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  1. #1

    fx140 spewing oil help

    My in-law is having problems with his fx140. Went to help him with it. When I took the top of the air silencer off, the bottom part of the box around the fuel rail was full of oil.

    Started it up and oil is gushing from what I assume is the crakcase vent?? It is filling up so much that it was sucking oil into the air intake. I don't know much about these skis. Any ideas on what it is an how we can fix it???

  2. #2
    Sounds like it is way overfilled with oil. There is a breather hose from the oil separator that vents into the air box. If the oil level in the oil tank is too high, oil will vent through the breather hose into the air box just below the fuel rail. On that model you can only get an accurate oil level reading after the engine has been run and is HOT (on the hose you have to run it at least 12-15 minutes). It has a dry sump system.......not like a car, so you have to get the engine hot to check the oil level. Many, many posts of guys that incorrectly check the oil level with the engine cold, don't see any oil on the dip stick, add oil, then when they run the ski oil backs up into the air box, ruins the air filter and sometimes fouls the spark plugs.

    I'd suck out oil until it is just showing on the stick with the engine cold. Then run the ski, get it hot, and check it again. Shoot for an oil level about 1/2 way between the marks on the stick. This gives you a margin of safety, because you really can't get it hot enough on the hose to get an accurate reading. When you ride it on the water, run it for 20 minutes or so to assure it is at operating temperature, get off the ski, and check the oil while the water holds the ski perfectly level. This will give you the most accurate reading.

    If oil got on the air filter it will need to be replaced. If the ski runs poorly, change the spark plugs..........they foul easily, especially when there is excess oil.

  3. #3
    Thanks. I will try that. Could very well be th case. Also would bad compression cause the same thing? I read somewhere that it would.

  4. #4
    With really bad compression you could get some compression gas blow by into the oil which could possibly pump oil into the air box, but I would expect the ski to be running like crap, and smoking like crazy at that point. Minimum acceptable compression on that engine is 164 psi, and a healthy engine will have numbers close to or over 200 psi. Overfilled oil is the much more likely cause, unless the engine has high hours (over 500), or has not been maintained properly (stuck piston rings).

  5. #5
    Yeah is compression is bad. I didn't know what it was supposed to be, but I knew the ratios weren't good.

    Cyl 1- 150
    Cyl 2- 180
    Cyl 3- 160
    Cyl 4- 184

    I'm use to the 120 on my 2 stroke.

    Gonna try empting the oil and feeling it as you described. Maybe he can get through the summer before rebuild. He doesn't use it that much anyway. Thanks for the help.

  6. #6
    You might try running some Yamaha Ring Free Plus in the fuel. That will help eliminate carbon deposits on the rings and valves that may be contributing to the lower compression numbers. I'd do a shock treatment first (full 32 oz. bottle in a tank of fuel = 2 oz. per gal). Run through the tank then change the oil (this stuff pulls so much crap off the valves that it will contaminate the oil). Then check the compression numbers again. I've seen this stuff do miracles on outboard engines. It could save you a rebuild. Worth the 40-50 buck cost to find out. If the compression numbers improve significantly, I'd do a second shock treatment, change the oil again, then run 1 oz. per 10 gal. of the Ring Free for the rest of the season.

  7. #7
    This is how I run a jetski shop in the desert nmpeter's Avatar
    Join Date
    May 2008
    Elephant Butte New Mexico
    most yammies that show up here with oil in the airbox have been seriously overfilled. So many in fact I discuss it on my web site under the "do it yourself" page

    simply put you can't get all the oil out of a yamama 4 stroke..actully a little more then you need to forget the manual spec( which leads people to overfill the oil tank and put in what you've taken out ( typically 2-2.5 qauarts) then CHECK IT after running the engine on a hose for a few minutes). The air filer should be replaced..sorry..that's a pricey bit @ $80..I'd be shopping around for something generic on that.

    I'd be checking those compression numbers too 180 seems a bit high to me

  8. #8
    Thanks for all the help and advice. Going to try to help him out next weekend. Can the crankcase vent be re routed to an over fill tank?? That way when it is over filled again the air filter will not need to be replaced.

  9. #9

    Join Date
    Jan 2012
    Seems overkill to me, once the oil level is correct then all that needs to happen is the exact amount of oil that gets pumped out needs to be put back in, don't even bother checking the dipstick during the oil change. Much easier than trying to get the oil level correct based on the dipstick reading and then dealing with oil spewing out again if it's overfilled.

  10. #10
    This is how I run a jetski shop in the desert nmpeter's Avatar
    Join Date
    May 2008
    Elephant Butte New Mexico
    best to get the correct oil level ( and the correct area on a yam dipstick is pretty wide) anything else is less then best practice. It's not that hard. The unseen problem of overfill is oil frothing...which can reduce oil pressure significantly, you will not get a low oil alert immediate, buut you will be starving bearings for oil. Not a good way to go.

    don't cannot get all the oil out, so change what you can as often as you can afford to give the engine longer life.

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