'84 Johnson 70 Sitting longer than I thought

[Straightup]

I purchased a boat last winter. It is a Rinker 153V 1984 with Johnson 70 model # J70TLCRD. The boat never was stored outside a day of its life, was my brother in laws, and has less than 30 hours use on it. <br /><br />It turns out it’s been sitting longer than I thought. Hasn’t been run for 6 to 10 years. Boat and trailer are in exceptional condition, as is the engine, but just hasn’t been run.<br />I’ve done boat work in the past including all most all the work on my 1970 Larson IO that I sold in 2000, so I feel up to getting this Johnson up and running myself. Here are my plans for the engine. Please let me know if I am skipping anything or if anything should be done differently. Thanks.<br /><br />First I purchased a manual. Unfortunately, I couldn’t find the factory manual for my model of engine. Tried Ken Cook co. and a couple of others - they mostly said try Ken Cook. So I bought the Seloc manual that my engine fits into. Kind of a broad-brush stroke but has good info.<br /><br />Fuel in the tanks was varnish, it and the tanks were recycled and the old fuel hose thrown out. New Tanks, fittings, and line. Battery is junk, will be new.<br /><br />Have new water pump (complete kit with housing) on order. Did a search here and read many posts on impeller changes. From what I’ve read looks like the hardest part is getting the shift linkage hooked / unhooked and getting the old impeller off if it is stuck. Does that sound right? Will change lower unit gear oil as well.<br /><br />Will get new spark plugs, and the cylinders will be well oiled before gently rolling the engine over by the rope pull.<br /><br />Will clean carbs out and install new parts per carb kit. I did this on my Larson I/O. I am confused a little bit on the carb kit. Iboats has a carb kit for my engine, but I don’t know if that does all three carbs, or if I need to buy 3 carb kits? Will have to check.<br /><br />Fuel Pump? I noticed searching through old posts that several people recommended putting a new fuel pump on engines that have sat a long time. Was wondering if this would be cheap insurance to make sure I don’t end up dead on the water sometime. The engine looks like new under the cover, but I know 21 years is a long time. Looking forward to hearing any comments on fuel pumps.<br /><br />Thanks in advance for any tips / comments.<br /><br />Jeff

 

[marinemech1]

Re: '84 Johnson 70 Sitting longer than I thought

1 carb kit=1 carb<br />change fuel filter or at very least turn it upside down as original filter was installed upside down (threaded portion down is correct)<br />test warning horn turn on key ground brown wire coming out of head (note battery must be connected)<br />check thermostat for corrosion -replace?<br />on start up check for leaks due to gaskets drying up

 

[Solittle]

Re: '84 Johnson 70 Sitting longer than I thought

I would run it with an oil rich mixture for the first few hours say at 24:1 mix. Then run it at WOT for as long as you like. At that point it might be a good idea to do a compression check to establish a baseline for the future. Also at the end of the season you might do a decarb before you put it away for the season. Sounds like a real find.

 

[imstillatwork]

Re: '84 Johnson 70 Sitting longer than I thought

I got a hold of an 81 70HP that had been sitting for about 2-3 years and did exactly averything you suggested, plus drained the lower unit and refilled. <br /><br />After checking everythin about 6 times to be sure, I oiled the cylinders, rolled it over a few times by hand, primmed the fuel, and hit they key. It started first try, after about 5 seconds of cranking. <br /><br />Also did the 25:1 fuel mix and WOT for about 30-45 minutes as soon as I got a chance. It smoothed out a LOT after the WOT run.<br /><br />make sure your battery cables are good after sitting that long, and really make sure that your steering linkage isn't goin to bind up on you.

 

[Straightup]

Re: '84 Johnson 70 Sitting longer than I thought

Excellent info! Thanks. Will do all suggestions. Thanks for the tip about 25:1 mix. Hadn't heard that one.<br /><br />Jeff

 

[imstillatwork]

Re: '84 Johnson 70 Sitting longer than I thought

Expect it to smoke a bit more while doing this! Might want to save the new plugs untill after the 25:1 run also