Johnson Pre Run Question

newbassboat

Seaman
Joined
Jan 30, 2006
Messages
53
I have a 1984 90 hp Johnson on a boat that I just purchased and I would like to know if there is anything I should do to it before taking it out the first time. It has sat around approx. 1 1/2 to 2 years since it was last run. I have Changed the Fuel Filter, Plugs, Plug Wires, and lower unit oil and added fresh gas. Am I good to go or am I missing something?
 

mitchell6

Petty Officer 3rd Class
Joined
Mar 24, 2006
Messages
93
Re: Johnson Pre Run Question

If it's been setting for around 2 years you may as well go ahead and change the water pump they need changing about every two years anyway
 

Brew2

Chief Petty Officer
Joined
Jan 12, 2004
Messages
427
Re: Johnson Pre Run Question

The only other I would suggest you do BEFORE heading out on the water is changing the impeller (water pump). Since they are made of rubber, they tend to get brittle and breakup over time. As a general maintenance procedure, most recommend that it be changed every couple of years. If it breaks up while you are running and the motor overheats, you will become the proud owner of a boat with a several hundred pound anchor attached to the back.<br /><br />If the motor hasn't been started in that couple years it has been sitting, I would pull the plugs, put a bit of oil in plug hole and turn the flywheel by hand a few times before reinserting the plugs. If a ring is slightly frozen, better to gently work it loose rather than break it.<br /><br />After yo
 

Brew2

Chief Petty Officer
Joined
Jan 12, 2004
Messages
427
Re: Johnson Pre Run Question

The only other thing I would suggest you do BEFORE heading out on the water is changing the impeller (water pump). Since they are made of rubber, they tend to get brittle and breakup over time. As a general maintenance procedure, most recommend that it be changed every couple of years. If it breaks up while you are running and the motor overheats, you will become the proud owner of a boat with a several hundred pound anchor attached to the back.<br /><br />If the motor hasn't been started in that couple years it has been sitting, I would pull the plugs, put a bit of oil in plug hole and turn the flywheel by hand a few times before reinserting the plugs. If a ring is slightly frozen, better to gently work it loose rather than break it.<br /><br />After your first run I would check the lower unit lube to make sure there is not water present. If not then you are good to go for the season, If there is, then you've got some work ahead of you do seal up the lower unit.<br /><br />I guess the other thing you may wish to do is overhaul the carbs. Depending on how diligent the person who "put away" the motor was, the carbs could be fine or they could be totally gummed up with varnish from old, untreated gas being left in them. You'll know for sure once you get on the water. If you are having problems keeping the motor going or accelerating, I'd look at the carbs first.<br /><br />Good luck and enjoy the first run!
 

newbassboat

Seaman
Joined
Jan 30, 2006
Messages
53
Re: Johnson Pre Run Question

Ok two more questions What type of oil in the plug hole should I use a spray (WD 40 or PB Blaster..ect) or just squirt some motor oil? and second how hard is it to change a water pump I have worked on automobiles a lot doing my own maintenance everything from changing the oil to changing a tranny but this is my first boat, but I do have a shop manual.
 

rickdb1boat

Supreme Mariner
Joined
Jan 23, 2002
Messages
11,195
Re: Johnson Pre Run Question

Use a spoonful of TCW-3 oil in the plug holes. The water pump is not bad if you have the Manual. Just a matter of unbolting the lower unit, disconnecting the shift linkage and dropping it down. Replace the pump and bolt it back up. If you run into any glitches, there is help right here to get you through it.... Here is a video that may help....<br /><br /> web page
 

newbassboat

Seaman
Joined
Jan 30, 2006
Messages
53
Re: Johnson Pre Run Question

Hey Thanks Rickdb1boat I think I can handle that after reviewing the manual and watching that video. By the way the video was good stuff where did ya get it?
 

rickdb1boat

Supreme Mariner
Joined
Jan 23, 2002
Messages
11,195
Re: Johnson Pre Run Question

It's from the themarinedoctor.com site. Lots of good info there.....
 

newbassboat

Seaman
Joined
Jan 30, 2006
Messages
53
Re: Johnson Pre Run Question

Well Rickdb1boat and Brew2 I got the Lower Unit off and have removed the water pump and impeller and it suprisingly looks very good, no signs of cracking or wear but since I already have it out and don't know how old it is I'll just replace it anyway, so as soon as I get the new parts I'll be ready to put her back together. Will I only need a Water Pump kit or do I need to order anything else to reassemble? Thanks for your help. I have another question on the lower unit there are a couple of really small holes one is located on the very front of the unit just above the nose piece (forgive me but I don't know the proper termanology) and one is located on the side kida positioned half way between the oil fill/drain ports. What are these holes for? I see no reference to them in my manual. Thanks again for your help.
 

newbassboat

Seaman
Joined
Jan 30, 2006
Messages
53
Re: Johnson Pre Run Question

Originally posted by newbassboat:<br />I am going to add this part of my question as another topic<br /><br />" I have another question on the lower unit there are a couple of really small holes one is located on the very front of the unit just above the nose piece (forgive me but I don't know the proper termanology) and one is located on the side kida positioned half way between the oil fill/drain ports. What are these holes for? I see no reference to them in my manual. Thanks again for your help." [/QB]
 

rickdb1boat

Supreme Mariner
Joined
Jan 23, 2002
Messages
11,195
Re: Johnson Pre Run Question

Just drain holes for water to seep out. Keeps the leg from cracking in freezing temps...Sounds like you're making good progress.. :)
 

16odaycapri

Cadet
Joined
Mar 29, 2006
Messages
6
Re: Johnson Pre Run Question

If your engine is VRO (oil injected) dissconnect the oil tank and mix the oil with your gas.<br />VRO stands for very rarley operates.
 

newbassboat

Seaman
Joined
Jan 30, 2006
Messages
53
Re: Johnson Pre Run Question

Hey 16odaycapri Thanks for the advice but the guy I bought the boat from already had it done. So I take it that was a good thing!
 

newbassboat

Seaman
Joined
Jan 30, 2006
Messages
53
Re: Johnson Pre Run Question

Hey Rickdb1boat the small holes are drain holes ok well the one in the very front just above the(nose) or what ever you call it appears to be plugged is there an easy way to clear the clog?
 
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