HELP suzuki 140's "making oil"

[steve01]

I have a pair of twin Suzukis 140df motors and both seem to be making oil(fuel in the oil). The starboard one much more than Port. I have changed both thermostats and that didnt seem to help. Why would both motors have this isue at the exact same time?
Any other ideas? i have heard low pressure fuel pump? Vst? The motors are over 10 years old so i cant imagine the ring are not seating properly ?
has anyone experienced this before? Help is much appreciated.
thanks

 

[tykkyt e blue]

My 2006 250f yami has made oil since day one - I find some marked fuels are the cause. Dye addition makes some fuel get past the rings ( dye doesnt burn so left on cly. walls? )

 

[steve01]

thats interesting as it started doing this when i put "marked " gas in.

 

[Fishin'Zinn]

Check the fuel pump... If you squeeze the rubber fuel priming bulb and listen at the back of the engine (cowling off), you may hear it leaking, plus the bulb wont get hard (fuel pressure can't build because it's leaking). I doubt both of them are bad though. Maybe just a lot of hours and lower compression? They are still great motors, will run forever if you maintain them.

PS: for the DF140 if you haven't yet, check the "engine holder" (called that for some reason) plug, left side of the engine facing the bow, under the left leg panel (It's part of the exhaust galley). Suzuki put a steel plug in an aluminum casing. Ours just corroded through this year and we had to haul it out (didn't know beforehand) Luckily was able to get it cut out and welded vs buying a $1500 part! Really nasty thing, when it corrodes and fails, exhaust gas gets under the cowling, throws a map sensor code as you're sucking in the exhaust fumes through the intake.

This is exactly what we did. Haul out and ferry ride back to mainland after figuring it out once the $200 map sensor didn't solve the problem, I discovered the real issue! http://www.thehulltruth.com/boating-forum/395845-suzuki-df140-engine-holder-corrosion-fix.html

 

[steve01]

thanks for the info FZ will check this tonight.

 

[willydw]

Have a friend with a 300 Yamaha. Mechanic told him not to burn coloured gas.

 

[tigerprawn]

Check your thermostat running cold will allow fuel to get by the rings

 

[steve01]

thanks for reply guys, took my fuel pump off and squeezed the primar ball and gas leaked out of back of the piston(on the fuel pump).
It was leaking right into the crankcase. Guessing the diaphragm went on the pump?

 

[Fishin'Zinn]

^ Yup that's a known issue to happen on the suzuki pumps. Especially as they get older the diaphragms can crack and leak. Nice to hear you figured it out... I wouldn't think marine/marked gas would have that adverse of an effect, never heard of that before either?

 

[steve01]

Cheers thanks for the help/info FZ

 

[Last Chance]

Mine make a little when doing a lot of idling.. But sounds like you found your problem.

 

[steve01]

Mine make a little when doing a lot of idling.. But sounds like you found your problem.

what was the issue? rings not seating properly?

 

[Klob]

Or thermostats. Factory originals were made for warm water climates.