rslick

iTrader: (1)

Tried a (-2'') on last weekend with the same prop as I was running with the bravo 1 lower (Bravo 1 26p).

Boat seemed bow heavy and would not accept much more than 3 or 3-1/2 on the trim indicator. MPH went up by 1. Slip at mid range seemed higher than before. Top RPM increased by 100 to 5100. speed was in at 69mph on gps at 2150 feet elevation. Boat ran a little smoother through the rougher water and tracked well. H2O pressure stayed within reason at 23 to 24 lb. Planning did not suffer much at all. I do have 380 k-planes that help.

Any ideas on another prop to try or should I try a spacer?

Thanks

tblrklakemo

try a five blade?

Beak Boater

Im suprised you ran a 2 inch shorter gearcase, and ran the same prop without hitting the rev limiter. Based on your numbers you are at about 18% slip, which is pretty high. Im no prop expert. But the Mercury Maximus or Hydromotive PX5 would be a good choice. Talk to Brett at BBlades, or Julie and Matt at Throttle-up. Both of them are on the board, and may offer some advice on your set-up and proper prop selection. They can save you a lot of trial and error, not to mention $$$

chief fever

rslick, I have a 98 29ft Fever with a Imco 2"shorty,Imco Ext. Advantage Drive,i have tried every just about every prop out, the 5 blade Maximus has been the best choice.Have not had much success with Hydro P5x 5 blades have 2 of them,Pm me if you want more input i have tryed 12 props on my boat,last time out 98.5 on gps,28 Maximus labbed minus diffuser tweaked by Bblades,950+hp Chief Power!!,Don't hesitate to pm me,Ray.

bob_t

Our 2000 29' had X-dim of 17.5" and 500EFI. Best we ever saw was 73.7 mph on local lake at 200' elevation, cool (actually cold) day, low on fuel, 1 person, blah, blah, blah. Prop was thinned 24P Hydro Q-IV. 25P seemed to strain the motor and gained nothing on top end. Even with the 17.5 X-dim, it would blowout the Q-IV prop when cornering. Our current 2002 29' (and all of the newer 29's) have X-dim at 19.5, which is probably about where you were with the -2" shorty. Current boat with Merc 575 is running a 28P B-1 prop in hot weather, and 30P in cool weather, on 1.5 gear ratio XR drive. Slip seems to be high, but given the high X dimension, not suprised - you can actually see the prop wash going sideways off the blades at the cavitation plate when you look out over the back of the boat, with the drive trimmed at 4.5 . Not much of the prop in the water! It doesn't blowout when cornering, though. Tried a 28P Hydro Q-IV and could not even get on plane - as soon as the boat started to come over, it would blowout the prop and just squat in the water, with the engine bouncing off the rev limiter! Tried all kinds of ways to get the boat up on plane, short of towing it with another boat, and never got it to not blowout. Speed with the 28P B-1 on GPS is currently 75 +/- mph, 90+ degree heat, loaded with fuel, wife, kids, toys, coolers, bimini top, etc. From what I have been told that, in the heat, the 575's run about the same speeds as the new 525 EFI's. Several of the test reports I have seen for the 525 boats show 76-77 mph on GPS speedos, spinning 26P B-1's at 5300+ rpm, and X-dim at 19.5" I pick up about 1 mph spinning a RH prop, but the boat leans really hard, and I don't like that. Its a really strange feeling when you are powering up, getting on plane.

Rebel_Heart

Just curious, Chief Fever what didn't you like about the PX5s? I haven 't tried the Maximus, but had great results with the Hydros. What did the Maximus give you?

Rebel_Heart

I liked the B-1 with my -2 Imcos, but lost quite a bit in mid-range. Slip was 16%, decreased slip to 11% with a five blade and picked up on top. I, too was running the Quad 4s with standard drive height, but had a lot of slip at 16 3/4 x-dim - on turns, out of the hole, etc.