How long to reach top speed
 

I have a 140hp johnson on my v20, and also a lot of time on my hands since its winter and I've been thinking after riding in a friends Grady White that it takes way too long to reach my top speed.
I start trimmed all the way in, hammer the throttle and trim up...before I lead the horse to water..how long would you estimate your v20 takes to reach top speed?

Do you believe your outboard is lugging?

With a 140, assuming it's still producing proper horse power, and assuming your hull isn't holding extra water weight, it should lift to plane, and top out within maybe 30 seconds give or take.......

Maybe take a compression check to confirm outboard power per cylinder.
Best of luck.

Compression checks out, pulls strong for what it is, my rpms are low which is something I have to play with this year, it seems like props are not effecting my rpms can't get above 5200 even after bouncing around between 17, 15 and 13 pitch props
Takes about 30 seconds to top out so I guess I'm not doing too bad, just would like to see more than 32 mph out of her and get the rpms up

X2 what bGreene just said.

So many things can effect the not only the time it takes to get on plane but also the performance. Boat weight (a gallon of water weighs roughly 8 1/4 lbs). If the foam in your hull is saturated that can add hundreds of extra lbs of weight to the hulls weight.) Cooler filled with ice and soda and beer? Add up the weight from that. Tackle? Number of people, amount of fuel in the tank, extra fuel tank(s). Every pound equals a longer time and the harder your engine has to work. Even the distribution of the weight has an effect. Then there's the engine itself. Is your fuel/water filter clean? Are the carbs clean? Fresh plugs? Lower unit have the proper amount of clean oil? What about the prop? What pitch? cupped? material it's made from? Dents or dings? number of blades?

The point is that it's almost impossible to second guess what your particular boats' specs are. Give us some more info please.

mawshj
 

tell us about your friends G.W. 32mph is not shamefull with a 140. also the additude the boat goes thu while getting up can make the experience seem way different. ie the hull can rise gently straight up or it can nose up then slowly return to level. often depending on your trim of the motor

Bottomfish.........I believe a strong 150hp on V20/21 runs top speed around 36-42 mph depending. The late 90's Evinrude 150 loopers were more like 165 hp at the prop, and I believe the Merc's also in that range.

I suggest you consult with a long time Evinrude dealer/mechanic to discuss how your year 140 performed and such. In my area, Eddie at J&J Boat is 2nd generation Evinrude master tech and I'm sure would be happy to speak with you on phone. 856-456-0102

32 mph may be close for the state of your outboard and hull, but the low rpm suggests other factor at play....

Try another tach. That engine NEEDS to reach 5600 rpms wot for it to perform properly. the 88 large bore is a bit more forgiving than the earlier small bore engine, but they're all sensitive to propping. I know my 86 with just a 2 inch pitch change in props could go from topping out at 5900 tpm's and 53 mph, to 5100 rpms and 40 mph on the bowrider i had it on. Propping is key for a big v4 looper to run properly.

I'm using a brand new omc tach so I'm really hoping that's not it, I might get one of those tiny tachs as I hear they are pretty darn accurate just for testing purposes.
I have tried a 13.75x17 ss prop, 13 7/8x15 aluminum prop, 13.75x13 ss prop, all 3 blade props and they all read 5200/5100 rpms
I rebuilt The carbs at the beginning of the season, new spark plugs link and sync and fresh lower unit oil
The boat is not waterlogged as far as I can tell, this 32 top speed and top rpm is whether I have 4 people and a cooler and full tank or I have just myself and no gas, I might lose 1 mph or so but it's pretty dead on and that's according to gps i don't have a speedometer

The gw was a 21 walk around with a 175 johnson of a similar vintage...I just guess I didn't expect that much of a difference with 35 hp and a similar boat, he also tops out right at 40mph

Hmmm... I know this isn't scientific, but your 15 pitch alum prop and your 13 pitch SS prop are generally considered to be the same for ballpark numbers. Reason being the alum prop flexes more than the SS. A general rule of thumb is a SS 2 inches of pitch lower than an Aluminum will give the same performance. So you seeing nearly the same numbers between the two isn't that far off. But pay attention to what TheFermanator said about your engines power band. If you're actually that much lower in your rpm's then something isn't right.

Since your speed is about what I'd expect for a 140hp engine my first guess would be your tach is off. If you can, try a different one for a test without doing anything else to the engine and see what you come up with.

I will say of all the tachs I've had, my omc tach was off the furthest of any of them. I was propping my built 225, and it said I was turning 5500 or so, dead where I wanted to be, problem was it didnt sound right, then one day it bumped the limiter. I knew the limiter was 6700, so I hooked up my digital tach, and sure enough it was off almost 1200 rpms at wot. So dont assume it being a new factory tach makes it right. Also, theze tachs are driven off the charging system, so any charging issues can effect them as well. If you have the 35 amp charging system, it is common for the magnets to come loose in them, and cause tach issues.

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.

Not always. 15 pitch doesn't equal x rpm and y speed for every prop. Some basic props can run say 5200 in a 17 pitch at 45 mph while a different style 13 pitch could turn the same 5200 at 42 or 43. Pitch is just one meadurement when it comes to props. Some props also have what we refer to as progressive pitch where the pitch varies across the blade, or you can have one with alot of cup in it, larger diameter, different hub, and so on.

Also, along with everything that TheFermanator just said, don't forget that different materials will also effect engine RPM's. You mentioned both Aluminum and Stainless Steel props.. Under load, while being spun against the resistance of the water, they both will flex, but at different rates. The aluminum more so than the SS. The amount of that flex also effects the final RPM's vs SOW of the boat.

And don't forget number of blades and prop slip. We went from 21 pitch vengence props on the neighbors boat to 18 pitch 4 blade michigan wheels(both stainless). The boat runs nearly the same top speeds, turns slightly less cruise rpm's at higher speeds, jumps on plane instead of just looking at the sky wishing it could get on plane(had have everybody move forward, trim both drives in, and run the tabs down all the way to plane out before), and runs 100 rpm's lower at wot. The searay 250 I did a few years back had similiar results. Went from a 17 pitch vengence to a 16 pitch mirage style, got it off the limiter, planed better, and ran alot faster.

Speed
 

My 1977 had a 1977 evin. 140 when I towed it home from Florida early Dec. which we checked out and they said it could run but the compression and condition were such we'd never get max performance out of it, it likely had been overheated as well and it wasn't worth putting money into rebuilds...technology. So, I looked around, found a 2008 Evinrude etec 175 with 300 hours and careful maint. history from a dealer and repowered. It had been running a 21' bass boat with stainless prop so they needed to re prop it for a deep v hull and started with an approx 14" or slightly less x21" pitch. Popped it in the river and ran it wot to 45 mph on gps. However the rpms were down so they re propped it with a 19" which it has now and the rpms should get to the max range of 5500 to 6,000. Not sure what the wot speed will be but it should cruise pretty well. If I had kept the 1977 140 I bet it would not have gotten more than 120 hp which is not enough for a big deep v hull in my view. The 175 pops it right out of the water they told me. I couldn't be there the day they did the prop work on the river but am eager to get it out when weather breaks now. It's ready and functional.

get to plane and speed with etec 175
 

I repowered with a 2008 etec 175 on my 1977 V20 and got to use it three hours Friday. The two stroke is a torque monster pushing a 14.5" x 19" pitch aluminum evinrude new prop.

Three hours of use, mostly cruising at around 2700 rpms and about 26 mph. 3000 rpms and 28 mph, 3200 and 30 mph easy cruising. 4,000 rpm and about 40 mph. I ran it into the wind briefly wot and it hit 48 mph with the nose trimmed down. I did not do it for long but it was doing 5,000 rpm and later learned when I started trimming during cruise if I got the nose up a bit it added 200 rpm and 2 mph so I think trimmed wot it will hit very close to 50 in flat water with just me in it and full tanks.

Up on plane with gradual acceleration...how about the torque monster does it at any rate you want. It throws it up on plane faster than any boat I've ever had...very few seconds if you want and no bow way up in the air stuff with the step lift..hit it medium, go more and you are up as fast as you can handle the throttle.

The engine is so quiet you can barely hear it. If you are idling along at 4 mph you can't really hear it at all.

In three hours of use constantly I consumed 7.6 gallons of gas from the starboard 20 gallon tank and never touched the port one. That's an average of 2.5 approx. gph which is way better than my former Mercury 3.7 l four cylinder 170 hp inboard on a Wellcraft 190 American i/o.

The new engines, this one had 300 hours on it and just serviced...are just phenomonal and lots lighter weight than the four strokes with way better torque as well as a two stroke. Smoke? Using the Evinrude high test synthetic oil it smokes not a bit and uses/injects from the oil tank based on computed/sensored need at something like 75 or 85 to 1 ratio depending on speed and rpms. Best engine I've ever seen.

The boat tracked easily at 48 mph and handles any wakes or waves I saw on the river like they were nothing. There's a reason they sold so many of these.

When I got back to the dock and got it on a windy day back on the trailer solo and pulled the drain plug...dry as a bone.

I'm pleased. The data is from my experience with a specific motor. Late March, 2017 at about 60 F outside.

somebody posted in this thread that we should post some videos. i think we should do that! give readers a good idea of what to expect and too back up some of these claims.

lets have a virtual race! quickest to plane, quickest to top speed and fastest boat. im willing to wager a beer, lol

last week best i could do was 44.9mph SOG
best cruise (gps/smartcraft gph) 2.9mpg
and after switching props to a 17" mirage plus (1.5:1 gear case bravo)
i can get up on a plane in about 3-4seconds, about 50 feet