2014 F300 bogs down and quits.

[Mytoolguy]

I hate to say it, but I do not see how air could get into the VST unless it was being sucked in from the lift pump side

I don't doubt it but what would cause the issue one time then run with no issues after. HP pump starting to go?

[99yam40]

I have no idea,
I was just saying you thought the dirty filter in VST pump was the problem so you replaced it.
the motor still had a problem with the new filter in place at 1st, so I do not think the filter was the problem original problem.

recirculation valve, a restriction, or sucking air may be , but it faded away.
it may come back just as easy.
I hope not

[Mytoolguy]

UPdate:

Took the boat out headed to our fishing spot about 9 miles away.
Ran out about 3K rpm usually faster but weather was a little of issue to go faster.
About 1/4 mile away port engine bogs and quits but restarts no issue.
Fish all day no issues

Get back to the bay had it running 4K - 4800 for an extended period of time without any hiccups.

Going to guess that the HP pump is intermittently starting to fail and will have one on standby to swap out.

Will report further as I use he boat more.

[oldmako69]

You might want to shop around. I had pump issues on my 225s and found aftermarket replacement that were significantly less expensive than orig equipment pumps.

[Mytoolguy]

You might want to shop around. I had pump issues on my 225s and found aftermarket replacement that were significantly less expensive than orig equipment pumps.

Thanks found them on Ebay from a place here in CA for $80 each with the filter and the upper grommet. Probably going to wait and swap until it gets considerably worse.

[oldmako69]

Smart. On the F225, the low PSI pump was 500 from YAM. I found a replacement for about 75. Never had an issue with it. The High PSI pump was another 500. I found a match for TWENTY BUCKS. Ran it for two years without a hitch.

So, keep your eyes open for parts. At some point, sanity has to enter the equation and risk/return decisions have to be made.

I am going to assume that there will be similar discrepancies with my new engines, 2014 Yam F300s.

[Mytoolguy]

Still having some intermittent issue doing the same thing. Going to change out the HP pump as I found doing some research as the HP pump starts to go bad they will tend to be a lot of debris from the pump brushed causing the filter to plug more often. While I'm doing the HP pump I figured I would do the low as well. That way it's all done and if I develop any other issues I can (hopefully) eliminate pumps from the equation. Once I swap and run I will report back.

[pstephens46]

I'm not convinced that you have narrowed this to a high pressure pump issue. Did you run it with fuel pressure guage attached while it was having issues? How do you know the VST is getting enough fuel in the first place?

[oldmako69]

Thanks found them on Ebay from a place here in CA for $80 each with the filter and the upper grommet. Probably going to wait and swap until it gets considerably worse.

Please post the link if you still have it.

[Mytoolguy]

I'm not convinced that you have narrowed this to a high pressure pump issue. Did you run it with fuel pressure guage attached while it was having issues? How do you know the VST is getting enough fuel in the first place?

I don't know. And it's intermittent now since the first cleaning so running my boat with a Pressure gauge isn't really the answer at the moment.

[Mytoolguy]

Please post the link if you still have it.

Turns out it's the wrong grommet and I had to use the one from the old pump. You can get these aftermarket pumps on ebay for $20 as I am 99.9999% sure yamaha is most likely getting them from another manufacture as well. Now that I have done it twice it's a pretty quick job and I have a complete VST with both pumps sitting as a back up.

Hope posting this link is ok

https://www.ebay.com/itm/Fuel-pump-6...Cclp%3A2334524

[oldmako69]

Perfect. Thank you.


One of my old engines (2005 f225TURD) had been running a 20 dollar High PSI pump for at least two years. I was able to cross-reference the part number somewhere online. That little pump is installed in all manner of cars, snowmobiles, motorcycles, outboards, etc.

20 bucks. What's not to like? One could argue that running a boat offshore or any distance really, demands a proper 500 dollar Yamaha pump. With twins, I was able to take that 480 dollar bet.

When the VST runs out of fuel, for whatever reason, that little pump is starved of fuel (of course) but is also robbed of cooling fluid. Now, I don't know how hot it gets in normal ops (or if it even does) but mine died the first year I owned it. I was constantly having to refill the VST with the squeeze bulb. I figured that I just cooked it and it died early. Just a guess.

[Mytoolguy]

For reference"
Just took apart the original VST model number on the HP pump is a Mitsubushi UC-T33 (which is the OEM pump) which is also used in the Outlander.
Running the boat a little later today will report back.

[oldmako69]

$822 from Boats.net

$38 from Amazon.

$27 from CarParts.com.


*These are quick numbers. Pay attention to the part number. My numbers might not be exact, but you get the idea. Same with the low-pressure lift pump.

[Mytoolguy]

Update:

Switched out HP pump ran good for a while then same problem happened only 2 time during the test run . Just seemed weird because I had it up to 5500 rpm and it didnt skip a beat.
Seem like it was fine took it out fishing to my spot about 9 miles away, little choppy got about 4 miles runing 20kts 3200 rpm and motor dies out...WTF?
putted around to our spots no issues on the way back in was doing it quite a bit more often.

Today I change the LP pump as well, and take it out for a test kinda windy so only about to run it about 4400 RPM but never skipped a beat, ran great no cutouts so I am guessing it was the LP pump having a hard time keeping up.

I'll keep monitoring and if anything changes I will report back but seems fixed (for now)...