TrimNTilt for 74 85hp

vegard

Petty Officer 2nd Class
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Jun 7, 2003
Messages
168
As you can see from my other posts, I am repainting a 1974 Johnson 85hp. I would like to upgrade to trim and tilt while its all apart. I want to find a used unit to put on there, fairly cheap... Where do I look?
 

vegard

Petty Officer 2nd Class
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Jun 7, 2003
Messages
168
Re: TrimNTilt for 74 85hp

It seems like the pre-79 OMC units are very hard to find. Is it possible to adapt a unit from another year? how similar are they? Can anyone tell me the difference? I work as a machinist, so I can make any pieces necesary. I assume that I would need the whole transom bracket, then adapt the steering tube to fit my engine... does this sound right? I am unsure of how all this goes together, but I am confident that I could make something work. Any ideas here?<br /><br />Thanks
 

bubbakat

Captain
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Oct 29, 2002
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3,110
Re: TrimNTilt for 74 85hp

Vegard DJ is giving good advice here on those years. I have an 85 h/p 1975 evenrude and kept having trouble out of the original t$t so I ordered a pt 135 right here off iboats and am very pleased with the unit. Its easy to mount and operations is smooth. It sets back about six inches and allows the prop a more solid bite in the water to just another plus in my opinion
 

vegard

Petty Officer 2nd Class
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Jun 7, 2003
Messages
168
Re: TrimNTilt for 74 85hp

Yeah, I understand that would be the best option. I do not however want to put that much money into the motor. I also would like a new project to work on. I wonder how similar the different motors are. I can spend alot of effort on this, so I dlike to give it a shot, if it looks feasible.
 

ledgefinder

Ensign
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May 2, 2002
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916
Re: TrimNTilt for 74 85hp

The pre-1978 rams replace one or both of the shock absorbers in your transom bracket. The pump/motor bolt to that triangular boss with three tapped holes on the outside of the starboard (port?) bracket. This triangular boss in on all the larger OMCs (55hp+) from around 1968 to 1978, and the tilt from any of them (except the 1977 135) should adapt to your motor.<br /><br />Some (all?) of the early units are designed to be power tilt, not trim - by which I mean the unit isn't intended to overcome the outboard's thrust at high throttle. You therefore have a system which will tilt the motor at the mooring, and at low throttle as you motor through shallows, but which depends on the metal trim rod for it's final trim setting at high throttle. <br /><br />The tough part of using these is getting the rams into your transom bracket (and out of the old bracket). On top there are two bolts, and on the bottom a metal rod goes all the way across. You need to press the bolts & rod out. Heat & a shop press are probably the ticket. <br /><br />I iboats can't help you out, I have the original equipment unit from a 1971 125hp (jslobvan@exit3.com).
 

vegard

Petty Officer 2nd Class
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Jun 7, 2003
Messages
168
Re: TrimNTilt for 74 85hp

This is interesting. Now we're getting somewhere!<br />So, I wonder... If I get a tnt unit from a newer model, including everything from the transom to the steering mount (the piece with the hole for the steering pivot tube) can I adapt the rest to fit? <br />Do the newer motors mount to the steering bracket in the same way as mine does? (with the rubber isolators and the top and bottom "forks"?) is the steering tube the same diameter?<br />I feel very hopeful right now. I looked at some pictures I found on the internet, and it doesnt seem impossible. <br />Anyone have a couple different motors on hand to compare? (maybe even take some pictures?)<br /><br />If someone with the right motors on hand could supply me with some measurements and pictures, I wouldnt mind making two of whatever parts are necessary to make the whole thing work (if it works) and send them a set.
 

vegard

Petty Officer 2nd Class
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Jun 7, 2003
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168
Re: TrimNTilt for 74 85hp

Just to give you guys some info...<br />I am a very capable machinist, and have mill and a lathe at my dispoasal, as well as lots of other stuff (presses, etc...) I also run CNC machines, although I cant use those for this project.
 

bubbakat

Captain
Joined
Oct 29, 2002
Messages
3,110
Re: TrimNTilt for 74 85hp

vegard I will get out my camera tomorrow and take some pic of the addon tnt that was on my 85 and e-mail them to you with the measurements<br /><br />What I like about the new one I have it doesn't matter what motor I change to it will still work on it
 

vegard

Petty Officer 2nd Class
Joined
Jun 7, 2003
Messages
168
Re: TrimNTilt for 74 85hp

Ledgefinder tells me that it might be a possibility to exchanget the entire mid-section with a later engine to get tnt. Can anyone confirm this?
 
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