07 620 with 250 pro xs performance questions

[10lbwalleye]

Curious what others are seeing for top end speed and rpm with similiar setups. WOT, I can get 5500 rpm and 56mph gps with a 21p tempest prop, two guys and half tank of gas with a pretty good load of gear and 9.9 and 4 batteries. Does this seem in line with what performance others are getting? I have read numerous posts and blogs on how the 07 was the fastest hull in the 620 and thought i might get a little better top end. When running at max trim position before blow out my incidator on the dash is just a shade under the first 1/4 slash mark above the D. My rooster tail is only around 12" high at this position which i thought was a little low. I forgot to look what hole the motor is mounted in but can get that with a phone call if needed.

Thanks for any feedback. I dont have past experience with a boat this size to fall back on so i hate not knowing if i am getting all i can get out of it.

[PJM]

10lb

That hull in my opinion was faster then then the mid 08 hull to the present. You are in the ball park as far as speed with a heavy load assuming the live-well is full. The boat will go faster with a 23p with nothing in the boat but most people don't run that way. If you want to go faster have the prop reworked. I think you might need some prop work because I had a Yamaha four stroke on that same hull and I was one mph faster with the same load and your motor is much hotter then that Yamaha

[kroe]

I have that same year and setup. I have 5 batteries, 9.9 kicker. The fastest I have been is 62 mph fully loaded with just myself in the boat. It was in perfect conditions dialed in at about 5900 rpm give or take. The only difference is that I am using the 23 pitch Tempus three-blade prop.

Kroe

[mrbreeze]

I had that same boat with a 23P, low fuel, by myself, I could hit 63mph, I think even 65 once, at ~5900 rpm. I don't have the rig anymore and can't remember where it was mounted. But, I would think that with a 21P and the load that you mention and height, you are probably in the ballpark. You are not however hitting the rpms that I would think that you should. I can't remember the recommended is 5950 or 6000 I think. I'm a believer in getting the r's up in the recommended range if you can.

That combination should pretty much walk away from any other 620 on the water. Or pretty much any other similar boat.

[10lbwalleye]

I guess thats my biggest concern, why i cant get above 5500rpm. I will be checking motor height this weekend. Is it not possible to get those rpms with a 21?

[Skeeter20]

My buddy has the same boat with a 225 etec and jackplate. He runs 58 loaded up with 2 guys, his best I think is 60-61. He is running a raker 22p 5800-6000rpms.

[mrbreeze]

I don't know...propping is not at all my area of expertise. You might want to give Merc a call...they have actually done some pretty extensive testing with the pro xs on that exact hull. They have been extremely helpful when I have called them in the past. In fact, there may be some spec sheets on their website for the '06-'07 620 hull.

[TJEli]

I think you have one of 3 issues..

Your motor may be down on power... bad coil pack?

Your prop could have a problem..

Your motor could be mounted WAY too low..


I am leaning towards a coil pack. Have it checked out. That boat and motor with a 21P Tempest should easily be pulling close to 6K RPM with that load.

-Eli

[mrbreeze]

Worth checking the coil pack (and if you can get them to change them under warranty bonus), but when I lost a coil, it wouldn't even get up on plane.

[Buzz]

Originally Posted by mrbreeze

Worth checking the coil pack (and if you can get them to change them under warranty bonus), but when I lost a coil, it wouldn't even get up on plane.

I just replaced the coil pack on my 225 Optimax (non XS) under warranty. Same problem, could hardly get onto plane.