new lower unit now its faster???

[6 balls]

I just got my boat back on Saturday afternoon after i tore the lower unit up. Everything that was replace is oem the boat is a 05 bayliner 185 with the 3.0ltr. Before the damage the fastest the boat ever ran with just my wife and i in it and full fuel was 42 with the currant. Sunday we ran 47 mph against the currant same water conditions and same fuel. How can that be????? also i dont rember the rpms i was running at wide open throttle but now it runs 5000 maxed out is that ok for the motor???? or that spinning too fast?

 

[4poco]

Re: new lower unit now its faster???

Also have 05 bayliner,only diff. is mine is a 175<br />personally I wouldnt even consider 5000 rpms/4400 max. But its your ride (19 pitch

 

[fullsize_chevy]

Re: new lower unit now its faster???

If you're talking a 3.0ltr mercruiser, then you're spinning too fast. Max RPM @ WOT should be between 4400 - 4800 RPM (per documentation). It sounds like you're under-proped a little. Replace your prop with a prop 2" more pitch and you're RPM's will probably fall right within that range. Even better...you're top end probably won't change too much and you won't be damaging your engine! Good Luck.

 

[6 balls]

Re: new lower unit now its faster???

thanks for the info i only had it at that rpm for about 30-40 sec not something i run all the time i doubt if i did any damage but i felt that the rpms were a tad bit high so i backed it down to 4500

 

[craze1cars]

Re: new lower unit now its faster???

Are you sure you got your prop back? Almost sounds to me like the dealer may have put somebody else's prop on. Or since you likely tore up the old one when you tore up the drive, they didn't replace it with the same pitch.<br /><br />If that prop is brand new and has no damage, I'd take it back to the dealer immediately and see if they'll exchange it for one with a 2 inch larger pitch. That'll bring you right into range.

 

[6 balls]

Re: new lower unit now its faster???

part number on the new prob ends with a P21 so i would guess that means pitch 21 that is the same as the one that came on the boat i will call tomorrow to make sure it that is the right part guess i just need to watch the tach

 

[TwoBallScrewBall]

Re: new lower unit now its faster???

I agree sounds like you got a different prop.

 

[umblecumbuz]

Re: new lower unit now its faster???

Craze1cars:If that prop is brand new and has no damage, I'd take it back to the dealer immediately

Sounds like great advice. Even if it's the same pitch prop, telling the dealer that it's over-revving your motor might persuade him to change it for one of a higher pitch.

 

[craze1cars]

Re: new lower unit now its faster???

Of course, now that you're telling us it's a 21P, I'm second guessing. A 21P on a 3.0??? And it's already over-revving? I'm surprised that a 3.0 could push a 21P on a boat that size, and even more surprising would be that you'd need to go to a 23P to bring it within range.<br /><br />That's pretty much unheard of. Most 3.0 boats in my experience are running 17P or 19P props at the most.<br /><br />Makes me wonder if something is actually slipping, or the prop is maybe ventilating. Or the tach may be calibrated wrong. Just getting 47 mph outta this rig sounds a bit surprising in itself.<br /><br />I'd ask the shop about this, something just doesn't seem quite right here based on the facts provided.

 

[danie]

Re: new lower unit now its faster???

Overall it sounds as if you have a good setup.<br />It doesnt sound like you need holeshot so bring the revs down and enjoy the good top speed.

 

[ron7000]

Re: new lower unit now its faster???

the outdrive is a powertrain loss like any vehicle. The new drive is brand new and has less drag in the water, and the old one may have been robbing some power. Usually a new gearcase will be tight and rob more power till it wears in, but if you're getting more out of it than before good for you.<br /><br />I wouldn't buy a higher pitch prop unless you want to play. In the near future you'll be back to normal speed, the drive case will get dirty or if the engine is the slightest bit out of tune. If anything a 23" prop will hurt the holeshot if you need one like pulling a skier.<br /><br />I have a 2002 bayliner 1905 capri with cuddy and the 3.0L. OEM prop is 14x21 and will turn 4800-4900. Have a 13.75x20 4-blade stainless on right now and it still hits 4800 easy but I've also messed with the carb and the motor and hull is 100%. I get somewhere around 45mph on handheld gps if I remember right.

 

[6 balls]

Re: new lower unit now its faster???

thanks for the input i called the boat shop today and they are stating that the rps are normal. I ran it today and it was not hitting 5000 it was 4800-4900 didnt hit over 4900. The boat shop says that the speed is more then they would have guessed and think my wife and i need to eat more the two of us combined are only 240 lol. They say the motor has a rev limiter and shuts off at 5100 and that the rpms i was turing are not bad unless prolonged, and i rarely run over 4000

 

[inthesticksnow]

Re: new lower unit now its faster???

21p, is standard and proper for this boat. Over 45 MPH WOT is easy for this boat at 4800 RPM.

 

[CF 5491 PF]

Re: new lower unit now its faster???

I usually run higher horsepower Mercruisers that have rev limiters that kick in about 200 rpm above WOT, does the 3.0L have a rev limiter? My friend has a '96 Crownline 18BR w/ a 4.3L, he has to limit his throttle range, no limiter.

 

[Sooner44]

Re: new lower unit now its faster???

I have two 3.0L both with 21 pitch. 21 pitch comes standard on all Glastron 175 3.0L/<br />And my book read 4400 - 4800 rpm for the 3.0<br />I run 4400 @ 42 MPH WOT with both my SR and GT.

 

[QC]

Re: new lower unit now its faster???

How are you measuring your speed? Merc speedos are through the drive . . . Could be slightly different. On the other hand, GPS numbers are meaningless in current as far as speed in the water is concerned. So this is a little bit of an issue, the Merc speedos are notoriously inaccurate (mine is dead on, go figure) and GPS is wrong when in current (speed over the bottom is dead on).

 

[inthesticksnow]

Re: new lower unit now its faster???

Originally posted by 6 balls:<br /> I just got my boat back on Saturday afternoon after i tore the lower unit up. Everything that was replace is oem the boat is a 05 bayliner 185 with the 3.0ltr. Before the damage the fastest the boat ever ran with just my wife and i in it and full fuel was 42 with the currant. Sunday we ran 47 mph against the currant same water conditions and same fuel. How can that be????? also i dont rember the rpms i was running at wide open throttle but now it runs 5000 maxed out is that ok for the motor???? or that spinning too fast?

The only other thing I can think of (unlikely but I suppose possible) is that for some reason you got your new ’05 185 delivered with the wrong prop to begin with, like a 23p… then you tore up the drive, and it was replaced but with the correct 21p prop. That would account for the 42 MPH before, and the 47 MPH now. But you should not be running at 5000 RPMs with a 21p prop. I have seen 48, and even 49 MPH on my speedometer with just the wife and I onboard, but never more that 4800 RPM. <br /><br />I have the exact same boat and year. The 21p on ours produces exactly 4800 RPM at WOT, based on MY tach (same as yours). If your tachometer is functioning correctly (likely), you may be trimmed out a tad too much? Over here, I do not trim all the way up to the ¼ mark on the trim gage, but just a tad below because the prop can spin-out sometimes (cavitate). That 3.0 is going to spin at 4800 RPM with a 21p prop properly trimmed, on a 2005 Bayliner 185, at WOT no matter weight, currant, or fuel load. If you are loaded with people and extra weight, that work horse 3.0 of yours will still reach 4800 RPMs… but will run slower MPH.<br /><br />I am not an expert, but I do have the same boat and drive train, and can report the above experience. If you’d like, I can put you in touch with at least two other 185 owners. Just PM me for the link.

 

[g0snj]

Re: new lower unit now its faster???

the speed difference you talk of is the difference between running with the current and against the current, if your using the boat speedo that is.

 

[g0snj]

Re: new lower unit now its faster???

sorry that should have read if your usung gps to check ya speed

 

[6 balls]

Re: new lower unit now its faster???

inthesticksnow i would like to send you a PM but i cant find the link to send you one