Don't know enough to know what to ask...

[mosaic13]

Just bought a lake house and with it came a '94 Jammer with a Johnson 70. That's about all I know. The previous owners took absolutely no care of the boat (it's been sitting in the water forever...old gas & oil, etc). But, I'm told the motor is only 3 to 4 years old. So, I'm assuming that the problem getting it to fire and run consistently start with dirty fuel, oil & carbs. I'm taking it to the marina but it'll be a good month before they even look at it. So, how can I tell what year the motor is? Are all Johnson 70's four stroke...four cylinder? I'd like to get a manual to at least learn a little about the motor. Any feedback would be awesome.<br /><br />Signed...I know nothing about outboards!

 

[mikeyzx2]

Re: Don't know enough to know what to ask...

welcome to iboats! there's a ton of things you can do at home with that motor and save you tons of money. first off give us a model number and we can go from there. it's likely a two-stroke, and it's probably a three-cylinder. get a manual, preferably a factory service manual. I got a Clymer, and it's ok but less detailed since it covers a wide range of years and HP's. Since it's been sitting the gas is worse than warm, flat beer and the carbs will likely be funky. also the water pump impeller is gonna need replaced and the thermostat too, otherwise you could burn the motor up. Overheating these motors is NOT a good thing. A well maintained motor will last many years. And change the sparkplugs, inspect the old ones and tell us what they look like, they can tell alot about the conditions of motor. Give us a holler back.....Mike

 

[Silvertip]

Re: Don't know enough to know what to ask...

The 70 Johnson is indeed a three cylinder, two-stroke, oil injected (meaning you don't need to mix oil and gas). However, make sure the oil injection is still functional before attempting to run the motor. Althought the pump may be on the engine, it may have been disabled to enable using a 50:1 gas/oil premix. If the external oil tank is present and hose is still hooked to the engine, it is very likely still functional.

 

[MGuckin]

Re: Don't know enough to know what to ask...

Great idea that you want a manual first.<br />The model number would be located where the motor is attached to the boat. Should be a plate or it would be stamped on the transom clamp somewhere. Look up the number here. Listed by horsepower. <br />It is not in English but very easy to figure out. Click on Modellguide.<br />Many places to get a manual from. iBoats does sell them among many others.

 

[umblecumbuz]

Re: Don't know enough to know what to ask...

Hi Mosaic,<br /><br />What Mikey says is sound advice. There are several very easy jobs that need to be done BEFORE ATTEMPTING TO RUN MOTOR. If you get yourself a manual - very important - then all those listed above require nothing except a few tools, a mite of common sense and a bit of patience.<br /><br />The big plus of doing these jobs yourself is the confidence it gives you when you're out there enjoying the results.<br /><br />Go for it.

 

[mosaic13]

Re: Don't know enough to know what to ask...

Thanks for the info and great advice. I'll be back at the lake on Friday and will locate as much engine detail as I can find. Now that I know the basic makeup of the engine I feel good about getting a useful manual to read up on. It definitely has the external oil tank in place and hooked up. One more thing...I don't have a trailer for this boat. I'm assuming that it's necessary to get it out of the water in order to do much of this work, correct? Besides, the pontoons need a good scrubbing. Need a used trailer. Any ideas as to where to find one? Perhaps Iboats.com!!! Any place else? Thanks again!!!

 

[Silvertip]

Re: Don't know enough to know what to ask...

You may be able to rent one for a day from your local boat dealer. Put the toon on blocks while you do the work, then rent it again to put it back in the water. By the way, empty the oil tank, clean the filter and fill with fresh oil. A gunked up tank is sure death to the VRO pump and possibly the engine.

 

[mikeyzx2]

Re: Don't know enough to know what to ask...

another thing that comes to mind, check the conditions of fuel lines, and when you get the boat out of the water go ahead and drain the oil in the lower unit, it's probably pretty saucy by now and needs changed. according to what the guys have said on here it would be a good idea to probably put new seals in the lower unit while dealing the water pump. to make things easy with the gear lube get a pump from the dealer (around $10) it screws into drain hole and is well worth it. there's a ton of things you can tinker with and it's a great learning experience.

 

[mosaic13]

Re: Don't know enough to know what to ask...

Update: Drained and replaced all the fuel including some fuel additive. Cleaned out the oil tank & put in fresh oil. Pulled carbs & gave them a thorogh cleaning. Replaced spark plugs. Put it all back together and after three tries it starts every time and idles normally!!! Runs very smooth. Still producing a little extra white smoke but not bad. I think it may just need to run for a while. Judging from the water shooting out the side it looks like the impeller is working fine, but I'm going to replace it anyway next weekend. It's definitely a '94 Johnson 70 3 cyl. two stroke. I'm ordering the manual today. Hope to take it for a spin this weekend. Any other suggestions??? Thanks so much...your assistance has been extremely effective and appreciated!!!

 

[Cricket Too]

Re: Don't know enough to know what to ask...

Change the lower unit oil and gaskets around the fill and vent screws, probably gonna do that anyway when you change the impeller, might want to change the whole pump if you see any wear on the plates. Do a decarb to clean up the rings and combustion chamber a little. Good motor, enjoy.