df 115 '07 making oil

[Triton33]

Hi all,

Have read quite a few posts abut this issue. I have all ready changed the low pressure fuel pump as a possible cause for this. Any other things that i need to check for in? Plan on doing a compression test. High pressure system(VST) is working fine.

Thanks

Jeff

[nelbur]

Suzuki has come out with a higher temp. thermostat so that the oil will heat up enough to boil off the gas. I have just bought one for my DF 140. They are not cheap but you only need one. Too much trolling and not enough running causes mine to make a little oil, but running at 5000 for awhile will bring the oil level back where it should be. It was much worse when it was newer. I now have about 275 hours on it.

[redlowrey]

Hi all,

Have read quite a few posts abut this issue. I have all ready changed the low pressure fuel pump as a possible cause for this. Any other things that i need to check for in? Plan on doing a compression test. High pressure system(VST) is working fine.

Thanks

Jeff

How do you know the vst is not holding it's level, there are only two places that fuel can get into the sump and you have fixed one of them. You don't have to be too smart to work this out, how well do you think an engine would run if it had raw fuel getting passed the rings into the sump, the cylinder would not be working for a start. Do you understand how the vst works.

[Triton33]

So if the VST float is not working correctly then gas would overflow I assume and get dumped into the block. Anyway of checking for this?

Thanks again

Jeff

[redlowrey]

So if the VST float is not working correctly then gas would overflow I assume and get dumped into the block. Anyway of checking for this?

Thanks again

Jeff

When the float can't control the correct height of the fuel it will gradually fill the vst, and because it is designed to suck vapour it starts to suck fuel up the small vapour line into the engine and mix with the oil. You won't know you have a problem because the engine will run fine it is only when you check the oil level you find a problem. If you would like to how the system works from the fuel the tank to the injectors just ask.

[Pleasureway97]

Late response, but try replacing pressure regulator

My DF140 was doing the same thing, with as much as a quart increase to the crankcase in about 10 hours of running. After considerable expense and guessing by different mechanics, a new one said that it would be the fuel pressure regulator. It turned out to be a correct diagnosis, as the regulator was putting out 70 lbs of pressure at what was supposed to be 35 lbs. Even the first new replacement regulator was faulty and had to be replaced. This took care of the problem.

[redlowrey]

My DF140 was doing the same thing, with as much as a quart increase to the crankcase in about 10 hours of running. After considerable expense and guessing by different mechanics, a new one said that it would be the fuel pressure regulator. It turned out to be a correct diagnosis, as the regulator was putting out 70 lbs of pressure at what was supposed to be 35 lbs. Even the first new replacement regulator was faulty and had to be replaced. This took care of the problem.

I doubt if you would have got a new faulty pressure regulator, you would have had an engine running rich and no fuel economy, more like you still had the same problem and they told you it was the pressure reg. Just to let you know the pressure reg is inside the VST.

[Pleasureway97]

Have the Fuel Pressure Regulator checked

I experienced this same issue for a long time. The shop where I last took my DF140 had to purchase a special tool/computer to verify that the fuel pressure well exceeded the recommended pressure. A new regulator took care of the problem.

[otisbrown]

oil problem

what color is your oil turning