Bottom - I switched from 150 to 200 on two separate boats and found the differential very significant in these areas:

1. lift onto plane
2. hold plane at lower speed
3. top end

Top end differential was approx. 10 mph in both cases.

So, if your 140 may be producing approx 10 % low, and you switch to a 150 that produces approx. 10% more, affect would be significant.

There seem to be good volume of solid, used Evinrude 150 loopers for low cost, maybe you can wind up selling yours, and getting 150 for low total dollars

I really would like to get another year or two out of this motor and then my ultimate plan is to put a relatively new 200 on her after rebuilding the transom just to be safe...so I'm hoping I can just get this motor where I need it to be and accept the lack luster performance of a 140hp.
Ferminator...what kind of electric tach would you recommend I test this motor with to see the accuracy of my omc tach?

I've always had good luck with teleflex instruments. And the 140 is a STRONG engine. OMC origanally planned on dropping the 150 when they came out with the 140 looper because it was so strong. Problem was it has the power up top, but not down low. The V-4 just can't match a V6 down low. I know my 140 I had on my 18 foot bowrider outran a 18 foot hydrostream with a 175 EVINRUDE on it. The kicker was I had 5 people o nboard, and he was by himself. Should have seen his face when I pulled laongside him, hit it, and walked off and left him. When I got back to the ramp he was over demanding I pull my cowling off because he didn't believe I had a V4 under it. The 140 put down a GOOD 150 when they were running right, but if they aren't perfect, they won't hardly get out of there way.

What's the easiest way to measure REAL rpm - what's a digital tach and how hooked up ?

How Long To Reach Top Speed
 

By my count it takes about six or seven seconds to reach top speed with my sweet, never-rebuilt 1989 Evinrude 200XP, but you be the judge. I shot this little video at last year's launch:

http://toplaw.com/page10/files/Boat%...20-%202015.m4v

[For unknown reasons I can't upload that video to the V20 site, but for anyone who can get around the problem, feel free to do so.]

You hit a small wake and cut the power ?

Wanted to see the full speed, trimmed out, maximum performance with your comment to confirm speed and rpm ?

I watched the video, and now I want a refund !!!

I just found him a 200 mer yesterday on crigslist he was going to pick it up!

Bgreen - that's the only holeshot video I had on hand, but I'll try to do a more extensive one this season. Can't wait for spring launch.

My V21 may hit 100 mph, maybe more off a cliff, but I'm conservative and don't want to push it that hard...

I'm at a loss here....

13.75x17 ss prop, 13 7/8x15 aluminum prop, 13.75x13 ss prop

You say all three of these props gave you the same RPM's at WOT? Comments about aluminum being different than SS notwithstanding the two stainless props are 4 inches of pitch different, they should give you way different RPM's at speed.


The tach sure seems suspect, if not something is surely wrong.