1971 Mercruiser tilt problem

[pwheeler]

Greetings,<br /> I have just purchused a 1971 Larson Mercruiser 120/140 HP Sterndrive engine sn. # 3130019 that has been in storage for approx. 4 years. The engine is a 4 cylinder inline (GM Motor?)and looks to be very clean for its age. It has an hour meter attached that reads 61 hours(probably not true picture of total hrs). The only problem found so far is the hydraulic tilt will lower but not raise. The motor for tilt system sounds fine and is full of oil. Two wires that appear to be going into the outdrive are in need of replacing due to severe deterioration. Is this my problem and if it is how big of a problem do I have? Any simple way to fix so that tilt will raise?<br /> As mentioned above the boat has been in long term storeage. Appears to have been prepped or winterized prior to storage ie. freeze plugs removed, fuel removed from carb and fuel pump.<br /> I have changed the plugs,points,condensor and removed old fuel from tank. Is there anything else I should do? Is it safe to connect a garden hose to the lower drive and run engine and prop for short time? Will I need to do anything to the out drive due to long storage period?<br />Anyone know what the specs are on this engine? Is it a 120 HP or 140 HP?<br /> Thanks in advance for any advice on this relic.

 

[Elk Chaser]

Re: 1971 Mercruiser tilt problem

Your tilt problem is a wiring problem or sending unit problem, try and repair the wires as best as possible and see if that works first. The wires should be replaced.<br /><br />If I were you I would do a compression test on each cylinder just to be sure that everything is OK before you fire up the motor, if it looks wrong further testing may be necessary.<br /><br />Take a close look at all the bellows on the drive (gotta get the drive up first, hence the temporary fix) and make sure they do not have any cracks or holes and are in good condition. They should not be real dry to the point of being stiff or brittle. <br /><br />Chances are good that the bellows will need to be replaced which is OK considering you need to replace the tilt sending unit wires and also that it is a good idea to check the u-joints and lubricate them, checking the gimbal bearing is also a good idea when the drive is off as well as the lower unit shaft seal. (need a shop to do this unless you have an alignment tool)<br /><br />Other items to look at doing would be to change the lower unit gear lube. Lubricate all fittings you can get to. Engine oil and all filters. All hoses and belts. Check to be sure the shift cable is working properly and the drive is shifting correctly. (don't need to be on the water with a shifting problem) <br /><br />You can run the engine with ear muffs on but I would suggest that you do not turn the prop out of the water.<br /><br />An older boat needs to be gone through and you need to check things you can't see such as the u-joints and fix things such as the bellows because those items will cost much more money in the long run if they are bad or fail in the water.

 

[Blk-n-Blu]

Re: 1971 Mercruiser tilt problem

pwheel, Have a look at this:<br /> http://www.mercstuff.com/howdoi.htm <br />Good luck