90 HP Johnson, Ieaking Injection oil in carb

[feagin]

I am a auto mechanic trying to repair an outboard motor and I sure do like I-boats.com.<br /><br />I am working on a 90 HP Johnson (or near that with a black cover v-4, 2-cycle.) that is leaking Injection oil into the fuel line and into the carbs carb. The motor was used once this year and is on a pontoon boat. I drained blue oil out of the carb drains. I used 1/2 can of starting fluid to start the engine and burn out the execive oil. It is running fine now and idles normal. <br /><br />Is it a bad oil injection pump, Oil tank vent, or other problem. I guess this could be a common repair job that I an not aware of. <br /><br />Thanks, Pat F.

 

[Frankhanhart]

Re: 90 HP Johnson, Ieaking Injection oil in carb

Hi Pat, give us the serialnumber/year of that engine. If it's a VRO I think it's supposed to mix oil and fuel in the carbs. The pros will be along to help you out, don't worry

 

[seahorse5]

Re: 90 HP Johnson, Ieaking Injection oil in carb

On pontoon boats, it is very common to have the oil tank mounted above the level of the carburetors, and that causes problems like you describe. The oil tank is supposed to be mounted below the carbs.<br /><br />The pump could also have a weak oil outlet check valve which would allow oil into the fuel system if pressure builds up inside the oil tank. The tank cap is only vented for vaccuum, not pressure, so some folks use a sharpened paper clip stuck up the hole inside the cap to puncture the sealing membrane. Then the cap is vented for both vaccuum and pressure.

 

[emdsapmgr]

Re: 90 HP Johnson, Ieaking Injection oil in carb

If the engine was run out of gas, it would flood the carbs with oil, as you describe.

 

[feagin]

Re: 90 HP Johnson, Ieaking Injection oil in carb

I thank All that replied to my post. I will check the oil tank vent hole and then see if it does this again because the bottom of the oil tank is mounted above the engine.<br /> If more oil does get in the carbs, is the check valve part of the VRO or can I buy one and put in the oil line to the VRO<br /><br />Thanks 'A Million'<br />Pat F

 

[seahorse5]

Re: 90 HP Johnson, Ieaking Injection oil in carb

<br /> If more oil does get in the carbs, is the check valve part of the VRO or can I buy one and put in the oil line to the VRO<br /> [/QB]

It would be new "VRO" time!