XB RPM Question

[ThunderCat]

I have heard a lot of different numbers for the max rpm on the XB's. Mine is a 2001, and it states 6100.

I have heard 6150, 6250, and 6450. I always thought it was 6250, but then I was told it is set at 6150... but people have told me they have ran their stock xb to 6450 I believe.

I want to say it's between 6150 or 6250. If I am able to run at 6450... then my assessment is all wrong.

Mine is a 2001 XB.

Thanks fellas.

GOD BLESS.

[CRIMSONGAMBLER]

Tyler, the guy i bought mine from(bbc member) said he has turned it 6300.

[Blue Steel]

Tyler...If your motor has 6100 why not run it at that?

[jayfaro]

Mike,
Tyler and i got to talking yesterday and the RPM range for the XB's came up. I always thought these XB's build their best power between 6000-6200 and yet, my motor plate states "6100 Max RPM". When i first bought this boat, the 26 Trophy was far too small and I KNOW I ran 6400 for a brief time and i never hit an actual hard limiter where the engine cut power. I have heard the limiter is anywhere between 6100 and 6450 though i cant confirm what it is and if you ask 10 people, you could possiby get 10 answers. Tyler was talking about having the engine cut power once it hit 6150. It just doesnt make a lot of sense to have the Merc rated "Max RPM" at 6100 and yet the motor build thir best power at as high as 6200...if indeed it really does build its best at 6200!

Jay

[Blue Steel]

6150 is the soft limiter, I had an XB, propped to run 6000...why take the chance of hitting the hard limiter at over 80mph, could be diaster in the making.

[EuropeanAM]

<table width="90%" cellspacing=0 cellpadding=0 align=center><tr><td>Quote, originally posted by Blue Steel &raquo;</td></tr><tr><td class="quote">6150 is the soft limiter, I had an XB, propped to run 6000...why take the chance of hitting the hard limiter at over 80mph, could be diaster in the making.</td></tr></table>

+1

Some of the calibrations used in the fuel or ignition ECU's varied (and as we all know, some of these have been CHANGED).

For a stock, un-modified engine, refer to the serial number decal plate (usually affixed to the starboard side of the swivel bracket). The WOT RPM figure should be printed there.

Keep in mind.... analog tachometers are notoriously inaccurate- you may (or may not) be reaching the RPM you "think" you are.

[jayfaro]

Thanks for the info guys...i'm actually glad this was posted. I was always under the impression the closer you could get to 6200 rpm at WOT would be the range that would build the most power. The Bravo I'm running (or was running for 15 minutes after i got it back from mark until i hit a submerged tree! ) would run to right around 6100...Don, its true about the Tach as well. I know occasionally i have to apply the old one finger knuckle to it as i'm driving down the lake to make it read accurately. By the way, what exactly is a "soft" limiter?

[rdb1028]

Another question is there a digital tach that will work with the XB since it's not smartcraft ready? thanks-

[ThunderCat]

i agree with you mike. im not going to push it past that. i just had wondered since there were so many different speculations as to what was the best power range for that engine. I want to keep mine propped to run 58-5900 rpm. I liked that feeling a lot better. I already knew the prop I have on it would be slower any how.

i am fine with, my hole shot and mid range are now, to me... out of this world... i will have another prop set up for big lakes....

thanks

[EuropeanAM]

There are a few "inductive pickup digital tachometers" available on the market (primarily marketed for small engines, but suitable more most any spark ignition engine).

Just make sure that it's capable of giving a 2-stroke output (which is DOUBLED that of a four-stroke output, since the spark plug fires once for every complete revolution of the crankshaft).

[Glen B]

<table width="90%" cellspacing=0 cellpadding=0 align=center><tr><td>Quote, originally posted by ThunderCat &raquo;</td></tr><tr><td class="quote">I have heard a lot of different numbers for the max rpm on the XB's. Mine is a 2001, and it states 6100.

I have heard 6150, 6250, and 6450. I always thought it was 6250, but then I was told it is set at 6150... but people have told me they have ran their stock xb to 6450 I believe.

I want to say it's between 6150 or 6250. If I am able to run at 6450... then my assessment is all wrong.

Mine is a 2001 XB.

Thanks fellas.

GOD BLESS.</td></tr></table>

[kllr bee]

6250 is the limiter on a 250 XB.
Richard