mercury 850 thunderbolt removal/installation

[micky d]

Hi People.. just found this AWESOME forum .. from what ive read, there's some pretty nice ppl around!! good stuff..

i have just acquired a merc 850 thunderbolt from a friend, '77 i think, though i have to remove it from his boat and install it on mine.. my question is:

is there a trick to removing the tilt/trim motor and not having oil go everywhere? also, can the oil be 'locked in' and saved or do i dump it all and use new stuff?..

(and anything else i should know about removing/installing a motor!)

thanks in advance for any help & happy new year!

 

[erie_guy]

Re: mercury 850 thunderbolt removal/installation

Mickey,

To answer your questions. First disconnect the hoses and flare fittings from the tilt cylinders. If the hoses are hard, there may be pressure in the hoses- so loosen the fittings slowly. Engine should be in the down position when disconneting the fittings. You will probably loose some oil from the hoses, but this can be replaced when you change the oil, after installing the engine on your boat. The type of oil is either ATF or SAE 40 motor oil and prefered type is marked on a label on the side of the pump. Keep the hoses connected to the pump with the open ends higher than the pump and you should not loose to much oil during the move to your boat.

Be aware that the engine weighs a couple hundred pounds and a ceiling beam and come-a-long will make lifting the engine much less work. Put an eyebolt in the flywheel to lift the engine of the transom.

Once the engine is installed on your boat, drain the oil from the pump reservoir and refill with fresh oil. Once the hoses are reattached, you should purge air from the cylinders. The purge proceedures are described in a Mercury Outboard manual, which you would find valuable since the engine will probably need periodic maintenance and repairs.

erie_guy
Port Clinton, OH
1976 Merc 800 w/tilt and trim.

 

[micky d]

Re: mercury 850 thunderbolt removal/installation

Thanks my friend! everything i needed to know.. ive just gone from a 350 chev inboard to a clip on.. this will be different! cheers.. Mick

 

[Chris1956]

Re: mercury 850 thunderbolt removal/installation

Micky, It makes sense to put some plastic wrap over the ends of the hoses, when they are disconnected. It keeps the dirt out. If the oil that spills is blood red and clear, refill with Dextron ATF. If the oil is brown like motor oil, use some 5W-30 motor oil to refill. SAE-40 oil is too heavy for that PTT unit.