Info please on 150hp VMax

[Soan]

Looking at buying a boat with a 2006 VMax 150 hp on it. I know nothing about Yamaha engines other than they are supposed to be good. I have found out that I can't get a read out on this engine so that only leaves me the option of a compression test. May I get some info that I should look for about the engine and what the compression should be. Thanks for any info I might receive.

[jethro1]

There are several different versions of a VMax 150. I suspect that the one you are considering has carburetors. With that model you are correct, there is no engine readout data available to a PC running Yamaha software.

That model is one that Yamaha made their reputation on. Has carburetors and an electric choke that can be fussy but that is pretty much it. Keep the fuel clean and fresh and you should have little to no problems.

A visual inspection, view of the maintenance records and a good compression check are some things that you can do to try and determine the condition of the motor. Does it look well cared for, does it start easily when cold and hot, does it idle well, and run well at full power? Drain the lower unit to verify the oil looks good and no water is present.

I would suspect that the compression will be in the 120 psi areae. All cylinders should be within 15% of low to high. Many factors determine what will be seen on a pressure gauge. Gauge should be known good, motor hot after having been recently run, throttle wide open, battery fully charged, with the motor being cranked until the pressure stops rising on the gauge.

[allen656]

There are several different versions of a VMax 150. I suspect that the one you are considering has carburetors. With that model you are correct, there is no engine readout data available to a PC running Yamaha software.

That model is one that Yamaha made their reputation on. Has carburetors and an electric choke that can be fussy but that is pretty much it. Keep the fuel clean and fresh and you should have little to no problems.



A visual inspection, view of the maintenance records and a good compression check are some things that you can do to try and determine the condition of the motor. Does it look well cared for, does it start easily when cold and hot, does it idle well, and run well at full power? Drain the lower unit to verify the oil looks good and no water is present.

I would suspect that the compression will be in the 120 psi areae. All cylinders should be within 15% of low to high. Many factors determine what will be seen on a pressure gauge. Gauge should be known good, motor hot after having been recently run, throttle wide open, battery fully charged, with the motor being cranked until the pressure stops rising on the gauge.

all of the above! they use the term "bulletproof" mine is 14yo,routinely maintained,good oil and gas (89-91 octane)

last fall replace the water pump and fuel pumps...no other problems

[Southfork]

I have that exact motor with hundreds of hours on it. Beast but loves gas