Yamaha 150 Four Stroke 2004

[dsinger]

The motor will not get up to WOT really just bogs down. Changed all the fuel filer even the one behind he intake manifold. Any suggestions. Also changed the gas. It wont get above 2500 RPMS will only just bog down. All the plugs look good all nice golden drown.

 

[JB]

Re: Yamaha 150 Four Stroke 2004

Service Manual?

 

[dsinger]

Re: Yamaha 150 Four Stroke 2004

Ya I have one.

 

[redbull660]

Re: Yamaha 150 Four Stroke 2004

I have a 2003 115 horse yamaha 4 stroke it did the same thing last year. Fuel tank sediment was getting to the injectors. I would take the injectors off and tap them on a clean white cloth and dirt would come out of them, I then sprayed them off with air and put them back in and boat would run great for a while and then back to the same thing. I also had the filter changed behind the intake. Here is what I found out after many trips to dealer.
On the factory fuel filter that is on the back of the engine, I found that the little filter itself had a seam in it that was not fully sewn together, it was allowing dirt to get by and go to my injecters. Since then I completely got rid of that filter and put in a 10 micron fuel/water seperator filter. No more problems.

 

[JUSTINTIME]

Re: Yamaha 150 Four Stroke 2004

sounds like u are in rpm reduction mode

get it plugging into the YDS program asap

 

[rodbolt]

Re: Yamaha 150 Four Stroke 2004

anything that triggers RPM reduction will also trigger audibleand visual alarms.
if the alarm system is working I would chase fuel
the F150 has 3 filters on the motor and one in each injector.
any of them clog and the motor wont go.
I got cleaning the VST on an F150 down to an hour, 15 min more and I can r&r the injectors too.

2 quick and simple fuel system tests,one is to check the railpressure, the other is to simply squirt fuel from a squirt can into the throttle body when it bogs.
if the railpressue is below spec, check both prefilters and the VST filter.if railpressure is ok and the engine picks upby spraying gas down the air horn.remove and clean the injectors.