differences?

[raptorzx7r]

ok so i see the crankshafts are different between a force powerhead and a sportjet model, i have found a force powerhead, NON sportjet, can i use the block and other parts IF i use the correct crankshaft?
or will the block not even bolt up?
i am confused as i read where some say they have changed from one to another etc back and forth and others say it cant be done

 

[jerryjerry05]

Re: differences?

Try the FWC section there are a couple of guy that should be able to answer this.

 

[Frank Acampora]

Re: differences?

As I understand it, the crankshafts are balanced differently in sportjet and L drive engines than in outboards. BUT--I have never personally compared them. The blocks should hase the same mounting pattern and depending up[on the bore, (the 120 was made with 3.3125 and also 3.375 bore) all internal parts should swap.

However, Don't quote me as gospel on this one, Especially since it appears that the engine was swapped in.

There used to be casting numbers in the block, next to the head, up high by #1 cylinder, on the exhaust side. If you find that, Mercury service reps can tell you the year of the engine.

BTW: ANYTHING can be done if you are willing to throw enough money at it.

 

[raptorzx7r]

Re: differences?

where can i find out what the spline count is on the crank for the sportjet?

am i correct in thinking that the block, is a separate part from the lower mounting plate or adapter? i have seen what appears that on the sportjet the block slides down over studs in the jet pump, thru what appears to be an adapter plate, however the powerheads for outboard it appears the adapter plate has the stud in it instead. if that is actually an adapter plate i am seeing?

 

[raptorzx7r]

Re: differences?

i can find a PWC section but not a FWC.

i found a couple great deals id love to jump on before they are gone,,,,IF i can find out what will or wont fit....

 

[Frank Acampora]

Re: differences?

Earlier Force outboard engines have ten studs that are screwed into the bottom of the block. Six pass through the adapter plate and midleg while the front four pass only through the adapter plate and secure it to the front of the block. Six bolts pass through the front outside of the adapter and screw into the midleg.

Later Force outboards made by Mercury have the adapter plate screwed into the bottom of the block with ten bolts, Then the adapter is bolted to the midleg with six or eight long bolts that pass upward through the midleg itself.
So, in either case, the basic bolt pattern on the bottom of the block is the same. If you get one with studs, either double nut them (3/8) and remove them or buy a stud extractor

 

[raptorzx7r]

Re: differences?

thanks,
is there a difference in splines tho? apparently i need one with 13 splines and i have read they are not all the same? and that they are? confusing to say the least. even a call to merc tech was just as confusing.