help! 2000 200hp yamaha stalling

hope you'all can help me out!
My 2000 sws 200hp yamaha has run great for 6 years--always maintained.
last month, while running in from 30 miles, she just died. I waited a couple of minutes, re-started and ran in another 10 miles before it did it again.

I dumped the watr-fuel sep and ran fine for a couple more weeks---then this w/e stalled out again. I dumped the water/fuel and there is NO WATER in the gas.
recent improvements:
new gas line last year
air valve on outside of boat functions properly.
100hr service last month
new oxy-2 sensor 2 months ago.
motor has about 2k hours on it.

The yamaha tech tells me there is an "internal" filter that might be clogged--says he has to tear down the engine to get to it---sounds like alot of baloney to me---

ANY SUGGESTIONS?????
Thank you in advance for any help!

chuck

 

I don't think a clogged filter would cause this sort of stalling- since it runs fine for a while, then suddenly dies; while if a filter were clogged it would probably die as soon as you opened the throttle, or would run roughly. Do you have a temperature gauge on it? I've seen cases where the computer, sensing an overheat, cut the fuel flow- and if this happens at speed it can stall.
Start it up and check all the water outlet holes on the back- the pilot jet ('pisser') should start within a couple of seconds of the engine starting. As it heats up, or as you apply throttle, you should see water spraying out the exhaust bypass or near the prop (depending on model). If there's no water flow, or if it's not strong and steady, have the cooling system cleaned and the impeller checked.

 

Only thing I can think of ('cos I don't know bugger all about it) is dirt in the fuel. After not using the engine the dirt can flow back down the line. After running for a while it can once again get pumped into the jets.

You may need to clean the fuel lines out.

 

Thanks for the input guys!

I had a mech look at the problem and he said it was definately the boat--not the motor.
I had just changed the fuel lines last year and thought that they could not be the problem--but boy was I wrong!
One of the lines from the tank had a plastic lining that collasped!
I changed the lines from the tank to the motor and she is running fine again!!!!!

Capt. Chuck