F 115 TXRB intermittent issue

[deanpijut1967]

Hello,

The engine starts and idles fine. I slowly get out of the marina about 3 to 4 mph. Then when i hit the open water and put the throttle to wide open the engine accelerates and then the rpms drop to zero and then back up surging up and down. After a short period of this then the engine is fine the rest of the time out on the water. I can start, stop, ***** or go wide open with no issues. I have no Yamaha dealer close by. Unfortunately i had a mechanic splatter gun repairs and put on everything but the kitchen sink. Before the mechanic left town he mentioned that the spark looked weak. Could a coil be opening after sitting out of the water and then after engine heat up it provides a better spark? The problem goes away after the first 15 to 20 minutes of engine running. Also no codes on yds software.Before i have to schedule a vacation and take a road trip about 250 miles one way to closest certified dealer i would like any input if anyone has had this issue.

All fuel system cleaned and serviced.
new high and low pressure pumps and grommet.
Fuel lines and vst filter and primer ball.
new injectors and pressure relief valve.
t stat and temp sensor.
tps and iac sensors.
new plugs
main relay and both engine harness.
main engine harness and key switch.
ecm.

Thanks in advance.

[rodbolt17]

try pumping the primer bulb just before ya whack the throttle to WOT.
if it helps or clears the issue find out why the VST fuel level is low.

if the fuel level in the VST is low and you hit the throttle hard,thats just about what happens.

[deanpijut1967]

you were correct. I pumped the primmer ball and hit full throttle. It stumbled for a brief second. Then ran great.

What could cause the fuel level in the vst to become low after sitting for a week or two?

Thanks again for your assistance.