Basic 94' 115 Johnson Info

[Lawns570]

Buying a boat with a 94 Johnson 115 on that back. Currently I have 75hp Mercury.
I have no experience with owning a Johnson engine. Is this a 2 or 4 stroke. It has an external oil tank located with the batteries. How do I know if this is a 2 or 4 stroke. I've done a little research I see the thermostats can be a pain to change. Anything else I need to be aware of or info you guys can give me on them?

 

[interalian]

Need to post the model number. If it is actually a '94, it's a 2-stroke 'crossflow' engine. External oil tank is for oil injection (VRO), check to see if it's still hooked up. Many are removed and the motor run on pre-mix oil/fuel (50:1).

Look at the rear of the motor between the cylinder heads. The thermostat housing is at the bottom. If the plate between the heads is flat, thermostat replacement is not too hard, if it has a 'bubble' exhaust plate, changing the thermostats is a MAJOR pain. That said, thermostats (some call them 'vernatherm') are pretty durable. Be sure to check the bleed holes on the thermostat plate are clear or you'll get an air lock and overheat.

Need to be sure the water pump impeller has been changed recently - replace it if you don't know for sure.

Lots of other info around here. Check compression yadda yadda yadda.

 

[Lawns570]

Thanks I'll see if I can get the model number today. As of now I believe the oil tank is hooked up. Would you recommend unhooking it and mixing it myself?

 

[interalian]

All I'll say about VRO is if you're not 100% sure it's working, mark the oil tank (say, boat in the water and just you by the tank) and then run a few cans of gasoline pre-mixed at 50:1 through the engine and observe if the oil tank level drops accordingly - about 4-500ml per 25 liters of fuel burned. That way you're sure to have lubrication in the event it isn't working. Dropping levels in the tank will prove it's working so you can then switch back to straight gasoline. The extra oil might make it run more smoky than usual but shouldn't hurt anything.

 

[batman99]

Approx 3 years ago, I installed a 1995 Johnson 115 2-stroke on my 1996 Bayliner 16.5' Capri and its been running great since day 1. During its install, I also installed Fuel / Water separator and disabled the oil side of its VRO pump. Been using 50:1 premix and change its bottom end gear oil every year as well. For my Capri's Haul Design and loading, For tubing / heavy loading, I use 4-blade 15" and for long distance cruising, I use 4-blade 17". Aluminum Amita-4 blades for iboats store. Due to heavy stern of my Capri, it likes 4-blades best. When I bought the engine, its compression was 120-122 PSI range (which I told is great). IMO, OMC (Johnson) is very quiet engine, easy to start (if using Fast idle lever on its controls) and being a V4 design, likes to be within 3,800 to 4,400 RPM range - with max RPM in 5,500. To view the Johnson 115 engine running, surf: https://www.youtube.com/watch?v=rhVfNOL0NH0 Would I buy another 115 Johnson again? Without hesitation...


Hope this helps.

 

[Lawns570]

Thanks Batman. Can anyone provide me a link to a good quality fuel/water separator. The install looks pretty simply. Just install b4 the primer bulb. Should I then get rid of my standard fuel filter on the engine. I don't want to cause too much restriction... thoughts?

 

[Lawns570]

Also... this boat hasn't been run in a few years. I plan to..
Change plugs
Change filter
Change impellor
drain fuel
Clean carbs
-once running check to make sure oil is being fed in
Replace primer bulb and lines as needed
And now add a fuel water seperator.
Anything else I should do for a boat thats sat for awhile

 

[batman99]

The water / fuel separator I installed is:
- http://www.iboats.com/Fuel-Water-Se...4579701--session_id.997667103--view_id.485886
- http://www.rnrmarinestore.com/product_info.php?cPath=&products_id=58460738
Being 10 Micron filter, I left its little gas filter on its engine "as is" and installed the Water / Fuel Separator unit under its Stern cavity area. No fuel starvation since 18-7966 is also rated as high flow.

If your boat's steering is floppy, do investigate its cabling and mechanics as well. My boat's steering was very sloppy and to tighten it up, I had to remove its worn out tilt steering knuckle universal joint and install a new steering cable. Having steering with very little slop is critical.