1988 johnson 120 hp disabling oil injection

[silverfox1212]

Does anyone know the procedure on how to disable the automatic oil injection on this outboard? 1988 johnson 120 hp.<br /><br />thanks

 

[Dhadley]

Re: 1988 johnson 120 hp disabling oil injection

Welcome!!<br /><br />All you do is plug the oil line on the pump and unplug the wires. It sure is a nice feature. You sure you want to do that?

 

[silverfox1212]

Re: 1988 johnson 120 hp disabling oil injection

I just heard that if the vro fails it could blow the motor. I thought about just mixing my own mixture for safety. Have you had any experiences with vro failure on this?<br /><br />thanks for your help.

 

[Dhadley]

Re: 1988 johnson 120 hp disabling oil injection

Do a search on that subject. You'll find that the great majority of problems blamed on the oil injection actually had nothing to do with the pump. I run oil injection on all mine. Never had a problem. Of all the motors I've seen that had problems blamed on the oil injection only a handful actually did. And that was water in the oil tank. You cant hardly blame the pump for that.

 

[silverfox1212]

Re: 1988 johnson 120 hp disabling oil injection

Thank you for your help.

 

[Dhadley]

Re: 1988 johnson 120 hp disabling oil injection

Anytime!<br /><br />The only thing I would suggest if you do chose to run the injection is to buy the udated pump which is a straight mix pump. They list for less than 280.00. Either way thats a real good motor. Enjoy!

 

[silverfox1212]

Re: 1988 johnson 120 hp disabling oil injection

I have another problem and maybe you can give me some more advice. The engine max. rpm is 4800 I heard it is suppose to be around 6000 rpm. I decarbed it twice with sea foam. Did not help. Also, it seems starved for gas because the fuel bulb is not firm. I cleaned the line and took the air out and the bulb was firm for only 5 minutes. I am wondering if it is the fuel pump. Can I overhaul the fuel pump or do I need to buy a new one?<br /><br />thanks for your advice.

 

[Dhadley]

Re: 1988 johnson 120 hp disabling oil injection

First we need to make sure we have a good healthy motor. Lets start with a compression check. Then we need to verify its running on all 4 at all times. A check of the sync & link (including checking the wot timing) will verify that everything is as it should be there too. <br /><br />The bulb may not stay completely firm even though fuel is flowing thru it. While youre at wot push the key in to activate the primer. If it takes off (rpm-wise) and then bogs it is running lean. If it boggs without picking up then its OK.<br /><br />Has it always been at 4800 or did it run right once but not now? Has it been sitting? What boat and prop?

 

[silverfox1212]

Re: 1988 johnson 120 hp disabling oil injection

i am just a cadet, not very experienced. How do i check the sync & link and the wot timing? I just bought the boat it is a 16" Four winns. Just put a 19" pitch prop. It had a used prop I think 16 or 16 but it ran the same.The previous owner ran it it was not sitting.

 

[roypretty]

Re: 1988 johnson 120 hp disabling oil injection

i have a 1989 120 johnson vro on a 16 ft sunray express.my prop is a 13x19 and runs around 5000-5500 rpm at full speed no trim.works well with my set up.gets out of the hole well.