03 150HP 4 Stroke bogs when throttling up

[dustin0479]

Hi. I have a 2003 150 4 stroke with only 117 hours on it. The motor starts with 2-3 turns and idles smooth. When transitioning from Idle to throttle (around 1000 rpm) it bogs down badly (to the point it sometimes dies) but after it catches up an the "surge" it is perfectly smooth again. Fuel stabilizer was added to the tank when it was winterized last year and all the normal service was done.

Any suggestions?

[99yam40]

Rodbolt17 has posted on this in the past, here is one but there are more in dept posts out there on the fix

http://www.yamahaoutboardparts.com/f...g-th16933.html

Finally found it, here is the one I was thinking of
http://www.yamahaoutboardparts.com/f...0-th15195.html

[dustin0479]

I read all 14 pages worth an honestly can not tell what he did to fix it... I am not exactly an Outboard guru. I have someone looking at it tomorrow but I do not want to go through 5 months of part changing to figure it out....

[99yam40]

I believe he had a bad map sensor, it should have been found just by looking at diagnostic info, The barometric reading at key on did not match up properly, but the ones doing the troubleshooting did not look at it well enough
but what I was getting at was Rods way of adjusting things to fool ECU a little. He is a Yamaha master tech and he knows his stuff. He even has a F150 his self.

[rodbolt17]

after you do all the maint, then fake out the ISC.
at the end of the day your looking for a smooth idle,about 40-45% isc command and a smooth throttle up.
this cannot be obtained with a service manual.
my personnel F150 did this out of the box.
took me about a half a day of playing to make it quit back in 07.
now it takes me about 15 minutes.

[dustin0479]

I gave the info to the tech looking at it today. I may have botched the description up though.

The first tech I spoke with told me it sounded like the high pressure pump. I asked him what the HP pump did and he explained. I am not an outboard guru but I am pretty sure that is not the problem, this is what I am working with.....