getting worse, rpm & stalling

[tryc]

my 1997 yamaha 225 efi was dropping rpms at wot from 5500 to 4900 if i pulled back a little on throttle & open back up it will go back to 5500 for a few seconds & drop back down. i changed vst filter,engine fuel filter,10 mic.water sep.,all new fuel lines from tank to filter on motor inc. prime bulb &new fuel vent& hose. No luck. Tried running off 6 gallon tank still no change. Brought to yamaha dealer and they changed 02 sensor,spark plugs and adj. throttle body linkage. got boat back & 1st time out went wot for aprox. 90 seconds, seemed ok. cruised to fishing area and trolled for aprox. an hour, motor seemed to run rough during trolling. on way back in went wot after aprox. 20 seconds rpms dropped again.($930.00) later still have same problem. Bought another 10 mic. separator,when i dumped fuel from 1st separator into glass jar noticed a light tan fine sand like substance ? Next time out still dropping rpms at wot, and now when i was pulling into my slip stalled aprox. 10 times in a row. Back in sept. 07 i had a problem with stalling when trolling or pulling into slip. A different yamaha dealer then said it was clogged injectors and sent them out to Flagship inj. in FLA. when i picked up the boat they said the inj. where not real bad but my vst filter was really bad I am trying to find a fuel psi. gauge to fit the vst tank valve (metric). I was thinking it was a fuel pump problem but now that its stalling in gear at lowest rpm. and my vst filter is new im thinking my injectors ? Does Flagship only accept inj. from dealers? Any help would really be appreciated, THANKS.

 

[ARCHSEA BUNKER]

Re: getting worse, rpm & stalling

sounds like a bad fuel tank, my 2 cents, even running on a separate 6 gallon tank the crap is still in the system, clean vst filter and then try the 6 gallon tank also low pressur fuel pumps check, make sure your plugs are gapped to spec

 

[rodbolt]

Re: getting worse, rpm & stalling

doesnt matter if you replace every part of the engine fuel system this morning,if you add contaminated fuel at lunch you get to do it again at dinner.
fuel rail fitting is standard shrader fitting like a bike tube.
rail pressure has to maintain 33 to 37 PSI or it wont run properly.
we are seeing some nasty fuel issues here.
coats everything with a white powder and films over the VST and injector screens.
if your careful on the ox66 motors and work in a clean invironment you can carefully pop the filters out of the injectors and spray them out.

 

[snowmon]

Re: getting worse, rpm & stalling

damn e10 (if your lucky, probably more like e20 cause they add it at the local distributor). had all these problems when they switched in mass a few years back. my annual maintenance now includes new lift pumps, clean vst filter at least once a month, replace engine mounted fuel filter and keep an eye on all rubber fuel lines and related parts. alcohol kills rubber. also keep an eye on check valve at fuel tank pick-up. i finally pulled mine out of the link cause the check ball kept getting stuck closed.

 

[tryc]

Re: getting worse, rpm & stalling

Rodbolt,i want to try to remove my injectors and spray them out,do i remove the filter from it ,clean it ,then spray into the injector also? seems to be enough room to hopefully access injectors by moveing fuel rail over. I have a Snapon fuel psi. gauge, the fitting wont go on my vst tank stem. I tried it on my truck rim and it fit fine,so i took the chrome cap from that valvestem down to the boat and it fit fine???? After cleaning inj. i will hook onto a 6 gallon tank with fresh fuel and test run. Also when re installing inj. should i lube rubber seals with Yamalube tc3? or will they push in ok dry? Snowmon, i also am from Mass., have you seccessfully cleaned the injectors on your motor during time of your fuel problems? Thanks, any advice is appreciated,

 

[Home Cookin']

Re: getting worse, rpm & stalling

That "sand" in the system sounds like deteriorating fuel line liner, too.

 

[rodbolt]

Re: getting worse, rpm & stalling

I use my knife to pop out the filters.
one of my snap on fittings fit and the other does not.
go figgure.
same fitting number just one wont thread on far enough and leaks.

 

[tryc]

Re: getting worse, rpm & stalling

Thanks for all responses, Rodbolt, took half day from work today, removed injectors,tried to remove filters from inj. with fingernail and small screwdriver.Did not realize they were pressed in that tight. Not wanting to risk damageing them i held them upsidedown and sprayed them out,also removed vst filter that has only 2 or 3 hours on it and spray cleaned it. Next i hooked onto a 6 gal. port. tank and ran at the dock idleing and in gear up to 1600 rpm, seemed to run a lot better. weekend weather up here in Boston area is rain thru sunday afternoon. Next avail. chance i will bring more fresh fuel for 2 port.tanks and go for a ride,if its the fuel causeing the problem from my onboard tank, i have aprox. 100 gal. in it. Im thinking of makeing a rig with a pump hooked to a water sep. with a tighter than 10 mic. filter . connect to my tank feed & cycle thru to my fuel fill,(make a loop) and hopefully remove most of deposits.Then reconnect to on board tank. After this should i try to remove filters from inj.? Do they usualy pop out ok useing knife edge? If its still not running perfect,but better,could be some gunk got past inj. filters,if so the only inj. service for yamaha i know of is Flagship Inj. out of Fla. and i think they only deal with marine dealers? Thanks for all help, i am finnaly makeing progress.

 

[rodbolt]

Re: getting worse, rpm & stalling

most large cities in the US will have a facility that specializes in injector reconditioning.
nothing particularly special about that yamaha injector.
I use flagship cause if I UPS them out on monday I usually have them back thursday.

 

[tryc]

Re: getting worse, rpm & stalling

Got out for a short ride today,hooked to a 6 gal tank . Boat ran very well, no dropping rpms at wot or caughing or stalling when pulling into slip. Will try to cycle fuel thru tight filter and hopefully be able to use it up. After that, pull & clean inj. & vst. filter and replace engine filter again, add fresh fuel. Rodbolt, should i try to pop out inj. filters ? how often do they come out in one peice? Thanks (note : my fuel never looked real bad, no water, no heavy particles, as Rod bolt said its a nasty fuel issue, its a fine tan powdery, gritty substance causeing lots of problems. In a glass jar held up to sunlight fuel just looked cloudy)

 

[rodbolt]

Re: getting worse, rpm & stalling

are you nuts
if its running good on a shop tank DO NOT hook up the hull tank unless you really wish to spend some bucks.
give your fuel away to anyone, change the lines and clean the draw tube and pray.
dont make ma say dum bass.

 

[tryc]

Re: getting worse, rpm & stalling

Rodbolt, thanks for the warning, i thought that cycleing fuel thru a 2 micron filter a couple of times might get rid of the she ite. Most boats at our club buy fuel from the club,have talked to a couple of guys with fuel problems and 1 of them had same stuff in his tank (2 year old boat) we figure club got a bad delivery? first time any of us have seen this type of stuff or maybe E10 is doing its thing to our in ground tank(system was replaced aprox 12 years ago)Maybe older, carb. inboards can run this stuff? most boats haveing no issues, I will see if i can find any takers for my fuel. My buddys 2 year old Gradywhite with a 250 4 stroke yamaha uses same fuel and is running fine.

 

[Home Cookin']

Re: getting worse, rpm & stalling

Local mechanic told me that he spends all day every day rebuildnig carbs from bad gas from a certain boat club. The club claims it has an "acceptable" amount of water in the fuel it sells (and also told him to quit saying that). Althjough it would be more convenient to use the fuel docks, I'm hauling it to the boat in jugs.
I just think that fuel docks have to be more prone to water problems. The tanks are undeground near the water, hatches may go under in storm tides, and a long run down a pier (or underwater!) to the end of the dock.

So it might not just be one bad delivery but bad gas all around at your club.

PS I'm starting to have some problems despite my best efforts to baby my fuel. Oh well.