whats difference in vmax hpdi an vmax series 2

[dflick22]

i see some of the Yamaha are v max series 2....whats this mean?? whats the difference....??

[Rich Z]

Main difference is that the series II have forged pistons. Much stronger than cast aluminum pistons.

[Reata210]

There is no difference in the pistons. Yamaha stated in marketing materials they use Forged pistons in the Series2 but what they did not tell you is that they have always used Forged pistons in everything. It sounds good though. They are the same part number in all 3.3’s. They also mentioned the addition of another ring totaling three. There are two rings just like all big block HPDI’s prior to Series2. Another marketing blooper.

The only difference is the sticker on the cowl from anything MFG Jan 07 and later. The last run of HPDI non branded Series2 had all the changes and are identical. This would include the ECU changes, fuel mapping and updated oil pump. Series2 is more marketing to get away from the oil pump calibration failures and subsequent recall/replacements.



Modified by Reata210 at 10:55 AM 5/31/2011

[Rich Z]

Piston part numbers are different and I have never seen an oem forged piston in any older 2 stroke.

[Reata210]

Actually Rich, I have a MFG Jan 07 225 Non Series2. The Series2 came out 6 mos later and piston part numbers are the same on my engine as the S2 verified with HT. Also spoke with Yamaha when I was checking to make sure I had all Oil Pump updates and was told the last run of Non S2 HPDI had all the small changes that were made to the S2. I also verified with HT that Yamaha has always used “Forged” pistons in all of their HPDI and HP OB’s. S2 is all about marketing.

[hawkeye]

My boat and engine are exactly the same as your. I have a vmax hpdi manufactured in Feb 2007 and a 2008 Ranger Reata 210VS. Did you get a casting deck extension from Ranger?

[Reata210]

Yes, I got the casting deck. Overall it has been a great boat.

[Rich Z]

Oh yeah, HT...you get a story one day and a different one the next.
And I dont know of any HP OBs that Yamaha manufactures.

[Reata210]

<table width="90%" cellspacing=0 cellpadding=0 align=center><tr><td>Quote, originally posted by Rich Z &raquo;</td></tr><tr><td class="quote">Oh yeah, HT...you get a story one day and a different one the next.
And I dont know of any HP OBs that Yamaha manufactures.


</td></tr></table>

Instead of providing supposition how about looking up part numbers like I did. My dealer was happy to compare the part number for me. Regardless of what YOU think about HydroTech the part numbers do not lie and they use the very same pistons in a S1 as they would use in a S2 per Yamaha and most seem to be happy with their work. Bottom line: There is no change from series from Series1 to Series2 pistons.

As far as Forged pistons go, Yamaha has always used them on HP OB’s (As far as I understand, the HPDI is considered a HP OB…Translation: High Performance Outboard.) Like anything some may in fact debate those merits. The OPTI and ProXS from Mercury also use Forged vs. Cast pistons. This is not a new phenomenon. The only new phenomena is that Yamaha elected to use the word Forged in their market of the S2. It was very smart on their part and seemed to work very well by listening to you.

[Rich Z]

I stand corrected. Recently Yamaha updated their part numbers. However, the S1 piston and part numbers were different from S2. Now, as a replacement piston for S1 you get the same piston as S2. Anyone who is still running a S1 build before 06 does not have the same piston unless the power head was recently rebuild. Unfortunately many have experienced piston failures in my opinion because of planned obsolescence. You can view the updated and old part numbers on Yamaha website.

I don’t know what makes you think that the HPDI is high performance motor. Would you consider a VX or F models as such? My understanding of high performance would be any motor that is build to perform beyond the normal operation of manufacture or EPA standards. The F-1, 300 drag, 280 and 260 are the only high performance motor still manufactured and I think only replacement drop-on power heads are made.
I apologize about HT comment. That was uncalled for. I know many who think very highly of them, just not me.

[Reata210]

I never looked any part numbers for MFG 06 or earlier just the Jan 07 S1 vs all S2 and like verified all part numbers are the same.

Regarding, what makes a HP engine; In their line up the Vmax HPDI or SHO like the ProXS for Merc is marketed as a HP OB. I agree once something is modified to produce more HP and performance gains, then by definition that is considered HP. I do believe you can have something bone stock and still be a HP offering, look at the Auto MFG’s, there are many examples of HP vehicles that are bone stock.