2004 yamaha 150 four stroke cuts off while running

[joddyjam]

Have 150 yamaha it will run fine sometimes 12-20 miles hard running then just cuts off like its out of fuel. Won't always crank back up. sometime runs fine pull back to idle runs awhile then cuts off. took to dealer for service changed oil filter,fuel filters,new water pump kits ect. dealer said he checked fuel press. (ok)checked high press pump seemed to work fine. took boat out ran for about 24 miles no issue.next day went about 8 miles engine quits won't restart. wait until next day ran for awhile then starts same thing again. ANY IDEAS ON WHAT IS GOING ON?????? RUNS FINE AT DEALERSHIP!! NOTE: HAVE TWIN 150s left engine no problems. right engine has problem!!

[TownsendsFJR1300]

Next time the issue happens, pull the engine cowl and see if there's fuel in the Yamaha, clear plastic filter.


Something as well to check;

On my 06 F150, the ethonol fuel swelled the under cowl, clear Yamaha filter cup. When I tighten it down, and it was tight, the cup itself DID NOT SEAT on the o-ring and eventually "ran out of fuel(with a full tank). I ran the boat 15 miles offshore to a reef and back and several other trips with no problems running (with that cup NOT on fully) before it eventually acted up. That cup should slide into the mount easily and seat on the o-ring upside there..

I had it replaced under warranty once and just replaced it again about two months ago as it was starting to swell.

[rodbolt17]

that engine filter cup wont stay full during normal operation, it tends to stay about 1/2 full as its on the suction side.
if the cup swells typically we can lay it on the bench overnight and it will fit again.
when you say it wont start, will it crank over or not crank at all?

[joddyjam]

engine always turns over just wont start!

[rodbolt17]

when it cuts off, does the fuel pump run when you turn the key off wait 10 sec and turn it back on?
loss of the main relay,relay operating voltage or relay ground will do just that.

[joddyjam]

found the problem: it cut off,would turn over but would not start. decided to check the harness in engine pulled it apart had corrision at some of the pins tried to clean them,but they were too bad.So i cut harness spliced wires & heat shrink them, motor fired right up has not quit since. called my dealer he is ordering me new harnesses. i have ran about 50 miles since with no issues. THANKS FOR EVERYONES HELP!!!!!!!!!!