Got it. I know it to be risky by myself but the motor height was the first thing I checked. The lighter 200 was perfect mounted in the top hole the cav plate was right on top at 40 mph. The 250 seems to be a little low, I can barely see the top of the plate while underway and I mounted it using the second hole. It has a tiny bit of spray coming off the lower on one side only. 3/4" higher should do it. The bracket was mounted per the directions.
The Mirage 19 will be my next prop to test.
BTW I have been posting for a album. I need to reach 100 posts. LOL
At this rate my album will be here next week.

Nothing to report. Bronchitis slowing me down. Hope the boat is immune. I've looked into actual hp numbers on the 250 EFI and I think with a little more setup it might reach 58mph.
I have been second guessing the decision for more speed. I think this old girl deserves better treatment than what she is getting right now. You know, run hard and put away wet. I am a gearhead but I don't really have the speed bug. Besides fat people get distorted over 55mph...

:hide:

Just a question--Is not the 250 over the rating for the boat>>

Mine has a rating of a 235hp.

Just curious if these boats varied on the HP ratings for different years.

I'd raise teh engine to the top hole and try the 21 Mirage, if you get the engine too high, you will know it, then you won't have to wonder how it will run rasied anotehr hole, its allways easier to drop the engine down a hole than raise it. Liek I said, my friends 20 grady spins a 19, its a heavier boat than a V, plus he has a big T-top with full cnavas. That 225 Yamaha spins teh 19 with no problem. I don't remeber the different gear ratios on teh Yamaha verses your 250 Merc (1.75 i think), but I'd guess you should be able to spin a 21.

The hp rating on the boat in 1983 was 200 or 235. I know the early 20's were rated much lower. Going back to 1970 for instance there was no such thing as a 200 hp outboard. The max rating was 135 in that year. Several factors have led to the change in hp rating over the years. At some point I belive they changed due to Wellcrafts decision to go with the OMC SEADRIVES.
You raise a good point and in doing so opened the preverbial can of worms. What is the law? My 20 has no plackard for hp max persons etc.
I really don't have plans to run this package for long but say I get pulled by a wildlife officer, what would happen?
There is a really cool website for fast boats called SCREAMANDFLY.com, It is absolutely insane what motor and boat combinations you will see there. I don't think it really matters what you put on the back of the boat until it is
1. Time to ante up for insurance or
2. When you are sitting in court trying to defend your bacon after something went terribly wrong. :cen:

I know a friend of mine has a 21 KEY WEST with a 225 YAMAHA 4 stroke and he spins a 19 pitch STILLETTO to about the same RPM's that my 225 EVINRUDE spun a 15 STILLETTO, he maxed at 6100 running 52 and I maxed at 6400 running about 50-51. Those 4 strokes have a pretty deep gear ratio to them in the lower unit.

Ok, local marinas looking to see what they have for props. One said YES over the phone to several 21p test props and when I showed up in person you would have thought I was speaking Russian, Nyet!!.
Raising the motor to the highest position on the bracket, Friday. That idea is genious. Tweaking on the throttle plates to adjust idle down a bit.
My motor guru claimed mid-50's. He stated that I would be fighting the wind with my t-top and console as it is currently set up.
Since I have totally hijacked this thread I would offer that a light 20 with the proper setup and 250hp would be able to achieve 60mph without question. It would be cool to start with a CC and install a small console all the way to the step for the casting platform.
Bare essentials with a bucket seat that just offers a view over the bow.
Or maybe a cuddy with a small windscreen. 60 would probably arrive with less than 250 hp if the hull was light enough.

Does anyone know the actual HULL speed of the V-20??


As far as the HP deal--As I understand--it just will not meet CG approval and as long as you do not have a incident because of HP you should be cool--other than maybe insurance--make sure they know what is on the boat for power to cover your Butt.

RR, look thru the gallery at "on the Fly's" boat. As far as the hp, change the stickers on the cowl to a 225

Spare, I have looked at all of the galleries. That is a small console. I call that the day boat look. Simple, functional and beautiful. It took me 10 years to do my 20 and that is too long. It gave my brain too much time to figure out how to make it overly complicated. Bells and whistles are nice but simple and functional are the reel roots of these boats IMO:)

BTW, The 250EFI has no stickers on the outside to indicate HP it was recently painted, in a wind storm no less. Hoist the 40 lb lid off and the ECU's have 250 stickers all over.

Update
 

Since I can't afford to fly spareparts down to drive my 20 to 60mph I have taken it upon myself to go on a diet. You know increase my power to weight ratio.
I got a 21pitch prop, repainted the lower and have been working to resolve all motor issues. Hope to raise the motor this evening, set the throttle position sensor and be ready for a lake test this weekend.
:sun:

Good luck with it Ridge, and make sure you have your shut off lanyard attached!

Thanks Nipper.
 

I agree 100%. Kill Switch Lanyard to be worn at all times when boat is in motion, no matter what speed. In addition we will have a full life vest, no riders and a couple bystanders with 911 on their speed dial until we see how it reacts. Hopeful to get some pictures. I don't care to take pictures while driving but will improvise there, maybe a quick shot of the GPS at maximum velocity.
54 was without drama, no ill tendencies except you have to train yourself to watch for big waves much farther ahead. I posted it before, the extra speed is a novelty that won't be used much. But, I would be lying if I said I wasn't having fun with this endevour.

speed
 

anyone know how much speed is lost with rough bottom paint , compared to a smooth slick finish ?

Welcome aboard. I was curious as well. I saw it was answered in another thread.
Trip to the lake was a huge disappointment, 96 degrees, no wind, too much prop, motor too high, less top end and the motor malfunctioned.
It would only turn 5400 trimming to the moon. I had a rider that saw 52 mph on the gps. The motor will need to come down two holes. The center of the gearcase is now 2" below the bottom of the boat with the 30" setback. On plane I can see the water 2" below the ventilation plate and at this height the prop is surfacing with trim at wot although water pressure was always good. The prop is ventilating somewhat in the turns. The setup was not right and going to the 21p Thunderbolt was too much prop. I will have to send it off to be re-pitched since I bought it.
The motor dropped off about half way thru the test session. Something crapped out with the fuel system or the ignition. It wouldn't even get on plane. I don't think I hurt it too bad, it still has a good smooth idle. I am happy it died in the lake instead of the Gulf of Mexico but :head: NOW WHAT?

With respect to props, Ferm you were right on the money, I should have tried a 19 Mirage. I really thought it might turn the 21 with the motor raised up. I may have already seen the highest top speed. The giant diameter of the new prop really made a huge difference.

sorry about pointing you in the wrong direction on the 21, I guess Ferm nailed this one, but you do need to stick with the same style prop, just 2 numbers down

Hey, not the wrong direction we are getting there bit by bit. If I was to do it over without input I would have made the same mistake. I should have known better. I had the info right in front of me but chose not to use it. With the 200 I ran a 17p Quicksilver to 6300 @ 48 and went to a 17 mirage and dropped 500 rpm with a top speed of 46.
I agree, the style of prop is the correct choice for all around performance. It has more rake and cup than the prop I was running to 54 mph. This one carries the bow a little better and still has a great holeshot. If all holds true I should be just right with a 19 Mirage, Ferm nailed it alright.
I can keep this one for a spare or make it into the right prop by sending it out. Any thoughts there?

250 hp isn't enough. I tried but will concede the trial in defeat.
You could reach 60 with a modified motor I think it would take 280 or 300 hp on a light version set up for speed. I never felt the boat was out of control at 54. It handled great. There are some out there now running 54 or better with less hp than what I tried. I have concerns about the additional weight of the added hp and just how practical is it?
Max hp = 225. That is a great recommendation IMHO.

I'm pretty sure a MERC 280HP 2.5L would push a V20 up into the 60 MPH spectrum. Then again the V20 is a fishing boat so why do you need to push it that far? The only reason I built up my 225 on my HYDRA was for economy, the added grunt was just a bonus. I knew that the lower cruise RPM's on that big looper would help keep the fuel sucking in check, and the porting let's it wind up easier as well to help out. The 225+HP at the prop is just a bonus for when I need to rocket the boat fully loaded on plane in 15 inches of water.

Update on speed.
 

A bad stator and a long wait on parts have been slowing me down. Went to River Ranch this past Sat. Lots of nice rigs there "testing" top end. I took a good friend over to watch the hot boats. We put in at Port Hatcheneha and ran past River Ranch which is somewhere around 35 miles each way. The 250hp Merc pushed the 20' Center Console to 57.0 mph on the GPS turning the 21p Thunderbolt to 6000 rpm.(on the limiter) The conditions were less than perfect. Steady 20 gusting to 30 out of the east. Best number was seen running into a headwind of 15 with a light chop on a leeward side of an island, never saw that number again. It will go 55 in dead calm water and the prop never looses bite in heavy chop. With 600 lbs of people full of fuel and water, 94 quart igloo slap full and more tools than I normally carry just in case...
The handling of the boat was nothing less than predictable. A steady cruise at 4000 rpm put me at 38 mph. Very close to the 40 I was searching for. There is more speed in it if someone wanted to bankroll my efforts but I think the current setup and prop is good enough. Thanks to spare as he was correct on the prop. The motor was laying down on top end last time out due to the stator, I just didn't realize it.
Captpete is the winner, he guessed 56. pm forthcoming. :beer:

Hey, I don't Pete has won just yet, I have yet to have a turn at the wheel(you did say it was insured, right?)

You know I'm not that far away from him. I managed to get my old PRO-LINE up from 47 tops to 59.7 with a prop change and driving it like a maniac. COuld have probably had gone faster, but the wife was screaming at me loud enough to be heard over almost 60 MPH winds and a 2.5L MERC XRI turning 5600 RPM's:fight:. Don't know what the big deal was about it, I only had the engine raised up 4 inches and enough trim that the bow was gliding. The only real wake was coming off the prop in a rooster tail.

wonder how a 23 would spin on it(yeah, I know, leave it alone)

On the limiter again. The 250 EFI does have some moxy. It idles like it has a 3/4 race cam and I believe someone has tinkered with the tuner as it is pretty loud. Setup is near perfect but a prop change may squeek out a few more mph. Driving it like I stole it already Ferm.
Insurance? Well I could pay the insurance premium or I could buy a 23 and try it out. What do you think spare? LOL
The racers at River Ranch suggested a Rev4 to help keep the bow up. I will not sacrifice holeshot for top end but I may try something more after X-mas. It is a $$$$$ thing... I do not have any issues with porposing or handling, it never felt light until we got into some heavy chop at WOT. MPG was surprising, we logged 72 miles on the GPS and burned 26.5 gallons of premix for 2.7 mpg average. There was a lot of cruising at 25 to 30 mph due to the 2 to 3 footers we encountered running across lake Kissimmee. BTW the gimble style drink holders don't work in sloppy weather, soda everywhere.
We pulled up to the shore to watch the go-fast boats in the ditch and I was surrounded by v bottom superboats. I could not help but think that the old Wellcraft v20 steplift was the inspiration for many of the hulls that were there.

Damm,
Ridge if it was not for that cooler of encouragement you loaded up I would have nailed it..Congratulations Capitan and good job Ridge ..

A REV4 shouldn't hurt your holeshot, if anything it will make it stronger. And it would be a much better prop for the lighter weight of the V-20 VS the MIRAGE.

Better holeshot you say, really? It gets up fast now.
What pitch should I try? The 21 Thunderbolt I have now is the Quicksilver clone to the Mirage. I have 11% prop slip when I plug in the numbers. The motor is as high as it needs to be, I can see the water rushing around the lower unit about 1/2" above the stock water pickup and well below the cav/vent plate. I can trim it out without losing bite or water pressure, when over trimmed it throws a nice rooster tail but speed don't come from there. The setup isn't far from optimal now, I am not totally handicapped, I have been rigging boats and prop testing since 1987, I just don't know squat about conversion from 3-blades to 4. Any ideas on how many rpm I will loose going to the 4-blade with the same pitch?

You guessed 54, I needed another person in the boat or another giant cooler full of adult beverages... Thanks nymack.

http://www.propgods.com/content/propellers.aspx

I posted this in another thread, but it gives you a general idea of what MERCURY's props do. The MIRAGE is designed for large heavy boats with big HP, the V-20 isn't exactly big and heavy. The REV 4 is designed for lighter boats and top end. The VENSURA is similial, but is basically a 4 bladed MIRAGE.

if your trying to get the bow to lift, what about a tempest? I've never had much luck with them on boats I've tried them on, but I figure they must work on something otherwise they wouldn't still make them. they have more blade surface than a laser, and seem to work better on heavier boats liek the V(vs a bass boat). As far as four blades, my experiance has been they will lift the stern, pushing the bow down, unless its a high rake fourblade and they generally work better on light boats. If you can't find a 23 Mirage to try, carry your 21 to a prop shop, tell him you need 200 rpms less and soem bow lift, a good shop should be able to dial it in on teh prop you have.

Thanks Ridge. I would have to say it was nothing more than an educated guess based on the speed of my v with its 225. You can never have too much power. Those 3L Mercs do sound mean don't they. Lots of luck with your new setup.

Prop Gods recommended a Tempest in a 23p. My prop slip was 14% not 11% as reported. They suggested the Rev-4 was not faster than the Mirage in their experience. Tempest has the same blade design as the Rev-4 just 3-blades with lots of bite. The Tempest turns a few more rpm than the Mirage in the same pitch. Prop is on the way for testing..
Keep you posted.

You may need to raise the engine even more with the TEMPEST from what I've heard about it. It likes to run with a little air in it to help it spin up.

Thanks Ferm, I appreciate the input. With the Mirage, I had to lower the motor one hole from the top as the prop was starting to loose bite in the turns. Water pressure was down a bit too. Right now it is one hole from being as high as it will go and still have adequate water pressure. I will see what it will do. I may just need a little tweeking on the Thunderbolt, as suggested by Ken.

Prop arrived today from Ken @ Prop Gods. Excellent service... I have had to wait longer for a gallon of 2-stroke oil from my local shops. Test time.

The answer to the question is ...... wait for it ... Yes, the way to make it run much faster than 50 is to buy and use more hp. Saturday I was anxious to run my 20v cc with the 250 EFI Merc on a 30" setback bracket. The weather was perfect, wind 4-5mph out of the north creating a very light chop and a cool 69 degrees at 8:00 am. Took a snapshot of the boat in the water and proceeded with testing. Light setup for the test, one person, cooler full of drinks and ice, 1/4 tank of fuel, no water in the holding tank.
The first 20 minutes was for warm-up. The 23P Tempest gets the boat out of the hole very well. It cruises at 40mph at 4000 rpm. WOT with no trim gives 5300rpm at 54 mph. Add trim and she starts to fly the bow. Best speed into the wind was 60.4mph. With the wind I saw 62.0mph. The speed was measured by GPS. The motor would accellerate hard to 58 and then take another 15 seconds or so to climb to the max velocity. The boat chine walks a little above 58 but can be driven past it. I attempted a few pictures of the GPS at speed. I got three pictures at 61.6mph. I saw 62mph a couple times but never got the picture. The refresh rate on the Lowrance was trying to keep up with the speed IMO.
The speed kept increasing until it finally hit the limiter again at 6000 rpm.
It may still have a mph or two in it but I am really done now. I bought the prop as I found bottom in the lake twice while trying to find my dry box that blew out of the boat whan I wasn't looking. Special thanks to Shaun Torrente (best driver I have ever seen) for selling me a hoss of a 250 Merc, Fred Van Wagoner for the fairing and paint job on the boat and my loving wife who has no idea how much all this cost. A few others for their input and support, Ferm, Spare and last but not least wellcraftv20.com. It was fun. On to new thinks.:beer:
Pics Attachment 1450

Attachment 1451

OK, I guessed 59, any one closer? And I guessed the tempest, although I didn't have a lot of faith in it. Good to hear you hit the numbers. On a bet, I would have figured the Mirage would have given the best numbers, good to know what props work

I haven't seen the rating on a 70 model, my 1972 was rated for twin 115's on the transom info plate.