3 in one question

[rsalvarez1]

I am new to this forum, and have a project, i own a mercruiser 260 ( SeaRay SRV22 ) and found a 2005 350 magnum mpi, i want to install it on the 1989 boat, as both are 350 and i am looking for fuel economy, i use the OTC scanner with the smartcraft carteidge and was able to read and diagnostic the 45 hours engine, then i connect the ecomonitor (ver 4.61 ) and the message is ENGINE UNKNOW, i have another boat a 2007 optimax engine, and connect perfect via the smartcraft connector ( blue and white wires ) On the ecomonitor, after the unknow engine message, another message sendme to settings, but nothing change, i think in espanish, i am sorry if the words are not the exact, but are 3 questions, 1- the 260 lower unit will be fine or need replace the gear ratio? 2- the ecomonitor must be programed ( old version ) 3 - the raw water pump can use the lower unit water from the impeller? i want to reuse the old exhaust and keep the closed circuit cooling..

THANK`S

 

[Scott Danforth]

gear ratio is fine
MPI wont get you any fuel economy over a carb....not a single drop per gallon internal combustion engines in a boat burn 0.4# of fuel per HP pr hr. fuel economy is controlled by the size of the load on the boat and how you command the throttle.
would need serial numbers, etc for your closed cooling and exhaust questions.

 

[alldodge]

OTC scanner with the smartcraft carteidge

Guess I need to look into this a but further, but so far all I'm findin is on ebay saying it works on Optimax and "some" Mercruisers above 2001. So its not reading everything and haveing trouble with others because of compatability (just assumng)

1- the 260 lower unit will be fine or need replace the gear ratio?

I think you will be fine, only thing that may need changing is maybe the prop to a higher pitch.

2- the ecomonitor must be programed ( old version )

The ecomonitor is usually part of the monitor. Which part number do you have?

3 - the raw water pump can use the lower unit water from the impeller? i want to reuse the old exhaust and keep the closed circuit cooling..

Assuming you have an alpha drive with your 260 motor. The alpha drive may not supply enough cooling for the newer motor. Adding closed cooling to an used open cooled motor has its own issues. Are you in slat of fresh water?

 

[rsalvarez1]

The OTC scanner with the smartcraft cartridge ( PERFORMANC PART 91880118031 ) works perfect, i plug it on a verado and optimax engines, and now this 350 magnum bravo fwc, serial 0W377840
The part number for the monitor is 8M0050764, work perfect on a 2007 optimax, but on the 350, show the unknow engine message

I am on the gulf of californa, salt water, i note all the tubing for a prime pump connected to the raw water pump, i can think that this bigger pump is for the new exhaust system and coolong, if i will not have an advantage ( efi vs rochester ) this 40 hp offer is not so atractive, advantage of read the mpg or gph on the new smart craft gauges can be adopted on the 260 with a flow meter, may be , i want more hp, swap the intake , i have to put all in a balance and look better

Thanks for your guide, the last option will be use the engine with the 260 cooling and verify the temperatue, 40 hp more will be lower cruising rpm's, fastest planing, fuel consumption will be sligh hig..

 

[alldodge]

Most of the HP gains on the new motor is from the vortec heads. Putting a 4 bbl intake on your 260 will increase the HP but at the mid to higher rpm. The hole shot would stay about the same

The intake on the new will not fit on the old one, they have different bolt patterns

 

[QBhoy]

Hi
firstly the MPI will give you better fuel economy over carb. Of this, there is no doubt.
Secondly, I have a feeling the reason you can’t pick anything up on the smart craft is that I think this engine maybe an EFI and not a post 2002/2003 MPI. The clever guys on here will be able to tell you if you post the serial number.
If I’m wrong and it is an MPI, you also need to fit a yellow terminator plug into the port for it to work. (If it came with a purple plug fitting.