No oil in tank '89 Johnson v4 VRO!

[deltaking]

I've been fishing so much lately and totally forgot to check my oil tank. I was out yesterday going at WOT and my motor started to quickly lose rpms down to idle and slowed down without me pulling back on the throttle and then eventually cutting out about 20 secs later. I checked the oil and there was none left in the tank. I got back and put some oil back into the tank and started it up again. It started fine. I took it back out and all seems well until I was running at WOT for about 1/2 mile and i noticed the motor slighly bogging and sounding muffled and decreased WOT speed of about 3-5 mph. I immediatedly decreased the throttle and didn't want to risk any potential damage. However after shutting it off for 5 minutes, it still starts and runs like normal except for the slight muffled sound and decreased speed at WOT.

My question is does my motor have an auto shut off if there is no oil? Also, what kind of damage could result from this? Could I have damaged the motor internally? Any help is appreciated! I want to get back on the water, thanks.

 

[emdsapmgr]

Re: No oil in tank '89 Johnson v4 VRO!

Your engine protects itself by sounding different audible warning horns depending on what the oiling problem is: Oil tank low oil warning: A 1/2 second beep every 20 seconds. No oil warning: a repeating 1/2 second beep on-1/2 second off. You need to verify that your control box horn is in working order. Did you reprime the oil system after filling the remote tank? Whenever there is a concern that the oil may have run out, you must re-prime the oiling system to get the new oil up to the pump. If the engine runs out of oil, it can cause the pistons to overheat, expand and lock up in the powerhead. First of all, check the compression on all cyls and verify the readings with any past readings. It is possible the pistons have become scuffed. I'd pull the heads and examine the cylinder walls, then pull the side bypass side covers and check the pistons skirts for any signs of aluminum transfer (scuffing.)

 

[rodbolt]

Re: No oil in tank '89 Johnson v4 VRO!

to answer your question, NO.
the system had a speed limiting overheat, depending on the model of the V4. but only audibles,if your horn actually worked, for low tank level or no flow.
most likly you have piston damage from lack of lubrication.
bummer

 

[kenmyfam]

Re: No oil in tank '89 Johnson v4 VRO!

Running without oil is never a good thing.
Do a compression check and see what you get.

 

[jonesg]

Re: No oil in tank '89 Johnson v4 VRO!

Different tone, slight speed loss, probably dropped a piston already.
You've very likely ruined a prefectly decent engine by not getting the manual and reading it. Ah well, thats boating.

 

[deltaking]

Re: No oil in tank '89 Johnson v4 VRO!

I checked compression today and all cylinders are good. What a relief. I haven't tried pulling the heads because I'm not confident enough to do major repair. Since the compression is good, what could be causing the muffled sound? Would it be damage to the pistons or cylinder walls? Is there anything I can check other than sending it to the shop?

 

[jonesg]

Re: No oil in tank '89 Johnson v4 VRO!

Something somewhere let go, maybe something on the exhaust side.

First do an ignition check, get the service manual and gap test it.
www.outboardbooks.com

You should set almost 1/2 gap on the tester and get a bright blue spark.
Get gap tester from any decent auto store for $12 max.

Fix the alarm system.

 

[emdsapmgr]

Re: No oil in tank '89 Johnson v4 VRO!

I would not run the engine till you have a look inside at the cylinder walls and the sides of the pistons. Esp, check to see if all the piston rings are intact.