Been trying to research what the differnces are. I hear a ton of good about the new Mercurys. Does anyone know if Mercury has figured out why some of their motors were going in to "Guardian Mode"?

Any input would be appreciated.

I am torn between the Yamaha or the Mercury. Mercury sure makes it tempting with the longer warranties!

The standard Opti has been around since the the late 90's and is a good fuel efficient motor. The XS series is straight from the hi-perf division and need to be on lighter hull boats and the Pro XS series is a production cross between hi perf and standard and works very well with most of todays bass boats. As for your last question we have not heard or seen this happening for no apparent reason.

the main difference (from my understanding) between the XS, and Pro-XS is

1)the XS is built by mercury racing. one man assemblies the upper end, and another man assembles the lower unit. once complete the engine is run for 1 hour on a dyno, and any tuning or adjusting is made right there.
2)the Pro-XS is built on an assembly line, using the exact same parts as the XS, engine is not run, but boxed and shipped.
3)The Pro-XS has more warranty than the XS, not really sure why, but that's the way it is.
4)the XS has a gray lower unit, the pro-xs is black.
5)the XS has a slightly higher rev. limiter, but still makes power at the same place as the XS. around 6K rpms

hope that helps ya.

Haven't heard of the Guardian mode problem at all.

The beautiful thing about these engines are their fail safe modes. And this isn't just Mercury's either. ALl the DFI engines pretty much have them now.

If a problem surfices, and the engine detects it in time, the guardian mode takes over to keep the engine from damaging itself.

However, just going into guardian mode on it's own... haven't heard of it as mentioned.

I think Mercury has really stepped up to the plate in the last 5-7 years with their engines, and have gotten the system down pretty well.

I wouldn't hesitate at all buying a new or used one.

When I got my new boat, the dealer made a point to tell me not to rev the engine to high rpm's while in neutral or it might possibly go into "guardian mode". Not really sure how big a problem it is, but it seemed to be an issue with him. The motor is a 300XS.

Great info. I appreciate all the data.

Thanks to everyone

It will beep if you rev to high in neutral I do know that

Yep, the new smart craft engines have a rev limiter while in neutral. If the engine goes over 2000 rpm, it will beep. If it is done again and goes too high, it can and will kick the guardian mode in. This keeps the engine from damaging itself by freespinning and not being under a load.