74' merc 850 power tilt/trim

[Awc9372]

Hi, I'm new to this forum and boating in general and I must say this forum is full of information!
Anyways me and a friend are working on a 74' merc 850 and we want to convert it to a power tilt/trim. We already have the pump unit and the two cylinders. My question is what else is needed to complete the job? Also where to find such parts like the hoses and any additional mounting parts, limit switches, etc...

Thanks!
Andy

 

[kazek]

Re: 74' merc 850 power tilt/trim

hi.welcome to forum.you will need mounting brackets that cylinders mount to transom,2 of each hydraulic hoses:18-2110 and 18-2111 from sierra or ebay.mercury PTT mounting hardware.i am in the middle of putting same system on the motor.got hold back a bit in the process thou.bolts that mount the cylinders are SS 1/2" fine tread.i can give you dimensions later.hth

 

[Awc9372]

Re: 74' merc 850 power tilt/trim

Hey thanks a lot!
Ive found a set of brackets on eBay, will they work?

Mercury Bracket for External Trim with Tilt Tube | eBay

Thanks!
Andy

 

[kazek]

Re: 74' merc 850 power tilt/trim

That's the one.although instructions say there are 2 different installation procedures,(40 to 70 hp and 70 to 150 hp) i did not found any info about actual units being different.maybe some one can confirm that

 

[Chris1956]

Re: 74' merc 850 power tilt/trim

Those do not look like the correct PTT brackets. The ones in the first picture Kazek posted are the ones you want.

 

[kazek]

Re: 74' merc 850 power tilt/trim

Oh no.i am not selling those ones .see if u can get an info from seller on what hp motor and year bracket came from.

 

[Awc9372]

Re: 74' merc 850 power tilt/trim

Hi, could you give me the numbers on both brackets, and what other hardware Besides the brackets will I need?

Thanks
Andy

 

[Moody Blue]

Re: 74' merc 850 power tilt/trim

In addition to what you have mentioned already, you will need the three button control panel (or equivalent) and a mount of some sort for the pump. The mounts came in two styles, transom mount and floor mount.

There is also a long threaded stud about 5/16" x 16" that ties the two trim cylinder mounts to the motor midsection. Also you will need to remove the stock reverse lock feature of you motor so that the hydraulic system does not try to lift the motor when it is locked down.

There is only one limit switch that is built into the starboard trim cylinder mounting bracket. Most likely it is shot and the small spring in there is completely rusted away. Most people just bypass the limit switch. I went ahead and repaired mine because I like to have things work the way they were intended.

 

[kazek]

Re: 74' merc 850 power tilt/trim

starboard clamp with limit switch (#66083)has micro swich build in.switch can be replaced.starboard cylinder should have metal strip with adjusting screw.those all go on starbord side.port side clamp(#66084)is just plain as cylinder.any clamps from highier HP motors before 1980 with 2 ram system should fit.mine came from 1969 merc 800 found in boat scrap yard.
you will need operating buttons.typicaly its 3 button switch, but am sure it is possible to wire 2 toggle switches.one to operate trim and one to tilt after motor hits limit switch.
on your motor mount is 9 1/2" rod.5/16 in diameter which holds mountind clamps together.you will have to change that to 16 5/8" rod.can be all threaded made from stainless steel or aluminum.i prefer just ends of it threaded.bout 5/8 on the outsides.start soaking old rod now.they can be rusty.
1/2"-20 x 1 1/2"ss bolts are standard with your current shock set up and washers will be the same.they attatch to lower leg.
1/2"-20 x 2 1/2" ss bolts screw in where top of old shock was and this attatches the clamp
7/16"-20 x 3 3/4" hold top of new cylinder

sorry for delay.hth.could not make pointing arrows so look closlely

 

[Awc9372]

Re: 74' merc 850 power tilt/trim

Wow Thanks, now I know exactly what to get, will get back soon with pics and such

Thanks
Andy

 

[Awc9372]

Re: 74' merc 850 power tilt/trim

Hey guys, I've got one more question, what would be the part number for the rubber bushings that go in the end of the cylinders, and where might I look for them?

Thanks
Andy

 

[kazek]

Re: 74' merc 850 power tilt/trim

I think bushings are absolete.mercruiserparts.com,crowleymarine,if u want diagrams.here at iboats parts.thats a start.if you can get sierra catalog thats a plus(sweet talk hot lady working at west marine ).....eBay and oldmercs is the site/s

 

[kazek]

Re: 74' merc 850 power tilt/trim

Or u could make them your self from truck wheel chuck and post results if it worked.just an idea and no warranty or liability of the outcome.

 

[Awc9372]

Re: 74' merc 850 power tilt/trim

Hey guys, forgot about this thread... Anyways, I now have a complete operational tilt system! Thanks for all the advice guys!

Andy