Outboard motor , non-valk

[da prez]

  1991 Evanrude , 6cyl. 3 two barrel carbs. I rebuilt the carbs last year and went thru the engine. The fuel system was full of oil from the injection system. This year , same problem. He ran the boat all summer and winterized it for storage. It is a no start. Pulled final filter and it was full of oil. Pumped primer with fuel line off until I got gas. I have to drain the carbs and start over.
                          Q  U  E  S  T  I  O  N.
 Can anyone enlighten me as to how the oil is getting into the carbs full strength.

                                    da prez

[sandy]

You don't say if this is an oil injected engine or a gas mixture engine. My thoughts on either version is that the gas is evaporating after shutdown, leaving oil behind. In the boats I've owned, I always disconnected the fuel line and ran the engine till it quit. This would burn all the mixture out of the carb(s) to prevent jets clogging.

[Blackduck]

Have had an Evinrude and a Merc both do the same thing. Both oil injected.
Think it just seeps past the oil pump, usually only gets the lower carb.
Been lucky with carb cleaner on the Evinrude but had to open the carbs on the Merc, mainly I think as the lower carb was not using fuel the cleaner did not get into it. Should have looked at draining the carbs then adding the cleaner. I took the inlet fuel hose off and poured a stiff brew directly into the carbs.
Maybe a case for draining the oil out of the tank if it is going to be stored for awhile.
Cheers Steve

[Steel cowboy]

Sandy, running the engine with the fuel line disconnected creates a lean out mixture. If it's a 2 cycle engines it uses the oil in the mix to lubricate the bearings. The engine uses the fuel/oil mixture to not only run but the oil as a lubricant for the roller bearings on the crank shaft, rods, pistons and cylinders. As the engine starts to starve from the fuel line removed, the bearings will run low of the lubricating oil the mixture carries with it. If it's oil injected than your better off just shutting it off when your done using it.
On my jet ski with oil injection, I removed the oil pump and delivery hoses. And went pre-mix. The mechanic I take it to (jet trends) adviced me to remove the oil injection system for peace of mind. And don't shut the fuel valve off until after I turn the ski off.
Just my advise...

[Led]

I know a lot  of Folks who disconnected the oil injection on the old two stroke "Enduro" bikes of the 70's,  and went premix with them.  Just ONE less thing to go wrong!!   No oil, equals a burnt down motor.  

In your case, it seems to be the opposite happening though!  Must be a batch of bad check valves in the oil supply pump??

[Pappy!]

Your engine (an older cross-flow engine) is fed oil by the VRO system. The large black fuel/oil pump on the side of the engine.
Older VRO pumps will get a leaky umbrella valve on the oil side and slowly leak oil into the fuel side, fuel line, and carb bowls.
I have dealt with this for years. It is what I do. You can either deal with it after a long period of non use or remove the oil tank in your boat, the VRO wire harness from the pump under the cowling and mix your fuel in the fuel tank at 50:1 and go on with life. Your choice. This is pretty easy to do and the VRO pump makes an excellent stand-alone fuel pump. Plug off the nipple on the pump where the oil line went...forgot to mention that. 
However....a side benefit to the oil issue is that the carbs stay super clean and will not gum up after a long period of non-usage (like a Valk). If you want to continue to use the VRO pump then simply open the bowl drains at the front of each bowl and pump fresh fuel from the primer bulb into the fuel system until the bowls are clear. Idle the engine for a while on the hose then run your season.
It is a good idea to pull your oil tank once in a while and drain it. Water and sediment additives from the oil will accumulate at the bottom. If you do this then disconnect the oil line at the engine and pump fresh oil through the oil line into a container until you know the line is fully purged of air. Again, simple stuff.

[da prez]

  Thanks for all the replies. I flushed the carbs last night and cleaned the plugs. It started and fogged for mosquitos . We are going to further check on the injection system and find a resolve.    Where else could I find an answer so fast.

                T H A N K   Y O U  A L L

                                                          da prez

[Pappy!]

  Thanks for all the replies. I flushed the carbs last night and cleaned the plugs. It started and fogged for mosquitos . We are going to further check on the injection system and find a resolve.    Where else could I find an answer so fast.

                T H A N K   Y O U  A L L

                                                          da prez

If you need any more information feel free....
I worked for Johnson/Evinrude engineering dept. for 22 years, directly and as an engineering liaison in the field.  Cut my teeth so to speak on those engines.

[da prez]

  A late update. Thanks to all and to Pappy. We removed the oil injection system and used mixed fuel. I told him to take it easy at first and if it runs ok , to give it hell. He took my wife along and after about five minutes , it cleared out and really ran. His son was able to ski. He said the boat has not run this well in 20 years. There is no problem pulling up a skier.

                       T H A N K   Y O U   A L L.

                                                                  da prez

[sandy]

I understand your theory about starving oil but my experience is different. In my lifetime I've owned Evinrudes and Johnsons. Sizes were 2.3-3-8-18-115 and 135 HP engines. I treated all of them the same(running till they quit after removing fuel line) andnever had any motor problems.

Sandy, running the engine with the fuel line disconnected creates a lean out mixture. If it's a 2 cycle engines it uses the oil in the mix to lubricate the bearings. The engine uses the fuel/oil mixture to not only run but the oil as a lubricant for the roller bearings on the crank shaft, rods, pistons and cylinders. As the engine starts to starve from the fuel line removed, the bearings will run low of the lubricating oil the mixture carries with it. If it's oil injected than your better off just shutting it off when your done using it.
On my jet ski with oil injection, I removed the oil pump and delivery hoses. And went pre-mix. The mechanic I take it to (jet trends) adviced me to remove the oil injection system for peace of mind. And don't shut the fuel valve off until after I turn the ski off.
Just my advise...

[cookiedough]

I understand your theory about starving oil but my experience is different. In my lifetime I've owned Evinrudes and Johnsons. Sizes were 2.3-3-8-18-115 and 135 HP engines. I treated all of them the same(running till they quit after removing fuel line) andnever had any motor problems.

Sandy, running the engine with the fuel line disconnected creates a lean out mixture. If it's a 2 cycle engines it uses the oil in the mix to lubricate the bearings. The engine uses the fuel/oil mixture to not only run but the oil as a lubricant for the roller bearings on the crank shaft, rods, pistons and cylinders. As the engine starts to starve from the fuel line removed, the bearings will run low of the lubricating oil the mixture carries with it. If it's oil injected than your better off just shutting it off when your done using it.
On my jet ski with oil injection, I removed the oil pump and delivery hoses. And went pre-mix. The mechanic I take it to (jet trends) adviced me to remove the oil injection system for peace of mind. And don't shut the fuel valve off until after I turn the ski off.
Just my advise...

Me too,  at end of season ONLY though run it awhile in my yard with water hose hooked up on lower part of motor in a 32 gallon trash can full of water and run it for 3-4 minutes then disconnect the fuel line and spray into each carb (mine 40hp mercury has 4 carbs) mercury storage seal spray until the engine finally sputters and dies after a minute or so.  Creates tons of smoke but seems to work. 

[Steel cowboy]

That fogging oil is coating the insides, the crank bearings, rod bearings and piston wrist pin bearings as well as the cylinders. On your 2 cycle outboards the bearings look the bearings in a u-joint cap. On a 4 cycle engine the fuel lubricates the upper cylinder, too lean and you can burn a piston and scorch the cylinder walls.