F225 surges and misses over 4000 rpm

[swimdad]

I have twin 2003 F225's with 200 hours and I think one is possessed. It will run fine to 3800, you can baby it up to 4000-4100 but anymore else and it will drop to 3200 or so and surge back and forth. We have replaced EVERY filter had injectors rebuilt and certified, had the VST cleaned 3x, plugs replaced and most recently the main fuel pump replaced. We have tried pumping the bulb while running around the 4100 rpm cutoff and no difference. No codes are showing up on the yamaha software.

We are on mechanic #3, 2 of whom are Factory certified, and I have spent several thousand $ am paying guys $100+ an hour to "try and figure out whats wrong" for several hours or days at a time with no results.

Any thoughts, ideas or name of a mechanic in the Galveston, Houston area who will guarantee their work would be much appreciated.

 

[drchpete]

Re: F225 surges and misses over 4000 rpm

Don't know why it does this but I have a 2000 Yamaha 40 2-stroke that does the exact same thing. Hope someone can clue us in.

 

[rodbolt]

Re: F225 surges and misses over 4000 rpm

the 40 2 stroke is a complete different animal.
on the F225.
what is the fuel rail pressure AT the problem RPM AND load?
what is the barometric pressure on the laptop at key on power?
what is the TPS voltage at the problem RPM AND load?
no codes set simply means the ECU is happy with all the sensor inputs, thats all it means.
use the yamaha dealer loacator function, use it to find a dealer near you that has a yamaha master technician.
your issue should have been found and resolved in the first hour of testing.

 

[swimdad]

Re: F225 surges and misses over 4000 rpm

Thanks Rodbolt for the feedback. I used Yamaha's dealer locator and there isn't a Master technician anywhere within a 100 miles! The surprising part is I live in Houston and the boat is in Galveston. I found a "boat technician" one of which already worked on it (mechanic # 3) and 2 "factory trained outboard technicians" once again one of which who worked on it (Mechanic # 1)

Being able to diagnose the problem in an hour sure seems reasonable, providing the person really knows what they are doing. I think a lot of mechanics are more interested in switching parts and running up a labor bill. I am going to try the last "factory trained outboard" mechanic, but under the pretense that he can accurately diagnose the problem in an hour or less.


thanks

 

[jeffersondodson561]

Re: F225 surges and misses over 4000 rpm

Have they looked at a shift interupt malufunction? Take the switch out and check continuity open and closed. Closed (depressed) 1-3 ohms, Open (not depressed) OUCH or OL

 

[rodbolt]

Re: F225 surges and misses over 4000 rpm

switch interrupt is ignored by the ECU above about 3000 RPM.
why test something the ECU monitors?
its just to simple to look at the laptop data, figure out what its telling you.
if all is good then look at what is NOT monitored.
things like injector screens clogged,low rail pressues or a dead spark plug.\
the test wheel YB1626 can be used on that engine even though yamaha doesnt specify it.
makes static trailer testing easier.
that engine can be run with the airbox off while spraying fuel down the intakes at the problem RPM and load.

 

[jeffersondodson561]

Re: F225 surges and misses over 4000 rpm

Have they verified that cam timing is correct, belt skipped a tooth, never seen it but heard it can happen especially if the flywheel is rotated counterclockwise.

 

[rodbolt]

Re: F225 surges and misses over 4000 rpm

simply cannot skip a tooth.
can be verified easily but it would affect the engine at all RPM ranges.
if it skips a tooth something broke.
what your describing is typically a fuel issue.

 

[jeffersondodson561]

Re: F225 surges and misses over 4000 rpm

Never say never in this business if they have replaced every filter(?) on principle or did they have reason to replace every filter because if debris can get past the inline filter, fuel pump filter and all the way up to the injector filters something is going to have to be replaced i.e. fuel pump. What are the sea trial results and why have they not experienced these problems underway?

 

[rodbolt]

Re: F225 surges and misses over 4000 rpm

apperently you dont have much experience with gilmer tooth type belts.
if the skip it means something broke and it simply keeps skipping. the f200 AND f225 motors are clearence type engines, means the valves and pistons can clear each other in the event of a belt failure, have never seen a failure yet.
a stuck TPS can and will cause this symtom but its also usually accompanied by stalling at idle.
ever seen an F225 run with the cam off time?
wont make 4000 at all and wont idle well at all.
next time its on the laptop have them check barometric pressure with key on engine off.
it can fail in range and not throw a code yet the engine wont run correctly.

 

[jeffersondodson561]

Re: F225 surges and misses over 4000 rpm

Well is sounds like everyone who works on this engine is glory seeking. Usally when customers have brought their boats in that have been through so much headache usally describe that more than the symptoms they are experiencing, it might be time to go back to the basics. I noticed that no one has said they have checked thd condition of the batteries or the battery cables. It might be time to go back to the begining. Still baffles me that they would have you clean all of the injectors when they could have done a fuel pressure drop test and seen the varience of the injectors among the others.

 

[rodbolt]

Re: F225 surges and misses over 4000 rpm

because the yamaha software doesnt have that function.
a few programs do have that function just none that fit the yamaha.
what usually happens is untrained techs or techs that have completed outboard systems get intimidated by all the wires and shiney parts and leap to conclusions.
if it was a low voltage due to a bad cable that wil show up on the yamaha software.
if it was a TPS stuck that wil too.
however it says no codes.
there are a few in range sensor failures that can bite you but if the tech is trained and knows how each engine subsystem affects the rest its easy to spot.
and thats the problem on the net sometimes.
we are not looking at it.
we have no way of knowing if the regulator/driver update was done,the throttle bushing update nor the link rod update.
but all tests have to be conducted at the problem RPM and load.
thats where the dyno or the YB1626 test whel comes in handy.
sometimes though I simply have to crawl out on the braket and take a flying ride listening to it scream with the hood off.
cleaning out the VST on the F200/225 takes me about 2 hours 2 and 1/2 if I go ahead and swap the injectors with ones already reworked,cleaned and tested by flagship.
we keep 3 sets in stock.
its typically a judgement call based on the amount of debris in the VST and 30 years of experience.
stbd side injectors take about 15 min port side about 2.5 hours.
so at 4200 RPM with 38 PSI on the rail, no codes no inrange failures then your typically looking at a lack of fuel in a cylinder for whatever reason.
or a simple dead spark plug, easily found with your Kv tester.

 

[jeffersondodson561]

Re: F225 surges and misses over 4000 rpm

I have used it many times it is under stationary test.

 

[jeffersondodson561]

Re: F225 surges and misses over 4000 rpm

Have they checked on service bulletin O2003-017?

 

[rodbolt]

Re: F225 surges and misses over 4000 rpm

no IT IS NOT.
the injector fire test simply tests the ability of the injector to fire.
it is NOT a balance test.
it doesnt even use the same circuits that the engine operates on.
to properly use a test for injector balance it requires a known start pressure and a known injector on time duration and a good rail pressure tester.
if you turn the high pressure pump on during the test it makes any pressure reading meaningless.
how many Yamaha courses and actual experience do you have.
MMI and yamaha outboard systems ?
and there are 3 tech bullitens that potentially affect an F200/225 in 2003.

 

[jeffersondodson561]

Re: F225 surges and misses over 4000 rpm

Well if you say so, but when checking injectors I have always pressurized the rail (disconnceted the fuel pump and repeated) operated the software to statically operate the injector and watched the fuel pressure drop to the coresponding cylinders, if they all dropped equal amounts the injectors are good. In stationary test mode the pulse width is the same for each injector so each injector will drop pressure equally unless faulty. I would never have the injectors cleaned on a hunch.

 

[jeffersondodson561]

Re: F225 surges and misses over 4000 rpm

QUOTE=rodbolt;3001522] and there are 3 tech bullitens that potentially affect an F200/225 in 2003.[/QUOTE]