Fuel starvation yamaha f225

[rodbolt17]

ok
you DO NOT and DID NOT have a VST issue.
you DO have a lift pump/leak issue.

if the VST has no fuel the engine quits.

just like your car will when the gas tank is empty.

find the VST supply issue.

the fuel cooler is rather simple.
its a big aluminium block with two tubes.
one tube has water flowing the other tube has rail return fuel flowing.

it is not your supply issue.

[99yam40]

ok
you DO NOT and DID NOT have a VST issue.
you DO have a lift pump/leak issue.

if the VST has no fuel the engine quits.

just like your car will when the gas tank is empty.

find the VST supply issue.

the fuel cooler is rather simple.
its a big aluminium block with two tubes.
one tube has water flowing the other tube has rail return fuel flowing.

it is not your supply issue.

I had to read this a couple of times before I got that it was the fuel cooler,
right?

could that gasket he found leaking been his problem?
I do not see how this would keep the VST from filling, but can see where the leak could keep the rail from pressurizing maybe.

I removed the vst pump today and I believe the gasket was leaking ( between the housing and pump) took everything apart and cleaned it.

[marchmadness]

The failure was the vst relief valve. Like rodbolt said if there is any leaks in the system it leads to a loss of fuel or maybe I just got lucky and I found something else. But all seems to be good right now. I would like to thank all on this forum . you are a good knowledgeable bunch.

[marchmadness]

Here we go again same issues back I took the boat out for the second time. I ran the boat all of last year without any issues,,,,, I'm not sure of what else to do..

[fairdeal]

I have a pair of 03 f225 .
After i run the motors and get them hot i shut them down for about 20 minutes.
Start them , when I throttle up the port engine dies.
I pump the gas bulb starts and runs.
This only happens to the port motor .
If i don't shut them down there is no issue.

this same problem?

[marchmadness]

Last year same time I changed the pressure relief . Rest of the year ran fine . Yesterday the same exact issue. Sat for an hour fishing started right up and then died . Ball soft pumped it and was on my way. I’m ready to cut the bolts off and say good by.

[marchmadness]

Could tilting the motor up do anything? The day before I had them tilted up ! I’m desperate

[fairdeal]

seems either
- your VST is already near empty at the point you shut the engine down - or
- the entire VST contents are boiling off through the vent while you sit

I don't like the second - because that "should" cause flooding and a hard restart. But....

Anyway, I would put some effort into testing the low pressure fuel system:
get the boat on land, remove the intake silencer, and get set up to manually switch on the LP pump

- tee in a vacuum gauge to see if there is restriction on the suction side (should be virtually nothing)
- tee in a pressure gauge on the discharge side (should be seeing ~15 psi with the VST full)
- if not getting good pressure / flow, swap in a piece of clear tubing on the suction side to see if there are air bubbles going to the pump

Alternatively, start making it a practice, when you are approaching the problem scenario -
about to shut down after running -
try pumping the bulb then - don't wait until later when it won't start.

find out if the VST is pretty full - or already almost empty

and then, if later it still dies and now the VST IS empty.....!

[marchmadness]

I was thinking I might have an issue with the float in the vst . Maybe it’s not opening and not letting enough fuel in. What I don’t understand is why this only happens now . If I was having air leaks , in the same respect if you pressureize the system with the primer ball wouldn’t you have a gas leak. I have no start issues and I can’t find any air leaks.

[marchmadness]

Update on my fuel issue. Before taking anything apart I emptied the vst , there was around 7 oz . I removed the vst and replaced the needle float. The tank was clean and I don't think that was the problem. Next I checked my old friend the pressure relief valve, that was working ,not leaking and opened at around 10 psi . I did find two high pressure clamps that were not reel tight . also some possible other leaks. I will be putting it back together tomorrow and will follow up.

[oldmako69]

One of my 05 F225TURD's does the exact same thing. I've swapped the relief valves port to starboard and the problem did not follow.

The affected engine starts and runs like a chainsaw. Pull into a cove and toss the hook. Fire up the Cohiba and the tunes, open the cooler and relax. An hour later they both start right up. But when I throttle up to get up on plane, the starboard engine quits. Go back, squeeze bulb till firm. Fire it up and its back in chainsaw mode.

It makes sense to me that the fuel in the VST has done left the barn. What does not make sense is the engine is running at idle just fine. Why isn't this enough to refill the VST and prevent the engine from dying?

[marchmadness]

I thought maybe that the float was getting stuck or the float itself maybe filled with fuel. I guess at idle there is enough time to fill the vst back up. I have been chasing this every year. As rodbolt said its a dirt simple system but tough to pin down. The biggest issue I see is all the fittings, and clamps in the system that can fail. I emptied the vst but the motor had a chance to idle and it still wasn't completely full. I have been hoping for that ah ha moment but it hasn't come.

[rodbolt17]

you do not have a VST issue. you HAVE a fuel supply issue.
could be a valve,could be an anti siphon valve,could be a water separator head with corrosion. simply watch the engine filter cup at idle.

[marchmadness]

I put a short video . Rod bolt said to watch the cup at idle

[99yam40]

so without me watching a video, what are your thoughts on what you saw?