'03 Yamaha 200 VMAX stalling

[kmswiber]

I have a 2003 Yamaha 200 VMAX (fuel injection).

When I'm on plane (5000-5500rpm) the motor will completely stall. The motor still runs, but it is as though it is in neutral. I cannot go forward until I shift the throttle in neutral. Then I am able to shift into drive and run. No alarms go off.

Anyone have any idea on the cause? The only thing I've changed recently was putting more cup into the prop. Any help would be greatly appreciated.

[99yam40]

I have a 2003 Yamaha 200 VMAX (fuel injection).

When I'm on plane (5000-5500rpm) the motor will completely stall. The motor still runs, but it is as though it is in neutral. I cannot go forward until I shift the throttle in neutral. Then I am able to shift into drive and run. No alarms go off.

Anyone have any idea on the cause? The only thing I've changed recently was putting more cup into the prop. Any help would be greatly appreciated.

When a motor stalls it dies, so have no idea what you are trying to explain

[kmswiber]

First post, appreciate the terminology lesson.

While on plane the motor will stop propelling my boat. I have to wait until the rpm's go down, put it in neutral, then I am able to put it in gear (forward) and it propels my boat.

[rodbolt17]

sounds like either the prop is ventilating or your hub is slipping.
try a different blade design or lower the jack if applicable.

[kmswiber]

sounds like either the prop is ventilating or your hub is slipping.
try a different blade design or lower the jack if applicable.

Thank you rodbolt17...

When you say slipping, is this the same thing as the hub being spun? If so what causes this?

The motor pushes the boat fine, just every once in a while I have this problem.

[rodbolt17]

some two piece hubs can do this.
however I would place my money on the prop is ventilating, typically caused by running to close to the surface for the blade design.
ventilation,unlike cavitation, is pulling air from the surface instead of water.
next time it happens back off the throttle a few hundred RPM and either lower the jackplate or trim the motor down and see if it corrects itself.
if it does try a different prop design.

[kmswiber]

I kept the motor trimmed down, still quit after passing 4,000RPM. I brought it to a local mechanic. He's going to replace the VST Filter tomorrow. I'm going to also have him clean the O2 Sensor. Seems to be a common issue with this model motor. I'll keep you updated on my progress.

[rodbolt17]

I call BS.
you just got snapped.
please find a real dealership.
you just got ripped off.

its NOT an O2 sensor.
neither you NOR your mechanic could even try to describe what that O2 sensor does.
can you ask him to simply MONITOR o2sensor voltage?

[kmswiber]

He actually thinks it is the VST filter. Part # 66K-13915-00-00.

He isn't replacing the O2 sensor, just cleaning it, which is part of Yamaha's suggested maintenance.

I don't see how it is can be the prop ventilating. I haven't made any adjustments to the jack plate and it has never done this before.

Do you have any other suggestions?

[kmswiber]

Rodbolt17

I did have my propeller cupped recently, but over the weekend I tested wit another prop...it was the same model (Yamaha 25m-2) that had no cup added. I had the same results...What else could it be if not the o2 sensor or vst filter?

[greasyshaft]

Do rev's increase when you loose propulsion?

[kmswiber]

To be honest I don't know, b/c as soon as it happens (sudden slow down) I naturally react by taking my foot off the hot foot and my RPM's decrease.

Should I keep the same weight on the hotfoot (when I lose propulsion) and see if the RPM's go up? Does this indicate something else if they do increase?

[greasyshaft]

The revs will increase if you take load away from the engine and maintain the same throttle position, Happens when you trim out to high and prop starts sucking air (ventilation)

Try pin punching a mark on the prop nut and then a mark on the prop, see if the two points move after next trip.

Oxygen sensor serves no purpose at that rpm.
If it was a fuel related issue you wouldn't loose thrust, the engine would bog down. (Take the tech out with YDIS plugged in and monitor fuel pressure if you want to be sure)

[kmswiber]

I already replaced the hub and I also used a different prop. I don't think the hub is spun. Still had the same problem.

[rodbolt17]

dunno about the O2 sensor feed back.
no one but the original poster knows if this is a VX or a VZ 200.
both have O2 sensors but the function is very different.

loss of hull speed and an increase of RPM indicates prop slippage or ventilation.

loss of RPM typically indicates a fuel issue.

cleaning the O2 sensor is maint.
HOWEVER cleaning without TESTING after cleaning is like showering with a raincoat on.