YM1700 injector timing question

[goose117]

Thanks for the input. Yeah there are some bubbles there at the outlet. I could try greatly reducing the tube diameter so any change is more visible. Your comment about not really seeing a change because of the small amount of fuel pumped per cycle makes sense.

There don't seem to be bubbles in the line from the fuel bowl to the pump and I did bleed the connection at the pump.

 

[bmaverick]

Thanks for the input. Yeah there are some bubbles there at the outlet. I could try greatly reducing the tube diameter so any change is more visible. Your comment about not really seeing a change because of the small amount of fuel pumped per cycle makes sense.

There don't seem to be bubbles in the line from the fuel bowl to the pump and I did bleed the connection at the pump.

I once ran the YM2610 out of fuel. I recalled Aaron's bleed procedure on YT. Watched the video and yes, these Yanmar fuel sipping machines make lots of power and use small drops of fuel to run.

While I was bleeding each line, I had to check and recheck as the droplets were not that big. Once done, The lines went back on. Started and cranked over normally. It's not like a gasoline engine where you would expect those injectors to shoot a large mist.

Could I also assume, you had downloaded the Yanmar 2T & 3T fuel pump service manual from the YTOG?

And, did you watch Matt's YT vid too,

 

[thepumpguysc]

U might b in the “starting fuel notch” with the throttle all the way open.. try pulling it back to half..

 

[California]

U might b in the “starting fuel notch” with the throttle all the way open.. try pulling it back to half..

What's that?

YM240 Manual says to start at full throttle but I never understood why, and actually use about 1/3 throttle before it catches.

Comments?

 

[goose117]

I once ran the YM2610 out of fuel. I recalled Aaron's bleed procedure on YT. Watched the video and yes, these Yanmar fuel sipping machines make lots of power and use small drops of fuel to run.

While I was bleeding each line, I had to check and recheck as the droplets were not that big. Once done, The lines went back on. Started and cranked over normally. It's not like a gasoline engine where you would expect those injectors to shoot a large mist.

Could I also assume, you had downloaded the Yanmar 2T & 3T fuel pump service manual from the YTOG?

And, did you watch Matt's YT vid too,

Thanks for the input. I don't have a good feel for how much fuel is involved per firing. I do have some recent videos of the spray patterns from the injectors. It looks like a lot but probably isn't. Here's a short video short injector spray.mp4

I have watched Matt's governor adjusting video a few times. I haven't seen anything about how this governor adjustment and the timing adjustment I'm attempting now together effect the overall injection timing.

I haven't seen the pump service manuals but will look for them. I have a 240D manual that came with the tractor.

 

[goose117]

U might b in the “starting fuel notch” with the throttle all the way open.. try pulling it back to half..

I tried a couple of different positions but it didn't seem to make a difference.

 

[bmaverick]

Thanks for the input. I don't have a good feel for how much fuel is involved per firing. I do have some recent videos of the spray patterns from the injectors. It looks like a lot but probably isn't. Here's a short video short injector spray.mp4

I have watched Matt's governor adjusting video a few times. I haven't seen anything about how this governor adjustment and the timing adjustment I'm attempting now together effect the overall injection timing.

I haven't seen the pump service manuals but will look for them. I have a 240D manual that came with the tractor.

Compliments of the YTOG, see attached. Wish the images were better.

Before ever tearing into the fuel pump, there are plenty of things not to touch if you never done this work prior, ask @thepumpguysc who's been in this thread from the start. He's a master rebuilder on these fuel pumps. Having the fuel pump, governor, spray pattern and timing all just so will make it all work together.

 

[goose117]

Compliments of the YTOG, see attached. Wish the images were better.

Before ever tearing into the fuel pump, there are plenty of things not to touch if you never done this work prior, ask @thepumpguysc who's been in this thread from the start. He's a master rebuilder on these fuel pumps. Having the fuel pump, governor, spray pattern and timing all just so will make it all work together.

Thank you! There is a lot of good information in there. One thing I noticed is that the delivery amounts are around 25 cc per 1000 strokes, or 0.025 cc per stroke. For my 1/2 in ID monitoring tube, 0.025 cc is only a length of 0.008 inches, if I multiplied and converted correctly. If I used a 1 mm ID tube I might get around 0.3 in or so of change in the length of tube fill. With a 0.5 mm ID tube there might be about 1.2 inches.

 

[thepumpguysc]

I think you’re thinking about this wrong..
The fuel is supposed to be flowing out of the #1 cyl under a bit of pressure, not under gravity flow..
And when the engine is turned slowly, it SHUTS OFF.
THAT is the “start of delivery”..

 

[goose117]

It does sound like I'm not following what is happening correctly. It seems like the fuel will flow out of my monitoring tube if I put the open end below the fuel tank level at least for some part of the engine's cycle. Maybe this is OK and I rotate the engine till the flow stops and this is when I check the timing? Is this closer? Thanks for all your input on this!