Going from Force to Mercury

[puffitu]

Got all the electrical swapped and hooked up. Are there any precautions I should take in firing the thing up for first time since the block swap?.Are these 1988-1990 factory carburetors interchangeable? Reason I’m asking is my carbs seem to be in better condition

 

[jerryjerry05]

Should be an easy swap.
The only difference might be the jets?

You'd think they made thousands of these and yet they used different jets on some models.

IF???? you can get the model# for each motor, you can compare parts using the diagrams.
If not then taking them apart is the only way to tell.

 

[The Force power]

Hi Puffitu,

The information below was given to me, maybe it is of any help to you;

There were a couple dozen different carbs used on those motor.

Find carb part number, like
tc119a
tc107a
tc138a

Jet sizes for a 3 cylinder motor with 3 carbs are .070, .074, etc.

Jets for a 4 cylinder with two carbs are larger, .092, .094, etc.

Id the carb, then verify the correct jet installed for your altitude.

you can sort through all the carbs, and the corresponding jets per altitude, on
the mercruiser parts dot com web site.

Note, the top/middle/bottom carbs are not necessarily the same, and the jets aren't either.
Last edited by roscoe; June 26th, 2019, 09:30 PM.

 

[puffitu]

Thanks mtfbwy and roscoe
i was going to dig deeper on the issue this weekend. Today after work I’m hoping to get it all hooked back up. Fuel lines, filters and double check the carb linkage I may just leave the existing carbs on, only inspect the bowls, floats, needles etc. the thing ran really good with what’s on there.IF IT AINT BROKEN DONT FIX IT!...just inspect it

 

[puffitu]

Hey guys I’ve got all back together and getting ready to fire it up. Got the battery on trickle and triple checked I think everything I could possibly check. Now the gas in the boat (40 gallon and half full) is three weeks old with Stabil in it; it should be ok right?

 

[puffitu]

Is there any precautions I need to consider when trying to start this thing back up??

 

[jerryjerry05]

Just have a fire extinguisher handy.
Install a filter between the fuel pump and the carb.
Fram G2 G3 G12

If the choke setup is the same you shouldn't have a problem.

Compression and spark test.

Do a static timing.

 

[puffitu]

Success!! Got the new pre enjoyed engine running!!
checked compression and it’s got 120 on all 4 cylinders. Got great spark. I need to adjust the idle as it’s a bit low for in the driveway in a big bin. What a great learning experience. Thanks Jerryjerry05 and all that had input on this endeavor

 

[jerryjerry05]

One last thing: fill out the profile, fill out the signature, location, description of the boat.
This helps US when you ask questions.
Enjoy the boat.