2004 Yamaha LF225TXRC cuts out after 4500 RPMS

[cobia1984]

Our 2004 LF225TXRC outboard cuts out after 4500 rpms. The other motor is running fine.

We hooked it to YDS software and with motor off and out of gear in neutral it says it can no execute a high pressure fuel pump test because the motor is in gear.

Does this sound like a faulty neutral switch or throttle position sensor.

Thanks all appreciate any thoughts on both of these issues.

Thanks.

[bajakeith]

OHH Myyyyy

Not a TPS issue for sure...

[rodbolt17]

possibly a TPS issue.

why not simply look at the tps voltage with key on engine off???

better yet do a bit of reading on WHY you even hooked up YDS to start with.

if the TPS voltage is abnormal it may prevent certain static tests to work.

but the TPS most likely isn't the shut off issue.

[cobia1984]

Thanks for the reply.

These are the codes that come up.

18 Throttle position sensor 221
29 Intake press sensor 272.8

Engine has 292 hours now.

When I ran the boat again it still will not go above 4500 rpms. Anything over 4500 it cuts out.

I have read tons of post saying it is either in the VST tank, clogged injectors, or the shift cut off switch.

I watched the shift cut off switches on both motors while my dad worked the shifters. The starboard motor only pushes metal lever on the shift cut off switch when you go from reverese to neutral does not activate switch going from forward to netural.

The port motor the one I am having an issue with the cut off switch is activated only when the motor is taking from being in gear forward to neutral not from reverse to neutral.

[rodbolt17]

you most likely have a fuel issue.
the ECU wont react to a shift cut signal at that speed,

hook up the YDS,run it till it cuts out, hit save and it will show the last 13 min or so of data.

clear any stored codes first.

[Nautical]

Fuel Injector..clean/replace.. Takes a few minutes to pop em and clean em..

[cobia1984]

Thanks for all the tips greatly appreciate it. Going to clean the injectors this weekend.

Going to get some BG injector cleaner and ill set up a syringe and power supply to clean them that way.

I have a variable DC power supply from 1 volt up.

Looks like those injectors will open at 1.5 to 3 volts is that correct or is their a better voltage to set my supply at?

Going to clean the VST tank and replace VST filter while I am doing injectors as well.

Again thank you.

[99yam40]

pay attention to Rodbolts reply's,
as he if the only one that has posted he is a Yamaha master Tech

[cobia1984]

Thanks rod bolt. Will run Saturday and hook up YDS going to hook fuel pressure gauge up while running. Am I correct from what I seen 32 psi min on high pressure but should have about 35 or 36.

[Offshore_life]

I had the same issue on my ox66 . Would cut out at 4500 rpm . Turn out to be a bad LP fuel pump torn dipham . I'm not sure if your motor have LP fuel pump .