Hey Mike
I remember your boat now that I can see it. I met you up at Berryessa a few years ago with the Laid Back Boaters. I was driving the orange Nordic minicruiser, sitting under the bridge with Cas. I thought your boat ran really well with that panther.

I just read through this thread. My question would be what did the motor sound like at the 4200 rpms? Did it run strong right up to the 4200, or kind of "starve out" ? I had a similar experience in a sleekcraft that I put a good BBC (from another boat) into. Started right up, ran great on the trailer, but when I got to the lake, it wouldn't go above 4000 rpms. I fiddled with the timing, fuel filter, carb, an figured it needed a tune up. Took it home and it ran perfect on the trailer, but I changed the points (yes it was that long ago) and plugs. Went back to the lake and its back at 4000 rpms. I was about ready to pull the plug, when I decided to disconnect the fuel line from the tank and poke it down the fuel fill--whoa, all of a sudden I was getting 5200 rpms out of that little race boat. Turns out the screens in both tanks were clogged, and restricting the fuel flow. Fuel flow was fine at idle, and with no load on the pump, but not enough to feed the motor past the 4000 rpms in the water. All I had to do is take the sending tubes out of the tanks and replace the screens. Maybe you've already figured it out, but I thought I'd relate my experience.

Mark--"Sanger Pete"

Hmm, a real puzzle. Essentially you've lost approx 20 mph by adding a droop and PD. It seems to me that (1) the motor is OK--4500rpms @ 3500' elevation in a 21' boat sounds about right. (2) the pump is loading OK if you re getting a 100' roost 20' high. If the pump was cavitating, I think your rpms would be higher, and your speed even lower. I've had junk in my pump and had a very loose pump before, and the problem isn't from 30mph to 50 mph, it's from 0 to 15. (3) I'm not sure your boat could hold enough water to slow its speed by approx 20 mph unless it was more than ankle depth--and then it would be pretty noticable.

It sounds to me like something must be dragging in the water--maybe the droop, the box anchor, or like I read one time, "A guy went to the lake for the first time to run his new boat. He launched the boat , idled out and proceeded to run it around the lake. However, he was very disapponted with the top speed which was much lower than he had expected. Back at the ramp he found out that most people disconnect the boat from the trailer when they go boating." That old trailer was just causing too much drag.

I think I would take off the droop, although I've never seen one cause this much of a loss of speed.

Quote from: SoonerFan on January 25, 2009, 05:41:16 PM

  also I just had a droop and diverter put on !! reverse gate?? whats this??

Quote

My forward/reverse/throttle is not a combo...I have a foot pedal and a l ever for forward/reverse. what kind it is im not sure...I pushed the pedal to the floor and it had WOT...this is so weird..I had it all timed and the carb rebuilt..i took it out and from GPS it would hit about 32mph and when I use the diverter which is way cool by the way    I got down to about 28 mph 

Wild idea. What kind of reverser lever do you have? Is it by itself or part of a combo gas/reverser lever?

You said you had a diverter installed, right? That means the reverser bucket/linkage is new to the boat (even if it's used equip). The Place diverter bucket geometry and travel is "different" from what the boat had before. If you have a combo throttle/reverser control lever then maybe the reverser bucket is opening all the way but stopping the throttle cam/linkage in the control lever from going further an letting your motor rev higher.

Ask me why I suspect this and what I've been doing for 45 minutes! 

Hey GT,  I havent yet tried out your idea yet weather here has not been very nice to me....you were right the tabs were all the way down though ..Good Eye !! Im just going to pull them off....but as I was looking at them I was wondering ...why are there trim tabs on here at all ??

sweet..will do !! Hey I was reading that the trim tabs should be mounted 1/2 inch above the bottom of the boat ?? not flush with the bottom as that will cause alot of drag ?? any thoughts or clarification on this?? and by the way mine are flush with the bottom !! 

Ok all.... i raised up the trim tabs...and got another 2 mph  but the boat was porposing..didnt do this when the tabs were down LOL But at 3600 rpms I was hitting 34MPH and 3600 was WOT ??  Im wondering if my pump needs an overhaul or if this ia a motor issue ?? The motor sounded strong didnt cut out at 3600 just wouldnt go any higher 

I had it all the way down..then played with it awhile....it seemed worse when the rooster started to fly !  I just dont get the 3600 thats crazy... the pump seems to be fine I think its a carb issue maybe to small ?? what do you think ??