replace Mercruiser 2.5L 1989 with Mercruiser 3.0 1994

[liusigou]

Today I bought a Mercruiser 3.0 1994. All cylinders pressure are higher than 145. I will remove old 2.5L and mount 3.0, then connect 3.0 to the old wires.is it easy? But I have found there are different between 3.0 and 2.5.

Can anyone help me to upgrade?

 

[Scott Danforth]

unbolt the old, bolt in the new

 

[Bondo]

But I have found there are different between 3.0 and 2.5.

Ayuh,..... Such as,..??

The long blocks are plug, 'n play,....
Differences in the accessories need to be dealt with,...

 

[liusigou]

I do not know where I should connect these two lines

 

[Bondo]

I do not know where I should connect these two lines

Ayuh,..... To the power steering unit, if there was one,....

 

[liusigou]

Ayuh,..... To the power steering unit, if there was one,....

It seems that both of thme are connected to the water in take? What happen if I just leave the two lines alone? water will leak?

 

[liusigou]

The serial NO. is 0B876780, The year is between 1988 ~1989. But my seller told me the year is 1994

 

[Scott06]

It seems that both of thme are connected to the water in take? What happen if I just leave the two lines alone? water will leak?

I am assuming your old boat does not have power steering and the new engine does?

the 8-10" long metal tube in the water intake hose is a powers teering cooler, this cools the PS fluid on the return line. Leave the cooler in the water inlet hose, remove the PS pump and 1/2" or so diameter hoses as you wont need them without PS

if you are swapping the complete engine it will be bolt in. just take the PS off if you dont need it

 

[kenny nunez]

Measure the distance between the rear mounting holes on the flywheel cover. If your original flywheel cover has a wider spread you are going to have some problems.

 

[liusigou]

Measure the distance between the rear mounting holes on the flywheel cover. If your original flywheel cover has a wider spread you are going to have some problems.

I have measured the length and width. They are the same dimension. Thank you

 

[liusigou]

How heavy is the motor 2.5 and 3.0? I just confirm the weigh of 3.0 is about 567 lbs (257.5kg)

 

[Scott06]

How heavy is the motor 2.5 and 3.0? I just confirm the weigh of 3.0 is about 567 lbs (257.5kg)

that sounds right fully dressed (exhaust accessories etc)

there is no real weight dif between a 2.5 and 3.0 they are essentially the same engine

 

[liusigou]

Does my motor work perfectly or something was hidden even I passed the pressure testing and running testing? I also checked the engine oil after the seller stopped running the motor He said it is golden color. but wr only run tbe motor maybe 5 minute with water cooling. Yesterday I open the cap of engine and I did not find the milk oil.

 

[liusigou]

I found the wires have been cut and I do not know Where I should connect it as in thr picture

 

[Bondo]

I found the wires have been cut and I do not know Where I should connect it as in thr picture

Ayuh,..... Gotta know where they come from, to tell ya where they go too,.....

 

[Scott06]

would agree where does the still connected end go...

being a pair like that my guess would be trim limit or sender. Sender ends up in the engine harness to get up to the gauge

 

[liusigou]

I have started my motor in my drive way. then 5 minute later I stopped it snd did the pteddure testing. To my surprise that pressure ate 130 130,128,130. but they were 145,155,165,150. Did the seller cheap me? I took all the spark plug off before testing