2004 Yamaha F225 TXRC Stalling

[silverknife]

It Started last season when my starboard 600 hour F225 TXRC Yamaha 4 stroke engine died on my last outing of the season. The engines are on a Grady-White 282 Sailfish. Boat was pulled for the season and the marina mechanic said LP fuel pump fuse was corroded and had blown. (???!!) He insisted everything else was fine. Fuse replaced-$15.00

Boat was splashed in May. On my first day out the starboard engine would not maintain RPM, ran very rough, and then stalled. Would not start again withot priming it. Marina pulled the boat. Diagnosis=Injectors are plugged from deteriorating fuel lines from the fuel tanks to the engine, BUT all of the filters before the low pressure pump were clean and the port engine was running just fine. Pulled the injectors on both engines, had them cleaned. The shop in FL said that 4 of the 6 injectors on the starboard engine were clogged but the port engine injectors were like new. I replaced every filter on both engines including the HP Pump in the VST and replaced all fuel lines and primer bulbs from the tanks to the engines. $2800. Mechanic said it was all good -go have some fun!

Took the boat out, the starboard engine kept stalling and would not restart without priming. Returned to base. Called a different mechanic.

When the new mechanic started trouble shooting, the engine would not start even after priming. We found that the LP pump was barely pumping fuel and the fuel that it was pumping was contaminated with black crud. The fuel was crystal clear before it entered the pump and the fuel in the port engine was likewise crystal clear. We ordered a new LP pump from Yamaha ($550). I took the old LP pump home and opened it up. several of the contacts at the top of the armature were missing and/or broken and both of the brushes were chewed up. Obviously that was the cause of the blown fuse and clogged injectors. There was nothing wrong with the fuel lines!

When the new pump arrived we installed it and prepared for a good time with the rest of the season ahead. NOT SO FAST! The starboard engine kept stalling!

Went back into the engine. Found that when the marina mechanic, replaced the filter on the HP pump in the VST he pinched and tore the O-ring on the top of the VST cover. AHA! The engine was sucking air! Ordered a new O-ring from Yamaha. Got the O-ring installed it, got ready for an enjoyable boating season ahead. Took the boat out, the starboard engine kept stalling.

Reversed the fuel lines so that the line that fed the starboard engine now fed the port engine and vice versa. Checked ALL of the connections and fuel lines in the engine. Everything was tight. The starboard engine still stalls.

The fuel that I use has NO ethanol and I have ALWAYS add Yamaha fuel additives every time I refuel. I operate in fresh water only.

Anybody have any good ideas?

 

[99yam40]

Maybe the injectors caught more of the junk from the bad pump.

Have the techs monitored the fuel pressures when it is having problems?

Pressures will not show injector problems, but will show pump, air leaks, and filter/restriction problems

When is this motor stalling? idling, high speed?

 

[silverknife]

Thank you for trying to help me sort this out.

The motor stalls at idle. After the o-ring on the VST was replaced yesterday I cleaned up the boat to go out again. (The spiders made a mess of it in 10 days of no attention). While I did that I idled both engines for about an hour and a half, the engine stalled just before I cast off. I left the dock anyway, but even after priming the engine it would not run long enough to get out of the marina and up to speed so I did a 180 and moored up again. After the new LP pump was installed the fuel pressures were fine but I am wondering whether the new LP pump failed. Stranger things have happened. I think that pulling the injectors is probably a very good idea. Thank you. I was out for a while on the bad LP pump after the marina replaced the cleaned injectors. I suppose they could have clogged up again. Question: Does that scenario make sense in light of the fact that when cold the engine was able to idle for almost 90 minutes?

 

[Capt Ken]

First, the pinched O ring will not cause stalling. It just seals the tank to keep fuel from leaking out when tilted. But you need to find a mechanic with the new YDIS test system. He can both plug into the engine's computer plus be able to monitor the fuel pressure via the laptop. Otherwise you are spinning your wheels. If your mechanic doesn't have the equipment, find one that does. The new system is only issued to authorized dealerships.

 

[silverknife]

CAPT-There are two Yamaha dealers in my area. One FUBARED the diagnosis last year, telling me the LP pump was fine when it was destroyed. Then the same dealer sold me the R&R of all the onboard fuel lines that were perfectly good AND suggested that I replace the injectors instead of sending them out for cleaning ($2400 parts vs $600 service). After he did the $2800 service he told me that all was well when the LP pump was pumping very little fuel which was contaminated with the broken armature contacts and destroyed brushes. He's also the dealer/mechanic who pinched and tore the O-ring in the VST. The other dealer wants to work on the boat only at his shop but has no trailer and neither do I (or a vehicle big enough to haul the boat). I am between the proverbial rock and hard place on authorized Yamaha dealers.

 

[99yam40]

If cleaning up the fuel system from the low pressure pump to and including the injectors
again does not help then you will have to find someone with a trailer to transport the boat for you.

I would have been all over the other shop about the $2800 after finding the pump bad