F225 2004 engine quits and bogs down at 3500RPM

I have a 2004 Yamaha F225TXRC. There are 330 hours on the engine. After spending $3500 at a Cocoa, Fl. place, my issue remains the same. I'm not the type to return to the scene of a crime, or if a Dr. cut off my left arm instead of left leg. Why would you expect better results? Cooler now, I'll work it.

Symptoms: I used the boat infrequently, mostly run the engine monthly. The fuel tank was drained and cleaned. The engine ran well at idle at the dock for a time, now it will struggle and die. My son noticed that the fuel filter bowl in the engine drops below the filter element about half way down the bowl just before it dies. I can turn the key off and it will restart and run immediately. When it first starts to struggle, pumping the fuel primer bulb helps.

Actions: The shop did a full annual service. Injectors were removed and ultrasonic cleaned, one was replaced with a new Yamaha injector. Plugs are new (I did that) and good. Removed the VST and cleaned it. The fuel pumps were tested on the bench. They did run the boat on open water tests using a gas can direct to the engine. During the open water test, the engine bogged down at 3500 RPM. Fuel pressure fluctuated, drops to 35PSI under load. High pressure fuel pump was replaced and the VST, screens cleaned.

The fuel filter is new. It has a bowl and drained several oz. and it was clear. New fuel is non-ethanol. I do have a Yamaha fuel flow sending unit installed just after the fuel filter. I removed it, I'm wondering now if the paddle wheel is sticking. That could account for the sudden stall after traveling 1/2 mile but not the 3500 RPM limit. Haven't tested it yet. I also noted when the engine wants to die, pushing up the throttle up only worsens the situation.

Any insight would be appreciated.

Also, any experience with the diagnostic sets (pigtail and SW) available from E-bay vendors? Seems they are all out of the country.

I need to provide more info.
The maintenance log states that it was run on a separate tank. I also ran it on a portable tank of fresh fuel, same problem but the heat here in August convinced me to throw in the towel and let the pro's do it.
The fuel tank was drained (90 gal) and cleaned. Issue is the fuel sending unit does not seem to be disturbed. How else would it be "cleaned" if not through that hole?
Starting and running the motor at idle is not an issue, unless it decides to quit after a few or 15-20 minutes or whenever. I made a quick attempt at full throttle in a "slow speed" zone and felt it bog down. Didn't continue.
The high pressure pump was replaced. The VST was cleaned twice to include any screens to include VST and all injectors. I do not see a reference where the low pressure pump was replaced. I read somewhere that O'Riley's auto stores has a low pressure pump that can be used with little modification.
All of the electrical connectors were inspected and reconnected.
I removed the Fuel Management sending unit from the fuel feed, wondering if the vane is sticking. Engine started well, ran at the lift with RPM raging from idle to 1200RPM increasing the RPMs and letting it run at that speed. No open water trial.

Keep us posted after open water trial. Definitely sounds like a fuel restriction or weak low pressure fuel pump issue.

johnnygjr said:

Keep us posted after open water trial. Definitely sounds like a fuel restriction or weak low pressure fuel pump issue.

Click to expand...

Gentlemen you are Super!
I did remove the fuel management sender Saturday, and this morning I went and made sure all of the fuel hose clamps were centered on the barb and firm/tight. The one at the input side of the primer bulb was secure, clamp would not move but not tight. Took care of them all and my son, son-in-law took it out for a trial.
No stalling and no hesitation after a 4.5 mile put-put looking for speed bumps.
Got into the River and let it rip. Slowly increased to 5000 RPMs and 32 mph. Increased to near 6000 RPM but only for a minute. We went out with the cowling removed and I'm deaf now, but a good deaf.


Getting back to the dock, I did hear the relays reset so no issue there.


The primer bulb is a generic (Atwood?). It's behaving itself now, but I may buy a Yamaha one. I had 2 in the past and the failure point was obvious when they suddenly went rock hard.


I have one last question. Do these shops have their techs working on commission? Reason why I ask. I found my old car shop did but after they wanted to replace my complete AC on a 1999 Dodge truck for $950. Told him to close the hood. The AC has been working for 2 years now after tapping the clutch.


So, lesson learned: come to you guys and discuss before considering a marine shop.


Thanks again!

Thanks for the update, A lot of threads never get back to the forum with results,good to hear your running

johnnygjr said:

Thanks for the update, A lot of threads never get back to the forum with results,good to hear your running

Click to expand...

Feedback is very important. You never know where you are until someone tells you.

I read this thread with interest as I have a pair of 05 F225 Yam's on my boat. One of them is acting up in a similar fashion to yours and I have yet to get to the bottom of the problem.

I saw a reference to a pump from Oreilly's. Here are two pumps advertised on ebay. The low pressure pump (the one located outside the VST) from Yamaha is over 400 bucks.

These are a fraction of the price. I bought one just for grins. I have yet to install it. Anyone else have any luck with this Yam issue? I have already replaced the bulbs, trimmed all the fuel lines, new clamps, all new filters, pulled and cleaned the VST, etc.



http://www.ebay.com/itm/291393695827?_trksid=p2060353.m1438.l2649&ssPageName=STRK:MEBIDX:IT


http://www.ebay.com/itm/152174305353?_trksid=p2060353.m1438.l2649&ssPageName=STRK:MEBIDX:IT