90 hp yamaha question

[PIP]

I am sure there is something i am missing here. I hear a lot of guys are into the 90 yamaha 3-cylinder motors, but unless i am wrong, I don't get it, because doesn't it weigh almost as much as a 140 crossflow (115 or so at the prop) and doesn't the crossflow have a lot more torque also?

it reminds me of when people talk about how great the E-Tecs are and how "fast" they are, but the thing is, for the weight that they are, an old v-6 crossflow at 150 horsepower (or more) doesn't weigh much more than a 90 horse E-Tec. it seems that maybe the excitement over the E-Tec is because it is better than the 4-cycle alternatives, and per cubic inch, it burns efficiently, but, pound per pound, i just don't see them as great.

somebody school me up if you would. what am i missing?

thanks

ronny

p.s. this is not meant to offend any lover of the 90 yamaha or e-tec. i just want to understand what the attraction is.

[FrenchPhil]

The 90 (&70hp) Yammies are very popular in Europe. They hold alot of inshore & offshore UIM records. The smaller american 3cyl race motors were hard to find so the 3cyl Yammies were the thing along with the use of moded l/u's :
Look at 3B offshore & S850 inshore :
http://www.uimpowerboating.com/vsite/vnavsite/page/directory/0,10853,4916-151354-168570-nav-list,00.html

[50hptiller]

the 90 yam that i have is on a mariner w48 15" inch mid with a 60 mariner gearcase. it puts out well over 100 hp and does not weigh that much. i would guess maybe 240lbs. because the original 2cyl only weighed 170lbs or so. same bore and stroke just 1 more cylinder

[YAMAHAFASTCRAFT]

i have a 90 yamaha and it weighs about 200lbs.it is just like the one above and have no clue how much hp.but no it is over 100

[Roflhat]

Anyone got photos of these 90 shorts? I'd like one!

[Fast Fred]

crossflow motors are for low speed, trolling . they are not cut out to do it like a Looper.

[Roflhat]

What would you recommend for an SLT? Need it to be lightweight for jumping waves

[champ20B]

I am sure there is something i am missing here. I hear a lot of guys are into the 90 yamaha 3-cylinder motors, but unless i am wrong, I don't get it, because doesn't it weigh almost as much as a 140 crossflow (115 or so at the prop) and doesn't the crossflow have a lot more torque also?

it reminds me of when people talk about how great the E-Tecs are and how "fast" they are, but the thing is, for the weight that they are, an old v-6 crossflow at 150 horsepower (or more) doesn't weigh much more than a 90 horse E-Tec. it seems that maybe the excitement over the E-Tec is because it is better than the 4-cycle alternatives, and per cubic inch, it burns efficiently, but, pound per pound, i just don't see them as great.

somebody school me up if you would. what am i missing?

thanks

ronny

p.s. this is not meant to offend any lover of the 90 yamaha or e-tec. i just want to understand what the attraction is.

PIP, a lot of times manufacturers use the same engine platform to offer several HP versions to save in production cost. For example, Mercury used to make those inline six models that ranged from 100 to 150+ hp. They were all the same displacement/engine block and weight, they were virtually identical. They were just souped up internally with different carberators. That is why a 90hp might be close to a 140 in weight, because they are really quite similar in overall size and probably also displacement. This can be true comparing different brands in the same respect. In some cases this may not be so, as well.

As far as the E-Tec, it is the current must-have outboard. It is proven to be of the higher quality so far. Amongst other interesting features, you would be garuanteed not to have to change the gear oil the first three years. It is also likely underated in power, meaning that it is actually equivalent to many other brands of higher power. This practice is not unusual in outboard production with hot new style models. I have actually seen these things run and have talked to owners at the boat ramp. They always say that the performance is greater than their previous engines of equal and even greater power rating. They never said that there was any trouble with these engines and seem to be quite happy with their choice. If I ever buy a new outboard in the future, this would be it.

[Fast Fred]

50hp with carbs best wave jumper, yamaha or nissan. E-tec's got the EPA on them and they are 10 pounds of crap in a one pound bag. they are nice for what they are but you don't really own it for it's against the law to make any mods at all, and the way they are built mods are hard to do, there is a paper trail as soon as it's started. you need a computer to start it out of the box.

[Roflhat]

Cool. I've already got a tohatsu 50 modified. I know a few guys with E-tecs and they're had nothing but problems with them. Fred would you mind having a look at my thread? - http://www.boatracingfacts.com/forums/showthread.php?16744-My-Thundercat
looking for advice to make my engine run properly
Cheers

[Fast Fred]

Etec's are what they are, and if you need a warranty they would be the ones, the only time i've seen them have trouble is when people try to run them on water, still haven't seen any gas moda run on water no matter who it's from. so Roflhat how is she runnin?

[Roflhat]

She's running smooth enough, just not revving how I'd like her to. I get around 6300rpm with an 18p chopper at 51.7 knots. I'm looking for another 5 knots with this prop really, at over 7k rpm.
Not sure where to set the timing at? Would the timing stop it revving higher?

[FrenchPhil]

Then you'd be close to Rowan's P750 UIM record. That would be quite a feat.

[Roflhat]

Yeh. I reckon that's doable, in one direction at least. The record is an average over both directions. There's a few guys on the thundercat forum who are getting around 60 knots with 50hp engines