Change 2-cycle oil in remote tank?

Luke415

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Hello, I have recently purchased a boat with twin 1998 Mercury 150 XL 2 stroke engines. It was well maintained, including complete rebuild with new powerheads before it was stored for the past 5 years. Unfortunately I don't know what was done previous to storage (winterization, etc.), so I am trying to be very thorough with a spring tune up before I get it in the water.

If there are any knowledgeable mechanics that could tell me if I need to drain and replace the 2-cycle oil from the remote tanks that would be much appreciated. Both tanks are almost completely full and I would love to not have to buy 24 liters of new oil (almost 12 liters per tank). A local Merc shop told me I should change it since it has been sitting so long but I am trying to get a second opinion from an experienced owner/mechanic.

Thanks
 

merc850

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Did the type of oil have anything to do with the "complete rebuild" I would wonder? 5 years is a long time for oil to sit - where was it stored; inside?
 

dingbat

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Not worth the risk..... I'd change it and move on.

While your at it, I'd change the oil lines running to the motor as well.
 
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GA_Boater

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I doubt it has gone bad. But rather than throw it away, use some 50:1 pre-mix fuel in the gas tank to play safe. Do you know if the motors still need break-in? If you don't know, following break-in procedures wouldn't hurt.

The oil line replacement is a good idea,
 

Chris1956

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Gee, suck it out, inspect it for dirt and water, clean the tank and filter it. If it looks good, reuse it.
 

Luke415

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Thanks everyone for the replies. To answer your question, Merc850, the oil in the tanks has not been in since the rebuild, but it has been sitting for several years. The boat was stored outside, in Santa Rosa, CA. Since the rebuild, one engine has 85 hours on it, the other has 60 (apparently there is an auto shut off on one of the engines once the tank gets under 40 gallons, to conserve fuel).

I have talked to a few other experienced boaters, and I have gotten mixed replies. Most people have told me since it is in a plastic tank, and is almost full, that there is probably no to little condensation, and not to worry about it. I am going to do almost all of the recommended 100 hour and spring tune up procedures, including:

-Checking and changing any spark plugs that need it.
-Changing the air filter
-Changing all fuel filters/water seperator
-Changing oil filter
-Drain gas tank completely
-Salt-away flush
-New batteries (Old ones were bad)
-Take apart all connections with corrosion under engine cover, scrub with dielectric grease and reassemble
-Change lower unit oil
-Change all zincs
-Remove prop and check for any fishing line/foreign objects behind prop

Does anyone recommend any additional maintenance?

I am also concerned that one of the outboards lowered during transport. The locking tab that keeps the outboard in the up position came loose apparently, and it lowered during a 900 mile transport (I was not the one transporting). I was worried that there was a leak in the hydraulic lift/trim system, but it raises and lowers fine, and I cannot find any leak.
 

Luke415

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Apr 4, 2016
Messages
42
Thanks everyone for the replies. To answer your question, Merc850, the oil in the tanks has not been in since the rebuild, but it has been sitting for several years. The boat was stored outside, in Santa Rosa, CA. Since the rebuild, one engine has 85 hours on it, the other has 60 (apparently there is an auto shut off on one of the engines once the tank gets under 40 gallons, to conserve fuel).

I have talked to a few other experienced boaters, and I have gotten mixed replies. Most people have told me since it is in a plastic tank, and is almost full, that there is probably no to little condensation, and not to worry about it. I am going to do almost all of the recommended 100 hour and spring tune up procedures, including:

-Checking and changing any spark plugs that need it.
-Changing the air filter
-Changing all fuel filters/water seperator
-Changing oil filter
-Drain gas tank completely
-Salt-away flush
-New batteries (Old ones were bad)
-Take apart all connections with corrosion under engine cover, scrub with dielectric grease and reassemble
-Change lower unit oil
-Change all zincs
-Remove prop and check for any fishing line/foreign objects behind prop

Does anyone recommend any additional maintenance?

I am also concerned that one of the outboards lowered during transport. The locking tab that keeps the outboard in the up position came loose apparently, and it lowered during a 900 mile transport (I was not the one transporting). I was worried that there was a leak in the hydraulic lift/trim system, but it raises and lowers fine, and I cannot find any leak.
Is anyone familiar with this type of engine? I do not see any type of air OR oil filter. There is an airbox which connects to the carburators, but no type of filter inside. And I am not able to find an oil filter anywhere...

Thanks
 

82rude

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no air filter required as far as I know and you have a 2 stroke so no oil filter required either.
 

dingbat

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Is anyone familiar with this type of engine? I do not see any type of air OR oil filter. There is an airbox which connects to the carburators, but no type of filter inside. And I am not able to find an oil filter anywhere...

Thanks

No air filters on two strokes.

The "oil" filter is on the pickup at the bottom of the oil tank. The filter is replaceable but not designed as a maintenance item which is why I recommend draining the tank then clean, inspect and refill with clean oil before use.

I drain my oil tank every 2 years as a precaution against junk and water accumulating over time.
 

82rude

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Ahhh forgot all about remote tank filter.Ijust assumed he was looking on the motor.Man, sure wish I was close to a lot of you guys id have free oil forever.I was thinking that maybe he though it would have a spin on filter like 4 stokes.
 
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Luke415

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Ahhh forgot all about remote tank filter.Ijust assumed he was looking on the motor.Man, sure wish I was close to a lot of you guys id have free oil forever.I was thinking that maybe he though it would have a spin on filter like 4 stokes.
Thanks, Rude. Learning more about 2 strokes every day..
 

Luke415

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No air filters on two strokes.

The "oil" filter is on the pickup at the bottom of the oil tank. The filter is replaceable but not designed as a maintenance item which is why I recommend draining the tank then clean, inspect and refill with clean oil before use.

I drain my oil tank every 2 years as a precaution against junk and water accumulating over time.
Good to know, Dingbat. Appreciate the input.
 

dingbat

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Man, sure wish I was close to a lot of you guys id have free oil forever.
I easily go thru 20-25 gallons of 2 stroke oil a season. I have no problem dumping a 1/2 gallon or so in the waste oil tank every couple of years as a safe guard against blowing up a $18-20K motor. Still cheaper than dumping 5 quarts in the barrel every 3000 miles....lol
 

sam am I

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@ db,

Probably good thing to do but, I NEVER have done this and an "oz. of prevention" definitely applies here.........Are you seriously getting and/or seen crap/water in the oil screen/tank/system? From where and how?
 

Luke415

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Apr 4, 2016
Messages
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Thanks everyone. Does anyone happen to know the torque for spark plugs on these engines? I have the 1998 150XL offshore 2 stroke. Carbureted, aluminum heads. I'm assuming there is a specific torque...?
 

GA_Boater

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@ db,

Probably good thing to do but, I NEVER have done this and an "oz. of prevention" definitely applies here.........Are you seriously getting and/or seen crap/water in the oil screen/tank/system? From where and how?

This is a good question. Oil in a tank isn't like gas in a tank. And oil doesn't go bad like gas.
 
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