ran bottom end dry

[Bruce.Turkeyho]

Looking to by a boat with 1985 johnson 75hp. Guy said he ran lower end w/o oil. had it fixed -new bearings and seals, pressure tested very good -claims to have all receipts. IS IT LIKELY that there is more damade to gears and shafts. he has it running. Any ideas as to what to look ot listen for or any experiance with this type of rebuild..much appreciated.

 

[jeff_smith_0423]

Re: ran bottom end dry

Really depends on how long he ran it without oil and how honest the mechanic was the rebuilt it. If you have other options, pursue them first and if not, proceed with caution.

 

[1946Zephyr]

Re: ran bottom end dry

Check to see if there are any filings in the oil and also spin the prop to make sure things spin smothly. Those are a couple good points to check first.

 

[mikesea]

Re: ran bottom end dry

perhaps you can get the seller to give you mechanic phone number,I want to think if a qualified mech.rebuilt the unit,the job was done right,taking a chance ,could put the mech.name on the line and also ,just as bad,put someone in jeopardy with serious possibility of a lawsuit if someone was hurt,in my experience,its usually the bearings that seize up long before gears go,NOT that it cant happen,just what I have seen.Chances are if it shifts smoothly,no knocking ,grinding its ok.As mentioned,if you are seriously thinking about buying it,ask the owner to allow you to pull the bottom gear oil plug for an ounce of fluid,then look for metal,you might even show up with a tube of oil and a big screw driver to do the job,Thats what I would do,.

 

[bob johnson]

Re: ran bottom end dry

"let the buyer beware"

bottom line


that low dollar carrot poisons a lot of people!!

in reality you are HOPING you will win the lottery..

in my mind all the aluminum casting housing pockets could have been damaged, if any of the bearings seized and spin the races
good luck

bob

 

[Bruce.Turkeyho]

Re: ran bottom end dry

Thanks for all the quick replys im on the way to check it out will get back..thanks for the thought about the alum casinging..didn't thinks about damaging the casing..will see if the mechanic is available too
Cheers

 

[Bruce.Turkeyho]

Re: ran bottom end dry

Back again...went to see the boat and motor last night on the way home..Turns out its a 1982 evinrude 75hp. Guy adv that the shop used a doner motor for bottom end as bearing had seized to shaft and scored casting. ( good call bob.) The mechanic changed some gears that were damaged and used doner parts to repair with new impeller , seals etc. mechanic set shaft to specs and it seems to run very well. No noises no vibration shifted fwd and rev w/o any noise. He had the carbs out and cleaned and new gaskets installed. Ran it for two mins on muffs, NO SMOKE, STARTED GREAT,it did seem to be idling a little to high though. I read somewhere else that the idel jets are on the front of the carbs(1985 model) at about 1 o'clock ( behind air breather) this guy didn't know how to adjust idle speed, said he thought they were self adjusting). Attached to the throttle linkage there are 2 indicator lines on the cam. 1) say "start" other is not marked..does anyone know what the second mark is for ? It has an electric choke. Also does anyone know how to adjust idle speed and will I find idle mixture screws behind the air breather if i pull it off..He said the motor compression tested at 125 , 115 ,125. I think that 8% range is alright ? I'll bring my own gauge to check. . Going to water test it sunday or monday and will comp. test after ride I will pull the plug and check the oil also
If it helps the model is a evinrude 75hp# TRLCNB.. SER# C7146377 .Master tech site had the TRLCN w/o the "B" as a 1982. Anyone know what the "B" indicates.
Thanks to all who posted its very much appreciated.
Bruce.

 

[kenmyfam]

Re: ran bottom end dry

You need to have the lower unit submerged to determine idle speed rather than on muffs. The back pressure is different with the muffs on and will not give you a true idle that you would get with the boat in the lake.
The "B" is just a suffix number. Info you gave shows the motor to be
75 HP
Power trim and tilt
20 inch shaft
1982

 

[Bruce.Turkeyho]

Re: ran bottom end dry

thanks for the reply and info ken, will see how it goes tomorrow.
B.

 

[Bruce.Turkeyho]

Re: ran bottom end dry

Back again...questioned the guy about the bearings and lower end. Said that there wasn't enough oil in the bottom end to get up to the top bearing and the top one seized onto the shaft. Used the doner shaft and new bearings top and bottom and seals, impeller etc. Said the bottom casing was not damaged just needed the shaft and swapped out best of both gear sets etc. from the two cases. I misunderstood his doner case explanation last time. He insists he only needed the shaft. I'm guessing he had a lower end seal that leaked and maybe water got it and oil leaked out while sitting.IS there going to be upper end damage from the bearing seizing onto the shaft ? A friend suggested that if the upper seal(s) are gone i should see signs of oil leak on the engine after a 20 min water ride, which should then be followed by me running ! Can someone tell me how the oil makes it up to the top bearing in an outboard. Thanks to all who have replied. I'm well versed with working on my vintage cars but new to the outboard motor experiance.
Bruce.

 

[jeff_smith_0423]

Re: ran bottom end dry

I cant' say for certain on an OMC, but the last mercury I was into had passages cast into the gearcase. As oil circulated under operating pressure, oil would move up and relocate what is called the pinion bearing in the Merc world. You could turn the propshaft and see oil bubble up next to the bearing.

I'm sure there are similar passages in an OMC gearcase.

 

[Daviet]

Re: ran bottom end dry

The vertical drive shaft has a spirl on the shaft that gets oil from the lower unit and moves it up the shaft when the engine is running. The only problem I have ever seen with the upper bearing is when the lower unit was run with oil.

For some reason people will drain the lower unit and leave it empty over the winter, and forget to fill it in the spring. I have seen this happen 2 different times.