Yamaha 2 strokes

[sparkyaber]

What is the difference, if any, between the vmax, and the solid grey cowled hpdi motors from yamaha? I didn't know that there were two different motors. I looked at the current models, and only the vmax is offered. Anyone have any experience with them (more interested in the one with the grey cowling)? Good or Bad? How are they on fuel economy? Reliablility?

[mamohr686]

You'll need to find out if it a OX66, or carburated model. Because of new epa laws new manufactured outboards can only be 2 stroke directed injected or 4-stoke models, that's why you only have one V-MAX choice now. Before that Yamaha made a carburated version, and OX66 which was an electronic fuel injected model, and lastly the HPDI which is a direct injected 2 stroke outboard. All 3 motors have the V-Max logo. The cowl color doesn't tell me a whole lot. At one point Yamaha came out with an outboard call TRP about 97' or 98' which had twin rotating propellers, and they had a grey cowl when the others didn't (the purpose was to differentiate the between the regular and twin prop model). Later when the OX66 came out, they had a grey cowl the first year of production to differentiate between the carb and EFI model. I had a V-max 150hp Carburated outboard and it was super strong, I never had a problem but some guys I knew had to replace some fuel pumps because they ran cheap ethanol gass that ate up the plastic diphrams in the fuel assembly. Basically depending on the year, the grey color indicated a new model or design.

[sparkyaber]

Sorry, I typed the first post early in the morning, I didn't add that it was a 2005 HPDI that I was looking at, with a grey cowl, like the four strokes. No metion of a Vmax any where. I was thinking about this today asking a few coworkers, and it dawned on me, I thought they made them with two different shaft lenghts, a 20", and a 25"......

Could this be the difference, a Vmax for the bass boats with a 20" shaft, and a grey, 25", less flashy for the walleye boats?

[trackerbrent]

You are right. The grey cowling hpdi's are 25" and 30" shafts. I still do not know if I trust this new technology. My buddy just bought a brand new Ranger Z20 with a 225 Vmax and has went through a fuel pump and computer. He has only had it 2 months. I think I will stick with my carburated Johnson 150. It may not run as smooth, start as good as these new motors, but it will always run without all the fancy electronics getting in the way.

[Down Deep]

I had a 1999 150 Vmax o66 and it was rocks solid. It had a powerful hole shot and topped out at 48 -50 wot pushing a Lund ProV 1800. The only problem I had in 8 seasons was a fuel pump gasket started leaking. My fishing buddy still runs a 200 150 HPDI and he has had zero problems. Yamaha motors are top shelf. Both motors suck lots of fuel, but the HPDI is maybe 20% - 25% better.