F225 Requires Multiple Starts

[MealsOnReels]

I need to lean on you again for a little advice re: my 2003 F225TXRB 69J X 1003602 Q (Canada). It’s an EFI with 209 hours. Fresh water only. It is unlikely I will tackle a repair myself unless it is very straight-forward. I do not have the tools (e.g. software) to check things out in detail.

My objective is a little education before I see my local Yamaha dealer. If you feel this has been described in detail on this forum - please point me to that place. Or you might suggest that I go straight to my dealer which I am OK with.

Recently the engine is -sometimes- hard to start. Rarely it starts on the first try. Often it takes maybe 4-8 “tries” to get it going. What I mean by “tries” - I start the engine, it runs for maybe 2 seconds and stops. I do this over and over until it starts and keeps running. Pumping the primer bulb makes no difference in my experience.

My basic config is Gas tank -> Racor secondary filter -> Primer bulb -> Yamaha Primary filter.

Possibly related: Once this year after running for about 10 minutes at idle in gear heading out, the engine started to shake and it stalled. I could not restart it. Of course it was in a busy channel. So I just threw out the hook and began to investigate. I noticed the primer bulb was hard as a rock, which it never is. The fuel line appeared slightly kinked at the bulb which I straightened. I sat for maybe 15 minutes and investigated again. The primer bulb was now soft. I tried the engine - started right up. No problems like this since.

I have now read various threads related to the VST and lift pumps. One thread seems really close, but owner only has a problem on first start. Mine has nothing to do with first (cold) or subsequent (hot) starts. I now understand it might be air in the line on the suction side, lift pump or maybe a sensor.

My Action Plan: 1. Replace Primer Bulb. 2. Check for air leaks on suction side (inspect hoses, primer bulb). 3. Check primary fuel filter at startup (is it going dry?). 4. Add a piece of clear tubing before the lift pump as described elsewhere on this forum to check for air bubbles (is clear metric tubing going to be a challenge?) 4. Stick a fork in me.

Thanks in advance for your feedback.
Robin

[panasonic]

I do not pretend to know these big engines at all. But your trouble shooting plan seems sound to me. Try what you said and see what happens. Your time is a lot cheaper then the dealers...maybe. I am am sure you will learn something from working on your own engine.

The other gentlemen on here will help you along...

[99yam40]

I would start out monitoring fuel pressures to see if they are a problem before doing anything.
then see if pumps run when they should

[fairdeal]

I would start out monitoring fuel pressures to see if they are a problem before doing anything.
then see if pumps run when they should

a good approach IMO.

Robin - your engine is not directly running off the fuel in the boat tank.
It has its own built-in miniature fuel tank - the VST
inside there, is the electric "high pressure" pump which supplies the injectors

When you "pump the bulb until it is hard" - you are filling that VST to its max

the VST normally holds about 250 mL of fuel -
enough for the engine to start immediately and then idle for at least 5 minutes

Whenever you turn the key on - not turning it further to run the starter -
the pump in the VST should run for about 3 seconds and then stop
- a faint pleasant whirring sound -
can you consistently hear it? helps to have the cowling off

[rodbolt17]

go with option 4.
it will be cheaper.

[MealsOnReels]

F225 Requires Multiple Starts

Thanks to all for explanations and tips. My last boat had a Volvo 425HP diesel which I found relatively easy (and expensive!!) to work on. The Yammy is definitely over my head in many ways but I can do the simple stuff.

I will update the forum in a few days with my findings. Robin

[rodbolt17]

that yammie is way easier and cheaper to work on than that Volvo.

the Yamaha uses a dirt simple speed density open loop EFI system.
do a tad o google and you can understand how and why each part is there.
TPS, gives throttle opening.
MAP gives barometric pressure and intake manifold pressure.
intake air temp gives an indication of air (oxygen) density.
coolent temp tell how warm the engine is.

all this information is fed to a truth table.
also called an ECU or control unit.
based on inputs the outputs control injector on time, fuel pump running.
spark timing.
injection timing. and so on.

it is actually simple.

[MealsOnReels]

Update: F225 Requires Multiple Starts

After 3 days of numerous starts it appears my multiple-starts situation has dramatically improved. I’ve just done two things. First I carefully inspected my fuel lines external to the Yammy including the primer bulb for cracks / possible air leaks. No issues found. Second, per forum suggestions including the primer bulb youtube video, I arranged my primer bulb such that the arrow on the bulb is now vertical (pointing up). Previously the primer bulb laid flat in the motor well.

I am pleased to say that over the last 3 days and numerous starts there has been only one time (a cold start) where the Yammy required two starts to continue running. Otherwise my Yamaha now runs on first start.

I am very thankful for the advice that I received from all of you.

I defer to the experts for better explanations but here is my rough guess for comments.

Guess: My Yammy required multiple starts because the VST was not being adequately filled prior to turning the key to “start”. My primer bulb was a contributor to the problem but possibly not the whole story. I reckon the check valve in my primer bulb is weak. Raising the bulb to vertical mitigates this specific problem. I will replace the defective bulb with a high-quality bulb and I will keep the mount vertical.

While I am happy that this seems to be a very simple fix I realize that there may be other fuel system issues. As suggested further testing (e.g. pressure testing) would help answer any questions. Thanks - Fairdeal and 99yam40.

RodBolt: Re: Simplicity of Diesels versus Outboards
Thanks for your explanation of “principles of operation” for my Yamaha - very helpful. My Volvo diesel had no electrical system to speak of other than a primitive computer that logged fault codes. This simplified things for me. In my experience if I had any trouble it was related to fuel, air or raw water, which I found simple to trace. That said I completely agree that things like turbo chargers and heat exchangers can be complex and extremely expensive to repair. For sure I don’t miss changing the six gallons of oil and 12 gallons of coolant or the impeller that was the size of a five pin bowling ball.
Robin

[fairdeal]

I'm very glad to read that your situation has improved

But FWIW, "looking askance" at the theory behind it.

Orientation of the primer bulb can be significant if you are trying to use it to pump fuel

But unless you have drained the VST, there is no need to use it - or any need, or use, for it.

Under routine circumstances it is just a piece of rubber that the fuel passes through.

You don't need its check valves except when you are actively squeezing it.

Absent a defect in your fuel system - an air leak- the fuel will no more "run back to the tank" than liquid will run out of a soda straw when you have your finger over the top.

And even if it did - it couldn't empty the VST - and that holds plenty of fuel to start the engine and run until the lift pump refills it

[MealsOnReels]

F225 Requires Multiple Starts

Thanks again fairdeal. Your reasoning is why I said "possibly not the whole story".

So next steps will be to first install the new primer bulb, then install that clear tubing to check for air leaks. Seems straightforward assuming I can obtain the correct-size tubing.

Question. Your last comment strongly implies there is no way for fuel to back-flow out of the VST. It sounds like the VST has to be manually drained. Since fuel can be pumped into the VST with the primer bulb, what mechanism (e.g. check valve) prevents back-flow?

I take it from your comments that the VST should almost never run dry, once it is primed with the bulb (like for me, first-time in spring).

Per your previous note - Can I hear the VST pump running when I turn the key to "on"? The answer so far is "no" but I have not removed the cowling thus far. So that is another outstanding task that I have.
Robin

[boscoe99]

Fuel flows into the VST from the top. There is a drain line but a valve has to be opened to allow fuel to flow out. For servicing purposes only. There is no way for gasoline to backflow out of the VST via the fill line.

In an EFI model there is almost never a need to even touch the primer ball. As noted, fuel will remain in the VST at shut down. Enough fuel remains in there to start the motor which then gets the lift pump going. The lift pump will keep the VST supplied with all of the fuel it needs.

The HP pump is quiet. You might have to put your hand on the VST to see if you can feel the pump run for about three seconds when the key is turned on.

[MealsOnReels]

F225 Requires Multiple Starts

The diagram and explanation is most helpful. Thanks!

As you know my Yamaha is an EFI. The way the bulb has been exposed in the motor well looks to me like a bit of a hack. I speculate the previous owner may have had starting issues and took some action to install the bulb in a convenient location when in fact there is some other issue.

My understanding from your note: When the key is turned on, the high pressure pump in the VST is activated to fill the VST as necessary. Once the engine starts the low pressure pump (a.k.a. lift pump) supplies necessary fuel pressure for all running RPMs. Am I correct?
Robin

[boscoe99]

The diagram and explanation is most helpful. Thanks!

As you know my Yamaha is an EFI. The way the bulb has been exposed in the motor well looks to me like a bit of a hack. I speculate the previous owner may have had starting issues and took some action to install the bulb in a convenient location when in fact there is some other issue.

My understanding from your note: When the key is turned on, the high pressure pump in the VST is activated to fill the VST as necessary. Once the engine starts the low pressure pump (a.k.a. lift pump) supplies necessary fuel pressure for all running RPMs. Am I correct?
Robin

No. The high pressure pump in the VST is activated to pressurize the fuel injector rails. That pump will only run for several seconds when the key is turned on. It will then turn off.

When the motor is being cranked the VST HP pump will start running. Once the motor is running the VST HP pump will continue to run. Constantly.

The low pressure lift pump refills the VST. It will only run once the motor is running. Below 1200 it will run for 10 seconds out of every 30 seconds. It rests for the other 20 seconds out of every 30 seconds. It does this because not much gasoline is needed when the motor is running at low RPM. Above 1200 RPM the low pressure lift pump will run continuously.

[oldmako69]

(1) ......But unless you have drained the VST, there is no need to use it - or any need, or use, for it.

(2) ....Absent a defect in your fuel system - an air leak- the fuel will no more "run back to the tank" than liquid will run out of a soda straw when you have your finger over the top.

And even if it did - it couldn't empty the VST - and that holds plenty of fuel to start the engine and run until the lift pump refills it

Sorry to hi-jack the thread, but these comments are germane to my last remaining F225 issue.

Namely, after I shut down the engine and drift or anchor up, say I just sit for an hour, the engine will always start and will idle nice and smooth. BUT, when I then throttle up-giddy up, the engine will bog down and quit. IF I squeeze the bulb PRIOR to starting it will run properly.

So, clearly my gas is going somewhere or my lift pump is not refilling the VST after start. Yet, when I watch the first stage filter I can see it being refilled, and I have gone over every inch of fuel hose, clamps etc and I can't find any anomalies. I am going to swap lines TO the engine from the Racors. Hopefully the issue will follow and enable me to fix it. I clearly suck at wrenching as I have already gone through the fuel delivery - tank to Racor and Racor to engines - yet the problem persists.

***The engines run about 90 percent better than when I bought the boat and they do so 98 percent of the time. I am making progress, but I still have this last remaining issue.

[panasonic]

I had some oil spill on my transom. It came from my middle f225. At first I thought it was a failed speedy sleeve, but I recalled I checked the oil on the dipstick 5 days ago, and added oil as I thought it was down a quart.

Could I have added too much oil?

i had an oil spill once before on a different engine, but can't recall what the issue was.

Anyone have any answers?

Start a new thread...I am sure you will get lots of responses from the members here...