VMax Carb, VMax HPDI and 4-stroke F series ?'s

[eyepatrol]

Being I don't know much about the Yamaha line of motors, I was wondering if someone could explain to me the differences of the above brand motors and also how these motors would rank against each other in price.

Thank you!

[Wave Runner]

The HPDI stands for high pressure direct injection, the carbed model is the "old school" in technology and the F Series are the four stroke models. The V-Max HPDI is an HPDI with a more streamlined lower unit, usually only comes in 20" and was originally designed for bass boats.

I've owned two HPDI's (a 2002 150 V-Max HPDI and a 2004 200 HPDI) These two are the best two outboards I've ever owned and I've owned a bunch. I had the 2002 V-Max HPDI on a 2002 Lund Pro-V that still had a 20" inch transom and that was a sweet running rig. Great hole shot and good top end.

I owned the 2004 200 HPDI on a Pro-V also and the 200 HPDI is one of the most reliable products Yamaha has ever made. A little less aggressive than a V-Max HPDI but still impressive in terms of performance.

With either HPDI, starting is instant. Even right after winter storage, they just start right now.

The HPDI's and the four strokes are virtually identical in terms of fuel economy with a modest edge in performance to the HPDI series. Either of these stand well above the carbed models which are being discontinued soon if not already.

Pricing difference between HPDI and Four Stroke is not much. Good deals are available on both if you time your purchase right. Both of these are proven products with excellent reputations. The carbed model was also in it's day but that's in the past now.

[iffwalleyes]

Bass a hpdi would be very similar to the Optimax that you have had and are familiar with. Then a 4 stroke is a 4 stroke of course quit and clean. The HPDI are also very quite and clean too. Kind of the ford vs. chevy deal 4 stroke or HPDI. Performance wise HPDI will probably have more top end etc. The the 4 strokes on the market are pretty darn good too in the performance end of things.

[CASTnBLAST]

There was recently a shootout of the 250hp motors available in Bass and Walleye Boat magazine and it may be on their HSOforum also.All were 4 strokes except one and it was quite interesting how the comparisons blew holes in all the theories about fuel consumption/emissions/noise levels etc. of the 4 strokers. Check it out if you get the chance it's a good read.

[Valv]

Hey, don't you wish they made a TDI (Turbo Diesel Injection)

It would have so much torque......

[eyepatrol]

Thanks for the helpful info all. I had an incling that those were the differences, but wanted to be certain.

Speaking of motors, I received an E-tec dvd a week or so ago where they compared their motor to the Yamaha 4-stroke and the Verado. Some interesting differences, but the one thing I found most interesting was the race they had between 3 Triton bass boats all rigged with 225's. In 2 miles the E-tec outran the Yammi and Verado by 4 seconds (not much really), but what I really found interesting is the Yammi and Verado crossed the finish at basically the exact same time. Seems to me those Verados aren't as supercharged as they lead one to believe. A little unfair to be comparing 2-stroke DI's to 4-strokes IMO, but it was an interesting video.

[marine_man]

Regarding the DVD you received... remember that the DVD is made by Evinrude... so the results very well could be biased a little... Bass and Walleye Boats is a good, objective magazine that typically has pretty good reviews and gives you all the numbers from their tests.

marine_man

[eyepatrol]

I agree. I thought the video was a bit biased and to some degree unfair trying to compare 2-stroke vs. 4's, but then again they don't make a 4-stroke so they're trying to sway opinions I think.

I went on that HSOforum last night and read all kinds of good info on the various comparisons, tests, etc. Very informative!

[PerchJerker]

The supercharger in the Verado was to give it more punch out of the hole than a typical 4-stroke, which I think it does. It costs you some fuel economy at WOT though compared to other 4 strokes and DFI motors.

4-strokes are quieter than DFI motors, but at high rpms there is not that much difference in noise.

You know which way I went with my motor, the yamaha HPDI was my 2nd choice. If I wanted a 150 HP the F150 would have been my second choice, maybe even my first choice.

Stay away from the carbed versions.

[iffwalleyes]

Quote:

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Thanks for the helpful info all. I had an incling that those were the differences, but wanted to be certain.

Speaking of motors, I received an E-tec dvd a week or so ago where they compared their motor to the Yamaha 4-stroke and the Verado. Some interesting differences, but the one thing I found most interesting was the race they had between 3 Triton bass boats all rigged with 225's. In 2 miles the E-tec outran the Yammi and Verado by 4 seconds (not much really), but what I really found interesting is the Yammi and Verado crossed the finish at basically the exact same time. Seems to me those Verados aren't as supercharged as they lead one to believe. A little unfair to be comparing 2-stroke DI's to 4-strokes IMO, but it was an interesting video.

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God I hope they didn't show the guy in his pink thong in the Video .

[Rockin Rod]

Ok, I have another question related to this: I have a 2000 v-max 150 that is EFI, but not HPDI. What is the difference between these?

[PerchJerker]

EFI is fuel injected, it is not the same has HPDI which is direct injection. I can not explain in detail the differences between the two but it has to do with how the gas, air, and exhaust are treated and burned inside the engine. HPDI is the newer technology, much more fuel efficient, much lower pollution.

[Wave Runner]

They're both fuel injected but the HPDI stands for high pressure direct injection. Depending on the model year, the fuel is pumped into the cylinders at between 700 and 1,000 PSI by a fuel pump that runs off the flywheel.

The HPDI starts instantly compared to the EFI's habits (cold blooded sometimes) and the fuel economy of the HPDI is much better than an EFI.

[ricqik]

In EFI, fuel is usually injected to the cylinder thru the intake ports. In a HPDI, the fuel is injected directly into the cylinder.