1990 60hp johnson vro fouling plugs.

[Fesstuss]

I have a johnson 60hp vro that likes to foul plugs. I can put a fresh set of plugs in and it will run like brand new for a few fishing trips and then it starts by surging on takeoff. Wot. Then starts getting worse by surging at wot at full speed. I can change the plugs and she's good to go for a few more trips, but this is starting to get expensive and aggravating. I rebuilt the carb last summer. Any help will be greatly appreciated. Thanks

 

[emdsapmgr]

What plugs are you running in it? QL77JC4's, L77JC4's or QL16V's? Any chance the engine is running cold? What cyl head temps does it run after idling for a while?
Is the spark advance feature functioning normally?

 

[boobie]

Check that engine temperature.

 

[Fesstuss]

I don't have a temp gauge but I can put my hand anywhere on the engine after running it a while. I am running ql77jc4 plugs. The model # is tj60tlesm. I am pretry sure that's what it calls for.

 

[Fesstuss]

Not sure about the spark advance. How do I check it?

 

[boobie]

It could be running to cold.

 

[tblshur]

i think they are right, stats stuck open, if not that i would mix some gas 50 to 1 and disable the oil side of vro maybe it putting too much oil in. you are using tcw3 oil good quality. good luck :joyous:

 

[Fesstuss]

Too cool? I can't say I've had that problem before. I have access to a handheld temp checker that has the laser on it. What should the temp read? It will be sat before I get a chance to check it.

 

[Fesstuss]

I have been hesitant to unhook the vro. One guy says unhook it and one guy says keep it. I think I'm gonna do away with it just for my peace of mind.

 

[Chris1956]

If you have an air leak in the gasoline supply line to the motor, the VRO pump will pump a lot more oil than is usual. You should see extra smoke in the exhaust. If this is what you see, check the gasoline line for air leaking in, at all fittings.

 

[Fesstuss]

What is the best way to check for air leaks? And what temp should my motor run?

 

[Fesstuss]

Where is the thermostat located? I took the little square cap off where I thought the thermostat should be and there is nothing there. Either the guy I bought the boat off of took it out or I'm looking in the wrong place. The only thing in there is a little rubber bushing type thing that says to thermostat. I took a pic but I can't get it to upload. Says the file is too large.

 

[Chris1956]

The motor should run hot enough that you can put your hand on the block, but not keep it there for more than a few seconds. To be more technical, thermostats open at 140*F. Your motor will run a bit hotter.

It is hard to check for air leaks, but inspect all the fittings to look for cracks, bad clamps etc. Some Johnnyrudes have a main strainer under the airbox. These can have a oring and a gasket. Make sure all are intact. The fittings on a "normal" fuel line are fuel tank pickup, both sides of the primer bulb, and a quick disconnect at the motor.

 

[Fesstuss]

Thanks Chris but I may have found the problem. Is the thermostat located on top of the head? I took the little square box apart and there is nothing in there.

 

[boobie]

Sounds like it. Go to shop.evinrude.com, look up your motor in the parts break down under cylinder and crankcase and you'll see the parts break down.

 

[Fesstuss]

Thanks guys. I would've never expected a cold motor. I wouldn't even thought to check. I will post back once I get the parts in and changed. You guys are awesome.

 

[boobie]

Let us know what you find.

 

[wildwalleye]

There should be a thermostat there, if not, that is more than likely your problem as when running too cold it will keep pumping max oil into the fuel. It eases up as the temp rises in motor.