E-Tec sinks Yamaha
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E-Tec sinks Yamaha
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- Brewster Minton
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Everyone who ever ran a 2 stroke dirt bike knows they will out torque a 4 stroke.
2 strokes have the advantage off the line where that contest was played out.
Certainly NOT an equal test.
Hell the media made Obama look good to the majority, looks like that contest wasn't so honest either now was it?
2 strokes have the advantage off the line where that contest was played out.
Certainly NOT an equal test.
Hell the media made Obama look good to the majority, looks like that contest wasn't so honest either now was it?
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etec
had a 348 Intrepid a few years back and finally figuered out why I had 2motors, always seemed to limp off the ocean on 1 engine, tough to resell, never refused a warranty issue, never buy again. Got smart and bought a 28 buddy davis with 250 merc verados and again limping off the ocean or getting towed in because of computer problems. I had the boat on the greatlakes this past summer and couldn't find any dealer that could spell verados, this is the main reason I went with cummins cause nobody heard of yanmar in the midwest
marlin your one classy guy with a intrepid 348 and then a buddy davis!!!! don`t fret the verados all of the big four strokes sooner or later have computor problems.we can`t even have the better yardman winterized them. a little fogging oil hits the o/2 sensor and the computor goes out of wack.very sensitive piece of equipment.NOT MY OPINION when the big four strokes go out of warrantee we can`t even give them away.at $26,000 a copy times two or three you get four year to enjoy then bailout!!! extended warratee is big bucks!!
capt.bob lico
bero13010473
bero13010473
Huh? Did I hear dirt bikes?So Bruce, it used to be the two stroke had about double the power the four did per same C.C. And they did. If you snapped the throttle on a CR250R you would be launched forward or, if not hanging on, would be hovering in the air while the bike shoots forward under you fifty feet. An XR250R would have a more linear power delivery with overall less power as well, taking some time and rpm to make it's power. Now however, the CR250R could not keep up with a CRF250R (4stroke) on the track. All due to higher compression, ign. curves, decreased piston skirts, and overall technological advances.
The two stroke still has more "snap" of the throttle though, and that's why this test above was doomed from the start, as the two stroke had the Yamaha beat from the start, making instant gobs of power at the crack of the throttle. God that makes me want to ride!
The two stroke still has more "snap" of the throttle though, and that's why this test above was doomed from the start, as the two stroke had the Yamaha beat from the start, making instant gobs of power at the crack of the throttle. God that makes me want to ride!
Bruce-
Once again you hit the nail on the head. It comes down to the equation for horsepower (both are equal HP? correct). Torque and RPM are in the equation. I suspect the Yamaha makes its power out at max RPM.... while the Evinrude most likely generates lots of torque as the 2 stroke hits hard early, and never lets the yamaha get up to its max rpm...so doomed from the start. Having raced both 2 stroke and 4 stroke dirt bikes for many years, the solution on the liniear power delivery of the fourstroke was always to fan the clutch to get the revs up quickly...and then unload(of course only works when you have traction). That said in that domain, sometimes making power slowly was an advantage in terms of traction. All the guys I rode with all switched to fourstokes at once, and we called the clutch our second throttle....Most of us switched back, and as for myself, back and forth a couple of times, so I have a good perspectic eon the contrast between the two motors (2 stroke vs 4 stroke). Obviously with the boat, fanning the clutch is not an option. I wonder how the test would go if you had a varuable pitch prop that would allow the fourstroke to rev out a little, then gradually increase the pitch.
Not knocking the Evinrude....but historically, Yamaha has made some very sweet engines, so I would'nt consider them toilets. The new YZ dirt bikes are a great example....and my 1995 Tourus SHO was another example of fine engineering.
Yo Rocky,,,I'm thining the same thing,,,been a while, but i recently got a taste (see I'm done post)....nothing beats ringing a dirtbike out!
Once again you hit the nail on the head. It comes down to the equation for horsepower (both are equal HP? correct). Torque and RPM are in the equation. I suspect the Yamaha makes its power out at max RPM.... while the Evinrude most likely generates lots of torque as the 2 stroke hits hard early, and never lets the yamaha get up to its max rpm...so doomed from the start. Having raced both 2 stroke and 4 stroke dirt bikes for many years, the solution on the liniear power delivery of the fourstroke was always to fan the clutch to get the revs up quickly...and then unload(of course only works when you have traction). That said in that domain, sometimes making power slowly was an advantage in terms of traction. All the guys I rode with all switched to fourstokes at once, and we called the clutch our second throttle....Most of us switched back, and as for myself, back and forth a couple of times, so I have a good perspectic eon the contrast between the two motors (2 stroke vs 4 stroke). Obviously with the boat, fanning the clutch is not an option. I wonder how the test would go if you had a varuable pitch prop that would allow the fourstroke to rev out a little, then gradually increase the pitch.
Not knocking the Evinrude....but historically, Yamaha has made some very sweet engines, so I would'nt consider them toilets. The new YZ dirt bikes are a great example....and my 1995 Tourus SHO was another example of fine engineering.
Yo Rocky,,,I'm thining the same thing,,,been a while, but i recently got a taste (see I'm done post)....nothing beats ringing a dirtbike out!
Giff
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The difference between two strokes and four strokes are really very simple; at any given RPM the two stoke has fired twice as many times, burning twice as much fuel.
More fuel, more power.
In practice, one isn't twice as good as the other. Two strokes are by their nature less thermodynamically efficient, for which some manufacturers compensate partially by employing fuel injection. Also, most manufacturers take advantage of the higher specific output to produce a given level of horsepower out of a smaller, lighter powerhead. So you are rarely comparing equal displacement and rpm between motors.
I suspect that even in the dirt bike world where displacement is the governing criteria, if Honda was able to employ direct fuel injection on the 250 two stroke it might have been a different outcome.
Personally, I prefer four strokes. I don't like throwing fuel away...
Cheers!
John
More fuel, more power.
In practice, one isn't twice as good as the other. Two strokes are by their nature less thermodynamically efficient, for which some manufacturers compensate partially by employing fuel injection. Also, most manufacturers take advantage of the higher specific output to produce a given level of horsepower out of a smaller, lighter powerhead. So you are rarely comparing equal displacement and rpm between motors.
I suspect that even in the dirt bike world where displacement is the governing criteria, if Honda was able to employ direct fuel injection on the 250 two stroke it might have been a different outcome.
Personally, I prefer four strokes. I don't like throwing fuel away...
Cheers!
John
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hitting a rock is covered under insurance, you cant go about your life worrying about things like that otherwise you would scare yourself out of leaving the house.aeymardz71 wrote:walter
hitting a rock is not under the warranty, it was just an example of the cost of parts, when a yamaha lower unit costs $2,900 for a 225hp.
Another nice feature of the ETEC- the self winterization feature, that is nice.
They are not too popular in this area, but the people I do come across who have them love them, the 250 we put on a whaler he is not easy on that boat at all and he loves it.
I have also never heard any engine, car or boat, that fires and starts up as quickly as those ETECs, its unreal.
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