scoutXL: A problem that'll rack your brain

[doyouevenlift?]

Hey guys.

I've got a problem that'll make ya think so I'm looking for some insight. It's a Case Scout XL with a kawasaki 4 stroke OHV air cooled carbureted gas engine. The problem is fuel getting into the oil. But here's the kicker... it only happens over a long period of time, like months but it's way over full, half way up the dipstick. Now it was found the float was stuck so the carb was replaced along with the engine oil and filter. Later down the road it happened again. This time it was found the fuel tank vent was plugged. So the vent, fuel filter, carb, impulse pump (fuel pump runs off impulses from the engine), engine oil and filter were all replaced. Now it's happening again except there isn't as much fuel in the oil but there still is some. Fuel is pooling in the inlet of the carb which tells me the carb is over filling. Compression is at 80 psi when tested which isn't super and the tops of the pistons have heavy carbon. The fuel shutoff valve comes new with the carbs so it's good as well. The real basterd of the whole thing is the engine doesn't skip a beat it runs good which is even harder to figure out cause it eliminates alot of things that seem obvious as a problem but aren't. The spark plugs have been changed and gapped a couple times. The fuel is literally dripping off of the spark plugs. The power to the fuel shutoff solenoid was tested and its working properly. The jets come new with the new carb so those are new. Do you guys have ANY ideas? I'm straight up stumped

 

[doorfx]

Float needs to be adjusted b

 

[jjack]

Hey guys.

I've got a problem that'll make ya think so I'm looking for some insight. It's a Case Scout XL with a kawasaki 4 stroke OHV air cooled carbureted gas engine. The problem is fuel getting into the oil. But here's the kicker... it only happens over a long period of time, like months but it's way over full, half way up the dipstick. Now it was found the float was stuck so the carb was replaced along with the engine oil and filter. Later down the road it happened again. This time it was found the fuel tank vent was plugged. So the vent, fuel filter, carb, impulse pump (fuel pump runs off impulses from the engine), engine oil and filter were all replaced. Now it's happening again except there isn't as much fuel in the oil but there still is some. Fuel is pooling in the inlet of the carb which tells me the carb is over filling. Compression is at 80 psi when tested which isn't super and the tops of the pistons have heavy carbon. The fuel shutoff valve comes new with the carbs so it's good as well. The real basterd of the whole thing is the engine doesn't skip a beat it runs good which is even harder to figure out cause it eliminates alot of things that seem obvious as a problem but aren't. The spark plugs have been changed and gapped a couple times. The fuel is literally dripping off of the spark plugs. The power to the fuel shutoff solenoid was tested and its working properly. The jets come new with the new carb so those are new. Do you guys have ANY ideas? I'm straight up stumped

If the fuel level in the tank is below the carb__________Tank vent has to be pluged

If the fuel level is above the carb---------------------------Tank vent pluged and or the fuel valve is leaking

now you can also get fuel through the vac hose to your impulse pump.

Remove fuel to carb see if it leaks fuel if it does valve is leaking tank vent may be pluged

if not leaking reinstall pull off vack line to pump it should be leaking fuel fix the pump.

Your selanoid valve is actually a kind of secondary safty the needle and seat should not be leaking unless over pressured or set wrong

your plugs compression spark has nothing to do with fuel in the crank case.There is only 2 ways for fuel to get in the motor has to be one of them just start eliminating problems at the end will be your problem

 

[doyouevenlift?]

Shouldn't the float be set from factory? Both carbs that were put on were both bought from the dealer. Is it even possible to have 2 carb floats misadjusted on two different brand new carbs?

The fuel tank vent was replaced already and is still unplugged. The vent line was even all pulled off and blown out to verify there was no problems. The impulse pump (fuel pump) was replaced 3 times already as well.

 

[jjack]

You have to quit changing parts,its a waste of time and money.The fuel is getting in the motor from some where start eliminating possible problems.If its filling the engine when its not running just disconnect the vac hose for the fuel pump if any fuel comes out of that vac hose it,s the pump end of story.If that's good then check your fuel line motor off shouldn't be any fuel if there is check shut off valve,But like I said carbs really should,nt leat past needle unless under high pressure.or out of adjustment.check your vac line first and let me know what you find.We can figure it out just don't change any more parts.

 

[doyouevenlift?]

There is 3 ports on this pump. The fuel inlet from the tank, obviously there is fuel there. Then there is a short line from the pump straight to the #1 cylinder head which is where the pump gets the impulses from the engine to stroke the diaphragm in the impulse (fuel) pump, there is no fuel in this line so that tells me it's not getting into the engine there. Also if I remove that pump and blow into it with my mouth you can't feel any air in the other ports which is also good. Then lastly you've got the 3rd line going from that fuel pump to the carb which obviously has fuel. When the unit is shutoff there is no where for the fuel between the pump and carb to go so it just sits there. Does that fill in what you needed to know?

 

[doorfx]

Do you have an inline fuel filter ? If not and you have dirty fuel/tank every time you put a new carb on it it will get dirt in the needle and seat and not seal. Just like what is happening

 

[jjack]

There is 3 ports on this pump. The fuel inlet from the tank, obviously there is fuel there. Then there is a short line from the pump straight to the #1 cylinder head which is where the pump gets the impulses from the engine to stroke the diaphragm in the impulse (fuel) pump, there is no fuel in this line so that tells me it's not getting into the engine there. Also if I remove that pump and blow into it with my mouth you can't feel any air in the other ports which is also good. Then lastly you've got the 3rd line going from that fuel pump to the carb which obviously has fuel. When the unit is shutoff there is no where for the fuel between the pump and carb to go so it just sits there. Does that fill in what you needed to know?

yup then you have a carb issue,some carbs are shipped with a little holder for the float to stop them from moving during trans port,with the pump checked it has to be going in through the carb,pull a bowel off and see,just because a carb is new doent mean its set right,they are usually close but no garrenty on it.

Pull the carb off and try blowing fuel through it the needle should shut fuel the off.Also if theres no holder hooked to the float check the float for fuel inside the float.The floats could have a hole

 

[jjack]

Do you have an inline fuel filter ? If not and you have dirty fuel/tank every time you put a new carb on it it will get dirt in the needle and seat and not seal. Just like what is happening

that's anther possibility,good one,I just take it for grantit that there would be a filter but you never know for sure

 

[doyouevenlift?]

Where do they put this little holder for the float when it's shipped? I looked at it but didn't see anything. Also I found out the engine is not a kawasaki, very similar but it's actually a Briggs and Stratton.
Yes this unit has an inline fuel filter it is brand new and the fuel lines had been blown out. The fuel tank was also drained and inspected for debris in the tank.

 

[jjack]

Where do they put this little holder for the float when it's shipped? I looked at it but didn't see anything. Also I found out the engine is not a kawasaki, very similar but it's actually a Briggs and Stratton.
Yes this unit has an inline fuel filter it is brand new and the fuel lines had been blown out. The fuel tank was also drained and inspected for debris in the tank.

dosent mater what engine they all work the same,Usually its just a small pice of foam or plastic you would have seen it with the bowl off.If you have the bowel off the carb hold gently up on the float and blow throw the fuel line nothing should go throw ,slowly drop the float and air should pass tgrow the needle and seat