2004 Yamaha 40Hp 2 stroke oil injected stalls in gear

[robbo_31]

I have recently acquired my first boat and it has a Yamaha 2004 40Hp 2 stroke oil injected motor with 123hrs on it. I had a 100hr service completed before I first used it.

The problem I am having is that it tends to stall when I kick it into gear, seemingly due to low revs. It will stall in neutral occasionally too, also due to low revs. When I put it into gear I have to give it alot of throttle then bring it back down to the revs I want to stop it from stalling. It runs like a dream when at speed, but that doesn't help when I just want to poke around slowly in the shallows.

I am not mechanically minded, but is there a way of increasing the idling revs without having to use the "fast idle" lever. Be gentle with me, I'm only new to the boating world!

[99yam40]

my thoughts are your carbs need cleaning.
Low speed passages are fouled

[robbo_31]

Thanks for the quick reply! Is that a big job? Should that have been done at the 100hr service?

I wonder if I should take it back to the mechanic. I just don't want to get slugged for them to fix it...

[robert graham]

Since you're not very "mechanical" then take it to your mechanic and have carbs cleaned, and while they're at it, have them install a water/fuel separator type canister filter on the transom....this will help greatly to prevent future dirty carb problems....Regular addition of a fuel stabilizer like Stabil in your fuel tank will also help. The jets in these carbs are very tiny and can be easily plugged by debris, water, etc. In the fuel....

[robbo_31]

Thanks Robert and 99yam40, your advice is much appreciated.

[TownsendsFJR1300]

If you have a tach, what is the idle RPM set at?

If its too low, obviously it'll stall.

With the 100 hour service just compleated, the mechainic should have caught that issue.

IMO, I would be finding another Yamaha mechainic (check his certifications). To let that engine go out the door stalling, W\O addressing it or at least talking to you, is un-acceptable..

It is a three carb set up; http://www.boats.net/parts/search/Ya...TOR/parts.html

It may be as simple as a sync, but as noted above, could be in the carbs.. If its occassional and the idle /sync is set correct, running a strong dose of Yamaha's RingFree may very well likely clear out any minor varnishing as it does still idle to some point. Highly recommended

Fresh fuel, with a good stabilizer is a must..