PITCH than a Stock prop.

For the OMC three bangers, there is the Nitro Case, which is like 3 1/4 in diameter and the "REGULAR "CLUB FOOT" (Nitro is a "CLUB FOOT, too). Regular gearcase has a diameter of 4".

[phillnjack]

well i i think ill stick with my stronger club foot gearbox.
smaller gearcase i can understand is quickerthrough the water though.

but atleast i now know ive got a big club foot ha ha

phill

[Powerabout]

if you only use twin pinion lowers then I guess everything else is a club foot?

[Ron Hill]

My good friend Ron, may i disagree somewhat?! I'd say that the Nitro gearcase is not a clubfoot. The 1960 Mercury gearcase
is not a clubfoot. The fat, low geared Mercury 1957-60 60-80 hp 2:1 gearcases were clubfoots, so were the fat, low geared
(2:1 and less) OMC 60, 70, 75 longshaft gearcases of the 1970s and 1980s. The Nitro and Sportsmaster gearcases 'ran',
they were streamlined, relatively small and relatively high geared.

Most "Alky" burning outboards and Modified Stock racers use a "HATCHET" gearcase anymore..........and they don't have a point. They are made for racing. A Yamato Motor was made for racing, and it doesn't have a point......So???Usually, I refer to any gearcase that shifts as a "CLUB FOOT". I figure "Race" gearcases don't shift!

[phillnjack]

is a 1995 omc triple considered a strong engine to work on for making a touch more power ?
is the gearbox a strong box ?
ratio's i wouldnt think make much difference as the prop is the real ratio decider surely ?

phill

[Smokin' Joe]

Wrong about gear ratio. A big dia. high pitch prop always creates
more drag than a small dia. low pitched one. Ditto for
a big, fat gearcase.





is a 1995 omc triple considered a strong engine to work on for making a touch more power ?
is the gearbox a strong box ?
ratio's i wouldnt think make much difference as the prop is the real ratio decider surely ?

phill

[Ron Hill]

Wrong about gear ratio. A big dia. high pitch prop always creates
more drag than a small dia. low pitched one. Ditto for
a big, fat gearcase.

In theory maybe, but a 1:1 Mark 20-H compared to a 13:19 20-H, Big prop goes faster than the 1:1 and out accelerated it also. In the PRO Division we never ran 1:1 and the 15:16 was quicker and just as fast. A big prop turning slow moves a lot more water. On our COR Boats the 2:1 is quicker than the 1;86 and close to the same top speed, but around the short course, the 2:1 is best....

You are telling me a 10 X 20 will be better on a Sport C that an 11 X 18??? Or a 9 X 22 would be better yet?

[Smokin' Joe]

I'm thinking of fishing gearcase vs Nitro or Nitro vs quickie.



In theory maybe, but a 1:1 Mark 20-H compared to a 13:19 20-H, Big prop goes faster than the 1:1 and out accelerated it also. In the PRO Division we never ran 1:1 and the 15:16 was quicker and just as fast. A big prop turning slow moves a lot more water. On our COR Boats the 2:1 is quicker than the 1;86 and close to the same top speed, but around the short course, the 2:1 is best....

You are telling me a 10 X 20 will be better on a Sport C that an 11 X 18??? Or a 9 X 22 would be better yet?

[Hounddog]

We have been running both the 49's and the 56's in T class [V bottom EP style Critchfields] here for several years. Stock to stock a 49 stinger is faster. In a LeMans start the 56 is off the dock faster, but the 49 will run it down, We revised our rules to increase the performance of the 56 because they are newer motors and there are more of them. The rule was simple. You can run 160 compression head on that motor. That increases the compression from 120 to 160. Basically we allow you to put an SST 60 head on a fishing motor. That change makes the two motors competitive.
The 56 now has the extra top end to run with the stinger. It can be even better because it does have more punch out of the turns. All our motors are 15 inch nitro or SST 60 gearcase. They run 66 to 70 mph on the oval.

[phillnjack]

now when you say stock you mean straight from normal everyday marine shop with no mods at all!!!!!!!!!!
or are we talking some mods ?
because i cannot see omc re-tooling costing absolute fortune just to make a slower engine.
the fastest of any outboard and winning means more sales to the public with boat engines.
now i thought the johnson stinger was 75hp at the flywheel, and todays engines rated at prop.
this would make a stinger around 65hp if your lucky.
No way were the stingers faster top end then a mercury 70hp in the uk.dont know about usa, but the stingers over here were slow compared to mercury 3 cylinder.
all the orange stingers ive ever come across were just used for ski-ing as they were slower than normal engines
but good for ski-ing
The stingers were promoted in the uk to be good for water ski-ing,never seen anything about them being fast top end.
it sounds like a lot of engines in the states are totaly different to what we get over here.
mercury dominated the uk for a long time with the 3 cylinder engines.

strange that you say they will be equal or even faster than the 56ci motors.

what happened to make the 56ci so much less power ?


phill

[Powerabout]

so what the 56ci needs is some mods not quite to sst60 spec so it retains its bottom end but a bit more up top
chamfered exhaust ports like a 75?
But if you want close racing sounds like Hounddog has got a solution

[phillnjack]

maybe the orange things with 75 stinger on them over here in uk were all just crap and sold as a gimmic.
coz they sure were not fast compared to most others around.

now the sst 60 i have no idea about, never seen one in the flesh.
I take it these are proper engines similar to motorcycles that push out over double what outboards do for
the same cubic capacity.


phill

[88workcar]

My 13 Allison (1972) is being restored as I get time, transom, core, the whole shabang. I have a question;

I have an old (1980 ish) 75 OMC, not a nitro-cased motor and it has always been preached to me that it would be best to have a nitro motor, due to the 15 inch mid, as well as, narrower gear case. It is also my understanding that the later 56 inch race motor, is even better, but my question is; if I cannot readily purchase an old nitro motor, or a later racing 56 incher, wouldn't the standard later 56 inch, 70hp motor be better than what I have, and as far as top end goes, wouldn't it also be better than the 49 inch nitro motor, simply because it puts out so much more power?

I am cost consious and not doing any sanctioned racing, but like to go fast. It simply seems that their is no good reason for me to spend $2,000 on a good nitro 49 incher, if i can pretty easily spend, $800 on a good, late 1980's 70hp that is "faster" still, though it will lack the 15 inch, on top end, I see this making little difference.

Thoughts please?

If you are not partial to the OMC, I know you have one to start with.... Sell it a go with a 90 Yamaha, great power, great prop selection. And no it is not too big or too heavy. If you think so, what about a 70 Yamaha? On either engine a short shaft is easily attanable and so is a small foot lower unit. On either you can use a 40 lower unit. The parts are still very available and you will have a current style engine. The 70 can quite easly see 8400 rpm and the 90 can quite easly see 7800. In either case, more power than you will fight to get with the omc. ( That statement will start a fire for sure) Just some thoughts for you to kick around, don't limit your self on motor options.

[ima75man]

u right, u starting a fire.lol my 60 h/p omc is faster than my 90 yamaha.. just ask donnie or the bama boyz..

[phillnjack]

was that a joke about the yamaha 70 and 90 engines ?




phill

[Hounddog]

Here you go. Just a stock 56 motor no mods other and using a 28.5 CC SST 60 head. Powerhead cost including the head $700.00 to $800.00.
http://www.youtube.com/watch?v=NaYLot_1XBY&feature=plcp

[Powerabout]

maybe the orange things with 75 stinger on them over here in uk were all just crap and sold as a gimmic.
coz they sure were not fast compared to most others around.

now the sst 60 i have no idea about, never seen one in the flesh.
I take it these are proper engines similar to motorcycles that push out over double what outboards do for
the same cubic capacity.


phill
The 75 would be the last engine I put on a ski boat due to the tall gear ratio and small prop.

There is a reason that bikes can make more horsepower than a boat engine for a few very simple reasons
they have gears
therefore can make use of long expansion chamber
are not required to produce full power at full load sustained
therefore can have power valves on the exhaust which will not last at sustained full load

( just ask a BRP 2 stroke engineer as they make engines for all uses)
PS 3 cylinder Mercs were never in the race as a racing compeditor to the OMC 3 cylinder and I guess 20 years of results proves that
The OMC 3 cyl was the only OMC that my mates at Mercury would concede was a good engine - because they couldnt beat it clearly

[Powerabout]

Hounddog
can you run 160 psi with pump gas in Canada?

[phillnjack]

what is with the talk of 160psi

is this what yourgetting on a compression test or what ?
in the uk when talking about cylinder heads we talk of different measures .

yes we do say things like high compression , but then it goes to the ratio.
so 160 to me sounds like your compression test.

such a big difference in the way things are described between usa and england.

and whats with the canada pump cause talk ? is that very high octane or low octane ?
in uk our average is about 90 octane.

phill

[Powerabout]

what is with the talk of 160psi

is this what yourgetting on a compression test or what ?
in the uk when talking about cylinder heads we talk of different measures . ( No you dont)

yes we do say things like high compression , but then it goes to the ratio.
so 160 to me sounds like your compression test.

such a big difference in the way things are described between usa and england.

and whats with the canada pump cause talk ? is that very high octane or low octane ?
in uk our average is about 90 octane. ( you need to know if you are talking RON or MON, Tesco Momentum99 is 99 RON 87 MON)

phill
phininjac
I'm from OZ so I know both systems,
compression ratio on a 2 stroke doesnt work like a 4 stroke as a 4 stroke is measured as a percentage of total cylinder volume ( useless when you have ports in the cylinder), hence the industry uses cranking pressure and even sometimes measures the cranking rpm to create a specification ( like with the ignition systems)

Pump gas
The numbers are different in different parts of the world as some use RON and some use MON ratings and they do not directly convert, I think Canada same as US, UK same as OZ
AV gas has international standards for obvious reasons and both are now called 100, 100LL ( has more lead than automotive ever had)its blue and plain old 100 its green has 3 times more lead (MON ratings)

PS ther are a few language barriers
torch = gas axe not flashlight
Beer = ??
box wrench = ring spanner

[Hounddog]

Hounddog
can you run 160 psi with pump gas in Canada?
We kept the rule very simple. Yes, we are talking 160 lbs on the compression gauge. The head we use is the spec head for the SST60 motor. On the SST60 motor that head produces 180 lbs compression. We tested different heads on different motors to find one that improved the performance and was easy for a racer to get. The motors have no problem running on premium pump gas. This is the head we use for the bridge port fishing motor. That motor had the 4 spline crank from 1986 until 1988 and it is the same spline as the 49, so racers do not have to change the crank. The later 56 fishing motor is an oval port motor and it requires different head.

[phillnjack]

so you are using a head with a smaller squish clearance then to give higher compression.
whats is or would be the problem of shaving off a couple of thou on the later 56ci to bring the compressin up higher ?

I would think anyone with a slight bit of damage to a head would have it skimmed to re-use anyway.

I get 145 compression with dry cold testing on a 56ci bog standard motor, if i was to skim the head by a few though
then this would probably be taking me to 160+ psi.
or is it that the later heads cannot take any skimming due to small squish clearance ???.

well what about doing a few improvments to the head on the later engines ????
or is something not right about them for modding ?

phill....

[Hounddog]

One last try.
Here is the SST60 spec sheet
http://www.apba.org/sites/all/files/documents/60.pdf.
The head is a cut head that measures 28.5 CC. Same stock fishing head shaved down to that spec.
That head on a 86 to 88 bridge port, non decompression, fishing motor gets you 160 lbs compression.
It will be different of any other block.
Since you have 145 compression then I am guessing yours is a later model oval port motor. For that than motor we take less off the head to arrive at the 160.

[tumblweed9999]

FYI for you guys ....I think I see the sought after "lighter 72 flywheel" on ebay today. Its sitting on a complete 49 cid powerhead in Florida. advertised as 1973 Johnson. I have both flywheels and I'm pretty darn sure thats the one. has the skinny teeth. http://www.ebay.com/itm/1973-Johnson-Evinrude-65-HP-Outboard-Motor-Complete-Power-Head-/110988511558?pt=Boat_Parts_Accessories_Gear&hash=item19d76e4946&vxp=mtr ... seller is leeannmcil can anyone confirm that?

[phillnjack]

"Since you have 145 compression then I am guessing yours is a later model oval port motor. For that than motor we take less off the head to arrive at the 160. "

How much is shaved off the head of the later oval port ? and what would be the limit that can be taken off ???

phill

[Hounddog]

We have only surfaced the block and the head on that model. We think? That is all it needs to be competitive in our T class.

[phillnjack]

But if one wanted to go to the extrem what can be done with the later 56ci.

is there any mods that can take this engine a lot further ? or would it then become unreliable.

would the 56ci later 70hp be a lot more powerfull than say a sst60 if these mods were done to it ?

i ask as in the uk, it seems that the later 56ci engine is the one thats being used for racing and it
is breaking some of the records.



phill

[phillnjack]

Also i have a head that will need skimming pretty bad, and need to know just how much can come off it to be safe.
its for a spare engine that im hoping to rebuild of the winter/spring.
if there is many mods to be done it might be a time to do it as it will need a re-bore
new pistons rods etc.
i think its possible to re-bore it, if not might be able to get it sleeved.
Im hoping the crank is ok and will get it checked out, the engine was run dry of oil by previous owner and
middle piston and bore suffered bad scores .
no 1 and no3 are not too bad,

maybe this could be a slighter more powerfull engine when re-built.?



phill

[phillnjack]

I will start a new topic on the re-build of a late 56ci and see what i can learn about that.

i am learning lots from this forum already.
its another great forum about boats and engines.




phill

[88workcar]

was that a joke about the yamaha 70 and 90 engines ?




phill

No Phil, not from me. My jokeing days are long gone. You ever make it down here bring your own gps, I'll launch the boat and give you the key.

[phillnjack]

A yamaha 70 will not touch a johnson 70 unless the yamaha is very modded.
Ive seen plenty of yamaha engines trying to keep with the johnson and evinrudes, they just
dont have it in them.
A good 60hp triple mercury 2 stroke will stay with the yamaha 70 no problem,been there and done it a good few times with same boat.
2 friends of mine both had the dellquay dory 15 footers1 with a yamaha 70 1 with a evinrude 70 and my dell quay 15 with a mercury 60.
i could stay with the yamaha ,but had no chance at all against the evinrude, he was gone and his top end was about 10mph morethan us.
maybe your 70 is realy a 90 ??????????


phill

[ima75man]

maybe you should send your mercury to hydrotec,and let them speed it up. 88workcar runs against the fastest boats in la. and texas and don't have to back up to anyone..it's what it is..

[phillnjack]

I never said the mercury 60 was slow !!!!!!!!!!!
for 60 i think it was very good for its size, and ultra reliable.

i said the mercury 60 is as fast as the yamaha 70..
i was saying the the omc 70 is the fastest of all 3.

Ive had all three engines, i know what i know due to running them myself.

The yamaha has the weakest gearcase bullet for sure,always seeing them welded up by the front ring.
evinrude i would say is far stronger and more power.
Mercury is the most reliable of the 3 engines for sure.