Difference in mid-tower in a 1979 140 and a 1985 90?

[79Merc140]

Hey:<br /><br />Is there a difference in the mid-tower of a 1979 Mercury 140 and a 1985 Mercury 90? <br /><br />The reason I am asking is, I have a 79 140 with the old style power tilt/trim system. I am buying a 1985 90hp with low compression on #1, basically because it has the new style power trim/tilt intigrated in the transom bracket. Would I be able to mount the 90 mid-tower and possibly lower unit on my boat and bolt the 140 powerhead to it? Or is there something different in the mid-tower between the 2??<br /><br />Thanks in advance.<br /><br />Craig

 

[Texasmark]

Re: Difference in mid-tower in a 1979 140 and a 1985 90?

Why not mosey over to your friendly Merc dealer and see if you can't buy the head mechanic lunch for the priviledge of brousing the parts lists on these 2 engines. Carbs, jets, pistons (maybe) front and rear castings and reeds should be about all you need to look for. I think both are 99 cu in so the basic parts should be identical; just the things that would get more whoopie out of it would be different: fuel delivery and porting.<br /><br />One thing though, I had a '89 tower that was "Direct Charged" (Merc's fancy name for quasi loop charging) The older engine (or both) may not have it and it could make a difference on performance. Don't remember when it was introduced in the towers. Check the pistons for similarity. If no port in either, you don't have to worry about it. If one has a port, you can expect better performance and higher fuel efficiency.<br /><br />Mark

 

[Clams Canino]

Re: Difference in mid-tower in a 1979 140 and a 1985 90?

Because his answer is here and I'll take the free lunch?<br /><br />Your answer is YES - you can do exactly what you want to do there. NO problems.<br /><br />-W

 

[79Merc140]

Re: Difference in mid-tower in a 1979 140 and a 1985 90?

Thanks Clams, that's exactly what I needed to know.<br /><br />Thanks also TexasMark, but I never had any intention of using any part of the powerhead from the 90, just the mid-tower to mount it on. What I was after was the power trim/tilt from the 85. I like my 140 and it runs good.<br /><br />Craig

 

[Texasmark]

Re: Difference in mid-tower in a 1979 140 and a 1985 90?

Good luck dude. May the force be with you. Grin.<br /><br />Ok Clams, do you like fried shrimp or lobster for lunch? NAUCHO'S???????, with beer????? Grin.<br />Mark