Need help asap. F250 fuel/vst issues

[TownsendsFJR1300]

Very informative thread!

A water cooled VST? If it is indeed, and it is clogged, could the fuel be over heating (besides other crap in the system)..?

Does this engine have a separate water / fuel cooler like the F150 too or just the VST?

[boscoe99]

Very informative thread!

A water cooled VST? If it is indeed, and it is clogged, could the fuel be over heating (besides other crap in the system)..?

Does this engine have a separate water / fuel cooler like the F150 too or just the VST?

Indeed that it is.

No separate water/fuel heat exchanger in the OP's model. Integrated onto the VST.

A Yamaha is not a Yamaha is not a Yamaha.

[boscoe99]

This is a tough audience.

[rodbolt17]

it would have to idle 20 or 30 min before you could overheat the fuel.
much above about 1400 the cooler isn't needed.

[cpostis]

Petersparker, Please post your complete model #.

Thanks!!

[petersparker]

F250uca and yes that is the plate I was referring to. I asked a Yamaha sales person for the gasket when I bought the filters and he had no idea what I was talking about so he got the onsite Yamaha tech and he had no clue either but they did pull it up on the parts diagram. Thanks for all the replies. I pulled the F filter and cleaned it out. Black soot. Couldn't see light through it when I held it to the sun. I cleaned it out with soap and water and a qtip. Put it back together and the motor ran much much better. I decided to put the boat in at the boat ramp so I can park it behind the house I am staying at. It is only a 1/4 mile ride. Idled nicely but when I got up to 2500 rpms it started to bog down. When I docked it behind the house I pulled the injectors. Of course it being Sunday I could not find any brake parts cleaner anywhere in big pine key. Gotta wait until the morning to clean them out. I did siphon all of the bad fuel out of the boat a few weeks ago.

[pstephens46]

F250uca and yes that is the plate I was referring to. I asked a Yamaha sales person for the gasket when I bought the filters and he had no idea what I was talking about so he got the onsite Yamaha tech and he had no clue either but they did pull it up on the parts diagram. Thanks for all the replies. I pulled the F filter and cleaned it out. Black soot. Couldn't see light through it when I held it to the sun. I cleaned it out with soap and water and a qtip. Put it back together and the motor ran much much better. I decided to put the boat in at the boat ramp so I can park it behind the house I am staying at. It is only a 1/4 mile ride. Idled nicely but when I got up to 2500 rpms it started to bog down. When I docked it behind the house I pulled the injectors. Of course it being Sunday I could not find any brake parts cleaner anywhere in big pine key. Gotta wait until the morning to clean them out. I did siphon all of the bad fuel out of the boat a few weeks ago.

Big Pine Key? Maybe Fairdeal can zip over and whip this thing into shape?

[petersparker]

Big Pine Key? Maybe Fairdeal can zip over and whip this thing into shape?

Got my fingers crossed hoping that cleaning the injectors does the trick. If not I will be open to all options. Here till Friday morning and would like to get out a couple times. Will update in the am

[99yam40]

It would be nice to know what the rail pressure was at when the problem shows up

[cpostis]

Yeah. Little out of my league on this one.
Looking at a F250txr diagram. It also shows an inline "t-shape" filter too. Who knows? Lots of places to clog.

Pstephens mentioned this filter(although you have a F250UCA). In review of this thread, I don't see where you checked/cleaned or replaced this particular filter. Have you?
Here it is (# 19) in your diagram.

[IMG]F250UCA.FIPump.Filter by Charles Postis, on Flickr[/IMG]

This filter, if partially clogged, will definitely cause the symptoms you have. Since you said "Vst was very dirty at the bottom", I would venture to say this filter is clogged.
Please confirm you got to/cleaned or replaced this filter. This may solve your problem for now. If you are confident enough you may go out while your in the Keys with the understanding you'll do a complete service later.

Go ahead and pull and check you FI's, however I would not pull your FI screens until I was sure I had replacements. Probably a good idea to send them out after your visit down in the Keys for cleaning/testing/rebuild (about 20 $30 each). Rodbolt mentioned a place he uses, I think Flagship Marine in Florida. Pull yours, send all with all their seals, o-rings, and screens, they'll match and after the rehab ship it back to you all new ones of these.

Confirmed Flagship Marine, here's their contact info:

Flagship Marine Engine Co. Inc.
200 E Ann St.
Punta Gorda, FL 33950-6006
Phone: (941) 639-3738
1-888-282-2840 TOLL FREE

[cpostis]

My mistake, I see you say you changed the filter in VST in your very first post. Doesn't mean it has not clogged again though.

[petersparker]

After I cleaned the injectors this morning I replaced the fuel lines. Motor fired up and sounded good. When I took it out I slowly picked up the rpms to about 4000. After about 10 seconds it dropped down and started to sputter. The boat was running(not great) and we were in the keys so we were going out. Did a little fishing and brought the kids to picnic island for a while. Put about 2 hours on the motor. On the way in I got it up to 5200 rpms for about 5 mins with no issues. It seemed like the more I ran it the better it got. Running at higher rpms the motor would drop down to around 2000 rpms and stay there until I backed down on throttle and slowly picked back up. I then decided to have my son step on the primed bulb when it was starting to sputter then it would pick back up keeping us on plane and quickly getting the rpms back up. Sounds to me like maybe fuel pump? Low pressure pump? Thanks for all the help.

[99yam40]

maybe sucking air