New Yamaha 4 strokes

Wonder if they are light enough to hang on a 282 Sailfish? I think it's rated for 600 H.P. :?
 
I would say absolutely. The new 300 weighs almost the same as the old F250s. That Sailfish might hit 60 with 600 HP pushing it. :lol:
 
Suzie's 300 HP 4 stroke finally has competition.

It's about time.
 
And I forgot,

Yamaha finally has a proper 300 HP 4 stroke to sell - replacing the 300 HPDI.

It will also allow higher power - repowering over the F250s. I see this motor outselling the F250s, in both singles and twins.
 
If I had $40K burning a hole in my pocket a pair of 225's might be hanging on my bracket. These 225's should put out 225 HP not under 210 and the digital control would be schweeeet for trolling.

I'm suprised that they even put out a 300 with the V8, the power/weight ratio stunk.
 
I would guess the 300 with rigging would run about $22k installed. I have read that they will not be available for the repower market until March of 2010 or thereabouts. I gather the boat manufacturers get the first batch, then the dealers get their engines second to sell as a repower.
 
All Yamaha needs to offer next is a properly weighed 200Hp 4 stroke, then follow-up with 25 more ponnies from the F150.
 
here is the thing we all need to keep in mind, I have a 330 express with twin 300 hpdi, i went to Grady last year and asked if I can put the new 300 v8 4 strokes on and they said no way. The torque would rip your transom off, the new boats have a reinforced transom. Do these v6 four strokes have to much torque for the older transoms?
 
nevercontent said:
here is the thing we all need to keep in mind, I have a 330 express with twin 300 hpdi, i went to Grady last year and asked if I can put the new 300 v8 4 strokes on and they said no way. The torque would rip your transom off, the new boats have a reinforced transom. Do these v6 four strokes have to much torque for the older transoms?
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Good point there...I was really hoping for a new 4 stroke for spring.... I don't recall the model number but they are ressurecting an old 250 for repower purposes for older boats....
 
nevercontent said:
here is the thing we all need to keep in mind, I have a 330 express with twin 300 hpdi, i went to Grady last year and asked if I can put the new 300 v8 4 strokes on and they said no way. The torque would rip your transom off, the new boats have a reinforced transom. Do these v6 four strokes have to much torque for the older transoms?
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I had ask the same question to them(Grady) for my '07 330 and told me that it was a weight issue, they did not mention torque.
 
Granted, I'm no ones mechanic, but...
If a 2-stroke has more low-end planing power, how can re-powering with 4-strokes of the same HP "rip the transom off?"

I can see reinforcing the new transoms to accommadate the weight of the 4's but I can't believe they would have that significant a difference in torque.
 
I doubt the F300 has more torque than the 300 HPDI, not even the F350.

If the motor manufactueres published the torque & HP v.s RPM curves like we see in car magazines, there would have that much less BS in our lives to wade thru.

The behemeth F300/F350 is over 800 lbs.
 
Lighter weight, better fuel economy and performance all add up to the end for two stroke outboards. I've been waiting for Yamaha to come out with their second generation four strokes and these truly do look like a game changer.
 
magicalbill said:
Granted, I'm no ones mechanic, but...
If a 2-stroke has more low-end planing power, how can re-powering with 4-strokes of the same HP "rip the transom off?"

I can see reinforcing the new transoms to accommadate the weight of the 4's but I can't believe they would have that significant a difference in torque.
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I have to waive the BS flag on that one. The two probably have a very similar torque curve even though one is a 5.7L and the other is a 3.3L. The weight issue is where the problem may be. The old F300 weighs about 300 pounds more than the HPDI and I'm not sure how happy the transom would be with over 600 pounds more weight hanging off it.
 
The F300/350 are pathetic motors if you look at their weight vs. HP rating. This leads one to believe that Yamaha restricted the HP from it's ultimate capability when they marketed these behemoths. It's easy to do by just limiting max air flow in the throttle bore to a smaller bore.

It's been reported (by Yamaha reps at the boat shows) the motors are good for as much as 400/450 HP (I don't recall which), which makes sense at over 800 lbs.

Grady may have changed the stern design to cover 400 to 450HP on twins on single, to avoid making a second design change down the road.

I'm sure plenty of original owners and potential used market owners are very dissapointed the 330 can't take these motors, and no Yamaha bigger than an F250 on twins is available.
The 330 and it's CC counterpart would be ripping hot with F350s, F440, or even F450s. Too bad.
 
the F350's were not designed as hot rod engines but main application was aimed at larger and heavier boats that would benefiit from the power and longevity too. A HO 350HP engine is fine for a go fast boat, but those wanting a higher degree of dependability and durability the F350's make a nice fit. Is the f350 heavier than any other 350HP OB? yes, but i'd put money on it that it would last longer and with fewer issues. After another year or so i can see the engineers letting the v8 design pushed to 400+ HP after proving itself. The F350's have also allowed many trip applications to run twins and allowed larger boats traditionally powered by inboards or sterndrives to have outboard power.
 
the SHO motor puts out over 400hp now, nut they will not let it go out yet, not 3 star

also hydro-tech is going to start to work on them

i can see 550 on the 350 v8 motor
 
sent a quick email to gw. looks like the new v-6 4 strokes will be ok for re-power of older hulls rated for similar hp - due to low weight. anybody doing so should probably validate their specific hull/year with gw to make sure. ron
 
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