1988 20 hp 2 stroke Mercury outboard

[tirebob]

Hey all,

Just picked up a little 14ft Princecraft with a 20 hp Mercury 2 stroke. Investigating the serial number, it looks like a 1988 model year. I have been trying to research it out on the internet but am not getting very far. I know it was pretty well taken care of (bought from my next door neighbour who is solid) but he hasn't run it now for a few years.

Other than a new plug and wire etc, is there some freshing work I should consider a "must do" before taking her out for the first time? Does anyone have any experience with these motors and know if there are any known issues to watch for?

I am not mechanically inept but all my experience is with cars and not boat motors so I would like to make sure I am doing everything I should...

Thanks in advance!

[Perchfisher]

Make sure to drain any old fuel out. Maybe replace fuel filter. Pick up some muffs so you can hook up a hose and run it at home. Make sure the water pump is working and enjoy your time on the water.

[PerchBuster]

Drain the oil from the leg through the bottom drain screw. Once emptied replace the drain screw and then open the top filling screw and fill her back up with Mercury gear oil. Doesn't hurt to flush it once too if it's been sitting a long time by running some clean oil in it and repeating the flush process after your first trip out. Add 2 new plugs. Wiring still could be fine. Fresh gas & Mercury 2 stroke oil and you should be good to go if everything else is ok. Add a fuel line filter to your gas line if you don't have one already. All of those older Merc's were pretty good in my opinion from my experience. You just have to love the smell of 2 stroke smokin in the morning lol.......:sHa_shakeshout:

[boonedocks]

Drain the oil from the leg through the bottom drain screw. Once emptied replace the drain screw and then open the top filling screw and fill her back up with Mercury gear oil. Doesn't hurt to flush it once too if it's been sitting a long time by running some clean oil in it and repeating the flush process after your first trip out. Add 2 new plugs. Wiring still could be fine. Fresh gas & Mercury 2 stroke oil and you should be good to go if everything else is ok. Add a fuel line filter to your gas line if you don't have one already. All of those older Merc's were pretty good in my opinion from my experience. You just have to love the smell of 2 stroke smokin in the morning lol.......:sHa_shakeshout:

I'm no small engine mechanic but isn't the top hole just a " weep hole" to aid in draining? I've always pumped the gear oil into the bottom hole until it comes out the top one to ensure that the leg is full and doesn't contain any air pockets?

[fishdude17]

I'm no small engine mechanic but isn't the top hole just a " weep hole" to aid in draining? I've always pumped the gear oil into the bottom hole until it comes out the top one to ensure that the leg is full and doesn't contain any air pockets?


You are correct boondocks

[EZM]

I'm no small engine mechanic but isn't the top hole just a " weep hole" to aid in draining? I've always pumped the gear oil into the bottom hole until it comes out the top one to ensure that the leg is full and doesn't contain any air pockets?

You are 100% correct - you fill from the bottom hole squeezing the new oil/grease into the gear box as all the remaining old oil/grease and water come out the top weeping hole.

You squeeze the filling tube until you see the new stuff coming out the top.

No offence to PerchBuster but that's not the correct way to do that. You are 100% right.

[JohninAB]

You are 100% correct - you fill from the bottom hole squeezing the new oil/grease into the gear box as all the remaining old oil/grease and water come out the top weeping hole.

You squeeze the filling tube until you see the new stuff coming out the top.

No offence to PerchBuster but that's not the correct way to do that. You are 100% right.

Better than squeezing oil in from the bottom is buying the pump that fits onto a one litre bottle and pumping the leg oil in thru the bottom hole.

Also, if you do not want to buy muffs, just use a garbage can and fill with water. Benefit is a lot quieter than running the motor on muffs to check the impeller operation.

[tirebob]

Thanks guys! I am going to try and do this all this weekend...

Also, the prop is a wee bit rough and has a little piece broken out of one flange. I was worried it might cause vibrations (thinking an effect like an unbalanced car tire ). Where around the Calgary/Airdrie area would be a good place to buy a new one?

[oilngas]

I'm starting to sound like a one trick pony, but to me all marine answers are at Auto marine in Calgary.

[tirebob]

I'm starting to sound like a one trick pony, but to me all marine answers are at Auto marine in Calgary.I saw their name in another thread and most definitely are on my list to check out!

[TROLLER]

Thanks guys! I am going to try and do this all this weekend...

Also, the prop is a wee bit rough and has a little piece broken out of one flange. I was worried it might cause vibrations (thinking an effect like an unbalanced car tire ). Where around the Calgary/Airdrie area would be a good place to buy a new one?

Take it to Stu at Propmaster on East Lake he can repair the existing one and sell you a new one. Should always have a spare in any case.

[tirebob]

Take it to Stu at Propmaster on East Lake he can repair the existing one and sell you a new one. Should always have a spare in any case.Already put a call into Stu and I was very impressed with his knowledge and attitude! He was totally helpful and explained in great detail a lot of stuff... I absolutely will be giving him some biz!

[YeeHaw]

Might be a hood idea to replace the impeller on it, cheap insurance.

[Kim473]

Take it to Stu at Propmaster on East Lake he can repair the existing one and sell you a new one. Should always have a spare in any case.

When you get the new prop / prop fixed, a extra shear pin is a good idea also if it has one. Hate to waste a trip because of a $5.00 part and 10 mins to repair.

At that age, I would replace the waterpump impeller. Cheaper than replacing a piston and stuff. Maybe $ 30.00. You can check Utube for how to replace. Should be easy. 2 - 4 bolts and the bottom end comes off, pull the old one out and new one in, put bottom end back on. Check Utube. Do this before changing oil.

I have a 1979 merc 115 that I have to do this spring, just have to get the boat into town from the cottage.