115hp - 150hp trim/tilt swap

[danny9696]

Does any one know if the trim and tilt assembyl off my 75 115hp 1150 will fit an inline six 150 hp. my boat maxes out with 150hp.

Also does the lower unit interchange?

Found a great deal on this engine but it does not have the trim and tilt and just thought I may end up with some spare parts to swap if needed

 

[Chris1956]

Re: 115hp - 150hp trim/tilt swap

The PTT unit will fit. Those motors are essentially the same, except for the machining of the block, and perhaps the pistons are slightly different. The gearcases are identical. You do not need to switch them, uless one is bad.

 

[Chris1956]

Re: 115hp - 150hp trim/tilt swap

One more think. The last year for the Merc 150HP inline six was 1977. It was called a 140HP in 1978 and discontinued after that.

 

[Droll]

Re: 115hp - 150hp trim/tilt swap

One more think. The last year for the Merc 150HP inline six was 1977. It was called a 140HP in 1978 and discontinued after that.

• 150 hp 1973 > 1977 , crankshaft rated .
• 140 hp 1978 > 1980/81, crankshaft rated .
• 115 hp 1982 > 1988 above serial - 5829464, propshaft rated .

ALL these engines basically got the same power output.
Only difference between the 77 150 and 78 140 hp are it's decals .

Somewhere around 1979/80 the 140 got lower compression ( low dome pistons ) .
The only difference between the 140 and 115 ( propshaft rated ) are it's reed block configuration ( 140 uses 10/10 reed blocks, 115 uses 10/8 reed blocks ) + .050" ( rugh estimate ) lower exhaust port timing on the 115 ...


Arne Kjetil

 

[danny9696]

Re: 115hp - 150hp trim/tilt swap

you guys are great! I am glad to hear all this because I hate being stuck on land and this will save me time and money plus give me some harder to find back up parts!

This whole mess started with a bad force 125hp that decided it did not like the bearings on the crank shaft anymore, but that was before me, and then the 1150 I have has had a tapping noise in it since I got it and finally took her apart and found that it was not very well loved before me and needed the top three pistons replaced and block worked over, that kinda told me that someone did not replace the impeller when they should have but that?s ok I don?t mind getting a bigger engine! MORE FASTER when my wife is pulling me around the lake is ok with me!

 

[OldMercsRule]

Re: 115hp - 150hp trim/tilt swap

You may find that the 1150, (if healthy), has more of a hole and mid range shot then the 1500.

I had a 1976 1500, (fresh rebuild with 6 new pistons that I broke in and then sold after a bit), with PT that was cornsiderably faster, (at the top end 6,000 RPMs) then the 1979 115 I now have, (and have had fer 7 years), on the same 16 foot Jolly Roger low profile ski boat.

The 115 is much snappier and low and mid range (and lacks PT) or it may have been almost as fast at WOT.

The 115 is much better on fuel as well.

The 1500 had a bigger cupped wheel which helped aggrivate the weaker hole shot, but should not have hurt the mid range, (to be fair to the 1500).

My overpriced $.02. JR