have a 08 620 ranger with 250 suzuki and issues with mph

[vipro]

I am new to walleye central and apologize if i don't post this properly. I have tried 3 blades and 4 blades for the last year and am now running a 25" 14 5/8 rev 4 and one day i can hit rev limiter at 6000 and be doing 52mph and the next day 54-5600 rpm at 48mph with same fuel levels - i am presently 5 inches below pad and am at a loss - have full windshield usually my buddy and my 2 young kids in boat so 600 lbs with another 200 lbs of tackle probably. I have had my motor on the computer and they say it checks out. I am really frustrated and wondering about a jack plate but really hate to put another 2k at the problem when not sure that will fix anything or further more my problem? Any help would be greatly appreciated!

[Hot Runr Guy]

Vipro,
I eliminated your other p0sting under the Eric Olsen thread. This is the correct place for it.
HRG

[SLE]

25P prop sounds like it is a bit over propped, especialy with a Rev4 which everyone says turns really hard (although the Suzukis have a pretty deep gear in the gearcase). I'm kind of wondering if you have a ground issue or maybe a bad battery????. Assuming you have the 2.29 lower unit gears you seem to have a fair amount of prop slip (around 16%). I would expect more around 12-14% but I don't have much experience with the Rev4. On the other hand, inputing your lower numbers yeilds a 17% slip so it's atleast constant. I don't think a jack plate will solve the inconsitant speeds/Rpms, I do think it would help the overall performance though.

Good Luck

[Tim_Kelly]

Is it possible the hull's taking on water and it goes faster when the water's been drained after the bilge has been on, and slower when it's carrying water?

[I Fish GS]

I ran a 25p tempest on my suzuki 200 & crestliner 192 It ran 52mph at 5500 rpm. I would think your 250 would have no problem on a ranger. You might have to play with the prop vents if you have them, I had the biggest openings just drilled out plactic.

Brian

[CLDFRNT]

Call Kirk at The Boat Farm in LeMars IA, 712-546-9550. He ran a similar rig last year.
Good luck Mark N

[nicksteck]

i have the same exact rig, Frankies installed a 25p Rev4. i ran 57.64 mph this spring with a 1/2 tank of gas and my wife and i.

last year in Canada 3 guys in the boat, full live and bait well full tank of gas 52 mph