NEED HELP ON WHY NO SPEED

[MATTKENSETH]

I HAVE A 20 FOOT PROCRAFT WITH 1999 MERC 200 HO EFI, WITH A 25 PITCH LASER 2 PROP IM ONLY GETTING 5200 RPMS AND MY SPEED IS A VERY SAD 52 MPH AT MAX AVG OF 49 WOT.<br />COMPRESSION IS A 95,100,96,100,100,95<br /><br />ANY REASON WHY RUNS FINE IDLES FINE AND JUST HAD A NEW WATER PROPLEER PUT IN AND IT WAS THIS WAY BEFORE THAT TOO.

 

[Barnacle_Bill]

Re: NEED HELP ON WHY NO SPEED

I don't think you are going to get much more out of it. You could go to a 23" pitch which would get you rpms up a little. Isn't WOT on that engine suppose to be around 5500? I don't have a manual on those new motors. Also is your boat heavily loaded? How old is the boat? The older ones tend to be heavier and its possible the floatation foam could be saturated with water. That alone can add a lot of weight.

 

[MATTKENSETH]

Re: NEED HELP ON WHY NO SPEED

BOAT IS A 1999 <br />FROM WHAT I BEEN HEARING I SHOULD BE GETTING ANYWHERE FROM 60 TO 65 MPH ON AN AVEAGE

 

[walleyehed]

Re: NEED HELP ON WHY NO SPEED

Where is the engine mounted-directly on transom, jackplate, etc. and (if) not on transom, what is the level of the cavitation plate in ref. to the bottom of the hull. Flush, (even), below???

 

[MATTKENSETH]

Re: NEED HELP ON WHY NO SPEED

HAS A 12 INCH JACKPLATE AND I HAVE LOWERED IT AND RAISED IT WITH IT DECREASEING IN SPEED BOTH WAYS AND IM NOT SURE WHAT YOU MEAN ABOUT THE CAVITATION PLATE

 

[walleyehed]

Re: NEED HELP ON WHY NO SPEED

The "cav" plate is the horizontal "fin" right above the prop.<br />Also, what is the max throttle range RPM-wise.

 

[MATTKENSETH]

Re: NEED HELP ON WHY NO SPEED

ok decarbed the engine today and only got 53 mph.<br />still only 5200 rpm's<br />recommanded rpm's is 5800 most run it at 6000<br />so i have a problem some where.<br />the cav is about even

 

[walleyehed]

Re: NEED HELP ON WHY NO SPEED

If you have a 12" jackplate and the cav plate is even with the bottom of boat, you are 3-4" too low.<br />OK, starting with the engine's cav plate even with boat bottom, make one run at WOT doing nothing but using trim for optimum ride..note speed and RPM. come to a stop, lift engine approx. 1/2" and test again. Take notes of every run, from hole-shot to top-end. Run in the same direction every run to keep the variables as close as possible. Keep raising 1/2" at a time untill either it ventilates on top-end or blows out on the hole-shot<br />I've also punched some numbers in, and you "should" be at about 59-60 MPH at the RPM you say you are turning, which brings up this question...what type of speedometer do you have??<br />I see 2 possibilities here, #1, speedo is off quite a bit, and #2, prop is showing some very inefficient numbers for slippage.<br />Alot of questions here, but has the boat set in the water for more than 3 or 4 days at one time??

 

[WillyBWright]

Re: NEED HELP ON WHY NO SPEED

Okay, I gotta ask. Are you really Matt Kenseth? If you are, you'll know who Jason Schuler is. I used to work at the same factory that he did when he did. Who knows, he might even remember me although I doubt it. This is a test. What did that factory make?<br /><br />What is the max speed your speedo says? The closer to that that the boat will actually go has a big effect on it's accuracy. I mean if your speedo goes to 85 and your boat goes 55, it's not as accurate as a 65mph speedo would be. Basically it's nothing more than an air pressure gauge scaled differently. The water entering the pitot pressurizes the air inside the hose and that's what moves the needle. Not exactly Rocket Science and not terribly accurate in any case, but it's simple and at least in the ballpark.

 

[WillyBWright]

Re: NEED HELP ON WHY NO SPEED

I should also say that you want a 4 or 5 blade prop if you have a jackplate. A 3-blade needs to run completely submerged. A 4-blade can come slightly out of the water and a High-Five can run about even with the top of the prop tube with two blades coming completely out of the water. That allows more of the gearcase to come out of the water which means less drag and more speed.

 

[walleyehed]

Re: NEED HELP ON WHY NO SPEED

Willy, let's get some info here first before making recommendations when we really don't know what equipment he has.<br />Speedo may be paddle wheel or GPS.<br />4 and 5 blade is great if ya know they have a low-water pick-up...can't run shorter blades higher and higher .....<br />3 blade doesn't need to be submerged, that's wives-tales...let's see what he's got here.

 

[WillyBWright]

Re: NEED HELP ON WHY NO SPEED

Walleyehed, do you know who Matt Kenseth is?

 

[walleyehed]

Re: NEED HELP ON WHY NO SPEED

I can't say I do, willy...<br />email me..<br />kenneth.sanderson2@verison.net

 

[WillyBWright]

Re: NEED HELP ON WHY NO SPEED

No need to email you. Just Google his name. Or think #17 and Sunday afternoon and Speed.

 

[walleyehed]

Re: NEED HELP ON WHY NO SPEED

OK, the light bulb just came on....little slow at 2am...

 

[WillyBWright]

Re: NEED HELP ON WHY NO SPEED

Regarding the low water pick-up, I can help with that and I can do it with the gearcase you have right now. Just click on the icon above with the house and the little man and boy can I help! And it won't cost you nuthin but a ticket or two.

 

[walleyehed]

Re: NEED HELP ON WHY NO SPEED

Cool site!!<br />Your rigging listing is almost exactly what I do to a point, mostly from the transom back.<br />Converting std L.U. into low-water versions is a big part of the fun for me. Props are still my favorite though...I get to test alot of props for 3 different manufacturers that I'm not allowed to mention....yet.<br />Looks like ya got a good back ground in this industry-good ta know.

 

[MATTKENSETH]

Re: NEED HELP ON WHY NO SPEED

no im not really matt kenseth if i was id go buy me another boat that works right lol.<br />going by gps speed

 

[WillyBWright]

Re: NEED HELP ON WHY NO SPEED

Well, I'll tell you how you can raise the motor without sucking a lot of air into the water pump anyhow, MK. You can plug the upper holes of the water intakes by tapping them and plugging them with setscrews and red loctite. I wouldn't plug more than the top third, though. Only do that if you need to. It does restrict the flow a tad, but if the motor is high enough to justify it, the pump will work better than if you didn't and were sucking air.

 

[WillyBWright]

Re: NEED HELP ON WHY NO SPEED

Oh yeah. For anybody that's going to lose sleep over who Jason Schuler is, he's a Busch Series driver. Hasn't finished too many races though. I hope that changes real soon. He used to race against Matt on the local tracks. We worked at a candy factory where I maintained the machinery and he mopped floors. Just think...a racecar driver that used to mop floors. Back then he probably wished he got paychecks like mine. Now the shoe is definately on the other foot! That's my closest claim to fame.<br /><br />I worked at a Hi-Perf dealership a couple of years ago and often heard the boss being paged to the phone for Michael Jordan calls. But that don't count. Different MJ. Shucks!<br /><br />Oh, I take that back. I also knew Aaron Bohrod, a rather famous painter. When I was a kid I used to take him stuff for his collection of knick-knacks. I don't think he ever used anything in any of his paintings, but my brother gave him a bulldog hood ornament off a Mack Truck and he did use that for one of his more famous paintings.<br /><br />Oh yeah, and I once fixed Dave McClaine's lawnmower. He was one of the best football coaches the UW Badgers ever had and was a real popular local celeb.<br /><br />Back to the question, and what Walleyehed said about 3-blades...you can run a Laser real close to the surface and even break it a tad. Try raising the motor and see what happens. But with a Laser, the upper water pump intake holes won't be an issue.