F70 Yamaha stall

[Mario's4v6]

Hi Guys
I am the proud new owner of 2 x F70 Yamaha, after many years of wanting one I finally managed to buy 2 f70.. what great motors..

I recently had a hick up on the one eng.. it was running fine ( still in the run in ) only 6.5 hr on engine, when she just cut out, I first thought it is fuel, but fuel is fine.. then I thought something is caught up in the prop but that to was fine, I started the engine and she runs like a dream, BUT the moment I put her in Forward she cuts out, she takes revs in neutral and reverse also works, But she kept stalling in forward..

back home I flushed the eng and tried in forward and she was ok again.. any idea ?

[99yam40]

My guess is not getting enough fuel to take the load of the prop in water.
reverse does not load it up as much

[Mario's4v6]

ok, but I have 2 brand new fuel filters, same on both sides. and on diagnostic is showed nothing

[99yam40]

fuel pressure should be where Yamaha designed it for the system/motor to work properly.
it does not monitor the pressure.
you need to test to see if it is staying up as it should.

[Mario's4v6]

Ok, will have it checked, but sjoe, on 6.5 hours.. these eng dont have issues..

[greasyshaft]

So the engine stalls right away as soon as you go into forward?
and if they have only done 6.5hrs they should be under warranty so I wouldn't bother tutooing around with them
Might pay to have the engine plugged into ydis at your local dealer