Author |
Message |
jthib24
MMT Pro Member
Joined: Sat Aug 20, 2011 1:28 pm Posts: 93 Location: Orange, TX
|
 27hp gdsd too slow?
Running at 27 gdsd on a 15X50 allweld. I know it has the crimped bottom, but with just myself (210lbs), a battery, and 6 gallons of gas I can MAYBE touch 21mph...surely I should be running mid 20's correct? I'm wondering if it could be prop wear? The motor is an 09 with 120 hours. Any suggestions/thoughts?
_________________ 27 gdsd pushing a 16X48 gd boat
|
Sun Oct 09, 2011 10:44 pm |
|
 |
Gigafowl
MMT Elite Member
Joined: Tue Jan 13, 2009 7:19 pm Posts: 6441 Location: Trinity Bay - Texas
|
 Re: 27hp gdsd too slow?
Well - starting with the prop wear - 2 or 3 blade and when you measure across the widest part of the blade - how wide is the blade ???
(not diameter - but blade width)
_________________ Eat - Sleep - Hunt ! ! !
"It is good to have an end to journey toward; but it is the journey that matters, in the end."
|
Sun Oct 09, 2011 10:53 pm |
|
 |
jthib24
MMT Pro Member
Joined: Sat Aug 20, 2011 1:28 pm Posts: 93 Location: Orange, TX
|
 Re: 27hp gdsd too slow?
3 blade...and it looks like the widest part on one of the blades is 3.5"
_________________ 27 gdsd pushing a 16X48 gd boat
|
Sun Oct 09, 2011 11:16 pm |
|
 |
Gigafowl
MMT Elite Member
Joined: Tue Jan 13, 2009 7:19 pm Posts: 6441 Location: Trinity Bay - Texas
|
 Re: 27hp gdsd too slow?
Prop is like new then.... Any tach for checking RPMs....
Have you tried moving weight around - gas tank to front of boat ??? Tried turning the trim knob till about half of prop is surfacing and RPMs come up a bit ???
_________________ Eat - Sleep - Hunt ! ! !
"It is good to have an end to journey toward; but it is the journey that matters, in the end."
|
Sun Oct 09, 2011 11:30 pm |
|
 |
jthib24
MMT Pro Member
Joined: Sat Aug 20, 2011 1:28 pm Posts: 93 Location: Orange, TX
|
 Re: 27hp gdsd too slow?
Running about 3600-3800 rpm at WOT. Tried putting a buddy on the bow, adjusted trim almost every way possible. Still runs about the same.
_________________ 27 gdsd pushing a 16X48 gd boat
|
Sun Oct 09, 2011 11:46 pm |
|
 |
Gigafowl
MMT Elite Member
Joined: Tue Jan 13, 2009 7:19 pm Posts: 6441 Location: Trinity Bay - Texas
|
 Re: 27hp gdsd too slow?
Sounds like too much trim or some kind of drag issue with the hull....
When I turn that prop at 3800 rpm - my speed is 28 mph in a GD hull....
_________________ Eat - Sleep - Hunt ! ! !
"It is good to have an end to journey toward; but it is the journey that matters, in the end."
|
Mon Oct 10, 2011 6:34 am |
|
 |
jthib24
MMT Pro Member
Joined: Sat Aug 20, 2011 1:28 pm Posts: 93 Location: Orange, TX
|
 Re: 27hp gdsd too slow?
Yeah, thats about what i figured i'd be running in a 15x50...im all out of guesses. Im gonna take it to a local guy here who builds custom boats and see if he has some input.
_________________ 27 gdsd pushing a 16X48 gd boat
|
Mon Oct 10, 2011 10:15 am |
|
 |
Woodiebuster
MMT Elite Member
Joined: Wed Mar 03, 2010 7:00 pm Posts: 6060 Location: Choudrant, La
|
 Re: 27hp gdsd too slow?
_________________ CSM Custom 18x42 Battleship with a 36 PD beating you to the hole My Rig (Old Motor) viewtopic.php?f=5&t=45193
(New Motor) viewtopic.php?f=5&t=54733 Stumps Fear Me
|
Tue Oct 11, 2011 4:45 pm |
|
 |
Gigafowl
MMT Elite Member
Joined: Tue Jan 13, 2009 7:19 pm Posts: 6441 Location: Trinity Bay - Texas
|
 Re: 27hp gdsd too slow?
The gear ratios are different - but only slightly - no more than 1 to 2mph difference at similar rpms...
_________________ Eat - Sleep - Hunt ! ! !
"It is good to have an end to journey toward; but it is the journey that matters, in the end."
|
Tue Oct 11, 2011 6:31 pm |
|
 |
jthib24
MMT Pro Member
Joined: Sat Aug 20, 2011 1:28 pm Posts: 93 Location: Orange, TX
|
 Re: 27hp gdsd too slow?
anything think some float boxes would help my boat run a little faster? im thinking by getting the ass end out of the water a bit, i may pick up a few mph...thoughts?
_________________ 27 gdsd pushing a 16X48 gd boat
|
Thu Oct 13, 2011 11:26 pm |
|
 |
Gigafowl
MMT Elite Member
Joined: Tue Jan 13, 2009 7:19 pm Posts: 6441 Location: Trinity Bay - Texas
|
 Re: 27hp gdsd too slow?
I would guess - no...
Pods just help from a dead stop to decrease draft which is why they are great in helping an outboard get up in shallow water - they add drag at planing speed - IMO you would get more gains by relocating fuel and battery to the front of the hull...
_________________ Eat - Sleep - Hunt ! ! !
"It is good to have an end to journey toward; but it is the journey that matters, in the end."
|
Thu Oct 13, 2011 11:36 pm |
|
 |
jthib24
MMT Pro Member
Joined: Sat Aug 20, 2011 1:28 pm Posts: 93 Location: Orange, TX
|
 Re: 27hp gdsd too slow?
roger that...gas tank is already up there...only thing left to try is the battery. Trying to avoid buying a new boat.
_________________ 27 gdsd pushing a 16X48 gd boat
|
Thu Oct 13, 2011 11:38 pm |
|
 |
gariverrat
New Member
Joined: Sun Jun 05, 2011 8:18 pm Posts: 2 Location: Valdosta, Ga
|
 Re: 27hp gdsd too slow?
Also need to make sure that you have the correct mud motor on the boat relative to transom height. Transom height effects your trim/speed. My Express 15x48 has a ribbed bottom and 23 vanguard. WOT with one person, fuel full and some gear is 26 mph. Good luck.
_________________ 1548 Express, 23 Gd Surface drive
|
Mon Oct 24, 2011 8:13 pm |
|
 |
jthib24
MMT Pro Member
Joined: Sat Aug 20, 2011 1:28 pm Posts: 93 Location: Orange, TX
|
 Re: 27hp gdsd too slow?
Just got the motor back from the shop. Had new belt put on and a tune up done. Took it out today...with me (210), my buddy (180), and my lab (90), ran 23-24 and hit 26 in the shallows! Not bad I'd say.
_________________ 27 gdsd pushing a 16X48 gd boat
|
Wed Nov 02, 2011 12:25 am |
|
 |
Gigafowl
MMT Elite Member
Joined: Tue Jan 13, 2009 7:19 pm Posts: 6441 Location: Trinity Bay - Texas
|
 Re: 27hp gdsd too slow?
All right - thats about as good as you could ask for speed wise with that load
You ought to be ready to go for opener now
Good Luck
_________________ Eat - Sleep - Hunt ! ! !
"It is good to have an end to journey toward; but it is the journey that matters, in the end."
|
Wed Nov 02, 2011 6:57 am |
|
 |
|