P4 starting point. PTPad

[Judson1]

This may have been asked but what are you getting the rpms from? Smartcraft or analog gauges?

Smartcraft

[basshole51]

http://www.bbcboards.net/showthread.php?t=22038

some good info for you here.

[Judson1]

http://www.bbcboards.net/showthread.php?t=22038

some good info for you here.

Thanks. I’ve been reading some of them. Pulled the plugs and they were pretty bad. I cleaned them but will get a new set tomorrow .

[Grant2]

I’m running a 24 Fury and mine gets down the lake very well. You may try running one and see what it does.

[Judson1]

I’m running a 24 Fury and mine gets down the lake very well. You may try running one and see what it does.

4 or 3 blade?

[Judson1]

I’m running a 24 Fury and mine gets down the lake very well. You may try running one and see what it does.

4 or 3 blade?

[JayLaw]

Attached is a picture of my setup. 13 P4 with 200 Optimax Pro XS.I will look back through the threads to gain more knowledge but since I had a specific question ted walking with both props. Hole shot is good. Water PSI was as high as 20.
Im looking to raise in increments unless someone says I should not.
Attachment 428208
Thanks.

In this picture you are about 1/4Inch above flush. The inner plate moves the outer plates does not. The area on the inner plate that is visible just above the black side plate, shows the inner plate to be about 1/4-3/8 inch above flush. Lower this back down to where tis area is flush with the outer plate. You definitely still have other issue if you can't get above 5400 rpm but leave the plate flush until you get everything else figured out. New plugs should help, but really need to verify that throttle setting.

[Grant2]

4 or 3 blade?

3 blade

[Grant2]

Send me your number and I can show you a video of the whole shot and getting down the lake very quickly.

[Judson1]

Had some time to run today so I did. I cleaned the compressor strainer and installed new plugs earlier in the week so I wanted to make sure everything was ok. I haven’t taken the boat to a mechanic. But according to what I’ve seen about the throttle position mine seems pretty well wide open. There might be 1/8 to 3/16 gap between the throttle and the stop on the engine.
Todays runs were with maybe a half tank of gas. Solo. And a light load with livewells empty. Temp around 55. I still have not seen 5400 rpms. Yet the boat jumps on plane. No complaints there!

I do notice sometimes the smartcraft will be reading 5300. Then it almost feels like I apply a little brake and it drops to 5180. Now that’s an example but it’s the best way I can describe it.

Someone said a while ago. Maybe in this thread. That I shouldn’t go after a few mph with this hull. Based on the lack of separation the engine heights got me I kind of understand.
Jackplate flush: 65.5@5290
1/4 above: 65.3@5350
1/2 above: 66@5380
3/4 above: 65.9@5390

Also I’ve heard they don’t like much trim. I think I may have it trimmed about halfway at the most. And that’s running trimmed down then bumping it up slowly.

I’ll do some research on what a 24 will do for me or if it’s worth it. Fishing tournaments it’s hard to drop a boat off at a mechanic this time of year. But maybe I should. But it seems to run fine.
Can’t remember if it’s this thread or not but I did get 68 mph with the 25 trophy I had on the boat I sold. Perhaps this particular tempest I have is just a dog? Still, it should be turning 5500+.
Im just thinking if I could find those missing rpms I’d be in that 70 mph range. My water psi is about 18-20.

One question: Everyone refers to jackplate height but the engine has 5 mounting holes. Mine is mounted on the 4th lowest you can go. Or in other words, there is only one position lower. Are those mounting positions pretty standard?
Thanks.

[JayLaw]

I don't feel like your chasing MPH, your chasing an engine RPM that is not where it should be thus affecting your RPMs. If you feel like your having "brake" temporarily applied when running wide open, I would like at rebuilding the fuel pulse pump, it takes about 30 minutes to do this. Google and youtube will show you all you ned to know about doing the job. In the weather we are having now, you should be able to achieve RPMs of 5850. Have you had anyone else drive the boat yet? Preferably with Cat experience? Looking at your pic Your motor is mounted fine.

[ranger185]

If I remember, tomorrow I will check to see what hole my engine is mounted at. Same year P4 but a 200 SHO. I got the boat new with a 26 fury and had only 5100 rpm's. Switched to a 25 fury and got around 5300 rpm's. I am now running a 24 fury at 5550 with top end at 69.7. Takes a while to get there then I run out of room on the lakes I fish. Also I have a 36 volt fortrex so an extra battery and more weight in the front. It does start to walk a little when I get to about 67/68 mph.

[Judson1]

Thanks for the help fellas. We will get it figured out. I wanted to mention that I saw this yesterday. Interesting that the 2011/2012 Mercury Pro XS has an rpm range from 5500-6000. But the other year 200’s say 5-5750. Mine has 2012 on the engine sticker. I wonder why just those two years say 6000 max?
https://www.kirschbaum.at/ki_prop/pd...PM%20Chart.pdf

[Bass Cat Boats]

No 200 Opti in either Pro XS or not is a max 6000 RPM and the engines are identical other than a decal kit.

The engine height is lower and keep it down, it’s about torque and a P4 model will run with many propellers. We like smaller pitches ourselves and some run larger ones. The Pantera IV has more slippage than any other BCB model, which is where the variation comes from.

[Judson1]

No 200 Opti in either Pro XS or not is a max 6000 RPM and the engines are identical other than a decal kit.

The engine height is lower and keep it down, it’s about torque and a P4 model will run with many propellers. We like smaller pitches ourselves and some run larger ones. The Pantera IV has more slippage than any other BCB model, which is where the variation comes from.

Thanks. Im not wanting to run at 6000. But it caught my eye. Must be a typo.

[Judson1]

If I do determine a 24 would suit me better what benefit is it to run higher rpms?
Meaning I would be turning a few hundred more rpms but with a smaller pitch. Would I still expect to gain a little speed with that trade off? Hole shot is already great so speed would be the only benefit but wouldn’t the + rpms/ - pitch cancel each other out?
Not quite ready to do it. Still want to check a few items. But just asking.

[ranger185]

Judson, I got a chance to look at my engine and it is mounted on the second hole from the top. Now I have a Yamaha so there probably is a difference in the lower units. I think if you could try a 24 fury you might get to the 70 mph you want. I think the fury is a little stiffer than the tempest. May give a better bite.

[Judson1]

Judson, I got a chance to look at my engine and it is mounted on the second hole from the top. Now I have a Yamaha so there probably is a difference in the lower units. I think if you could try a 24 fury you might get to the 70 mph you want. I think the fury is a little stiffer than the tempest. May give a better bite.

Thanks. I do want to try a 24 Fury but haven’t found a loaner yet.
So today I got the boat back. Had a tune up done just to ensure there were no codes and everything was running right. Before I left the guy says he has a spare 25 Tempest I can try. It’s the same prop I’m running but I’ll try it anyways. He said it had great lift.
So can someone tell me if my line of thinking has some truth to it? MY tempest doesn’t seem to have the pointed ears that his prop did. I had forgotten that about the tempest. Or at least HIS ears had more or a point to them.
My problem is lack of rpms and speed. Could MY tempest not have the lift it needs to reduce the wetted surface? And thus hindering rpm gain because I’m plowing the water? I understand less cup would theoretically increase RPMs but if it isn’t lifting that’s got to account for something right? I guess I’ll find out in a few days.

[Grant2]

Man put a 24 Fury on that motor and be done. You can sell a Fury pretty quick if it doesn’t work, but from the looks of it you are spending time and money chasing RPM and that could be the funds for the Fury.