| MudmotorTalk.com https://www.mudmotortalk.com/mmt_v2/ |
|
| Bottom of Boat to Shaft Distance https://www.mudmotortalk.com/mmt_v2/viewtopic.php?f=2&t=75345 |
Page 1 of 1 |
| Author: | countryduck [ Mon Oct 12, 2020 7:31 pm ] |
| Post subject: | Bottom of Boat to Shaft Distance |
Have had a Mud Buddy Mini 23 on my old 1648 for a few years now and it has never seemed to run good. It just plows with anything more that me and a little gear and even then it’s running under 16 mph. I can’t ever get the rpm in water above 3400ish. I was looking at pictures and threads here and got to noticing how high it seems my lower unit sits relative to the bottom of the boat. I ordered a tall transom model and the transom measures 22” along the angle and 21” if measured vertical. Transom angle is 15 degrees. But the distance from the center line of the prop shaft to the bottom of the boat is 9.5” if the shaft is parallel to the hull bottom. The bottom of the skeg is 3.5” above the bottom of the boat. This seems way to high, but I am not sure. Can anyone tell me if this may be part of my issue? Also I am at 4000 ish ft of elevation so I’m sure that’s a factor. |
|
| Author: | Russ [ Mon Oct 12, 2020 8:10 pm ] |
| Post subject: | Re: Bottom of Boat to Shaft Distance |
Definitely a condition of short transom motor on tall transom boat. May not be the only issue, but it's for sure a big one. #CFFITR #mudmotor>physics |
|
| Author: | Gigafowl [ Mon Oct 12, 2020 10:09 pm ] |
| Post subject: | Re: Bottom of Boat to Shaft Distance |
Yep - you don't want that lower housing in front of the shaft below the hull but you need to be able to trim most if not all of the prop down below the hull to dig in mud then trim up to where the shaft is at the bottom of the hull for best speeds on plane... Several fixes - modify transom / replace SD or modify SD to tall transom / jack plate When setup right - that spray shield above the prop should align with the bottom of the hull for full on mud digging - then as you trim up you find the "sweet spot" for the given load and conditions to get best speeds... I bet when your spray shield is parallel with the bottom of the boat your SD is 4" or more too high... Even LTs have the same problems when mismatched from tall to short transom hulls... A good fab shop could cut down the transom - that seems to be what most guys choose and keep the piece they cut out in case you ever want to go back to tall transom Or go big - get a bigger SD with tall transom specs - but then you will want an 18' hull - etc... Happy Hunting ! |
|
| Author: | Mallards Only [ Tue Oct 13, 2020 6:48 am ] |
| Post subject: | Re: Bottom of Boat to Shaft Distance |
Definitely not set up right. Did you mount it yourself or have a shop do it? Just based off the pics, that looks like a short shaft motor on a tall transom. Did you measure your shaft length of the motor to see if they sent you the right motor? If they did, then it's mounted too high. I can't really tell from the pics if it can be lowered enough to be properly set up. As far as the elevation, I'm not familiar with the MB 23's. Do they have EFI? If not, then you may need to change your jets for the elevation. |
|
| Author: | countryduck [ Tue Oct 13, 2020 8:30 pm ] |
| Post subject: | Re: Bottom of Boat to Shaft Distance |
I ordered the motor straight from mud buddy and installed myself. I looked up my email receipt and it says tall transom like I ordered but I’m thinking they sent me a short transom. I need to measure it to confirm. Not sure they would do anything though as I bought it three years ago now. I can tig and have a spoolgun so I could modify if I need to, but is the handle going to sit too low while running it? |
|
| Author: | Mallards Only [ Wed Oct 14, 2020 8:18 am ] |
| Post subject: | Re: Bottom of Boat to Shaft Distance |
Don't those motors have a floating handle? |
|
| Author: | Bigbend [ Wed Oct 14, 2020 6:24 pm ] |
| Post subject: | Re: Bottom of Boat to Shaft Distance |
I cut mine down. If that handle isn’t adjustable it may be easier to fab a handle. Or call mud buddy and see if they can work with you on a new out drive. 13BDEE1D-A868-4690-9DD9-99C95BFB22AC.jpeg 119D5AD8-3026-4B63-8655-81E8D7D703C3.jpeg |
|
| Author: | countryduck [ Wed Oct 14, 2020 6:33 pm ] |
| Post subject: | Re: Bottom of Boat to Shaft Distance |
Mallards, you are right it is. Forgot about that. Thanks for the help. Bigbend, I actually searched on here and found your pictures. I think if I can’t get mud buddy to do anything I’ll go ahead and copy you. Thanks Thanks to everyone else that responded too! |
|
| Author: | bluesky2012 [ Wed Oct 14, 2020 7:13 pm ] |
| Post subject: | Re: Bottom of Boat to Shaft Distance |
Has anyone else noticed that we’ve had a few different times where this same thing happened from mud buddy? Sent from my iPhone using Tapatalk |
|
| Author: | countryduck [ Thu Oct 15, 2020 11:39 am ] |
| Post subject: | Re: Bottom of Boat to Shaft Distance |
Took a few more pictures last night. Based on what Giga said it’s not too far off. |
|
| Author: | Bigbend [ Thu Oct 15, 2020 12:00 pm ] |
| Post subject: | Re: Bottom of Boat to Shaft Distance |
^ That looks pretty far off in my opinion. Look at the angle your engine is at to achieve the prop height. When mine is in the water and not running, the spray shield/cavitation plate is just under the surface of the water and the engine is almost perfectly level. Once I'm running and get to full RPMs my prop is half in the water/half out - I have a GDSD though. People on here spend thousands on a couple of MPH gains, even when their motors are matched correctly. I have an old 1648MV, matched with a 23hp GDSD and with me and a light load I average 21 mph. Two people and hunting load I'm around 16-17 mph, but still on plane. I'm think you should be at least close to that. What sucks is that it sounds like MB made a mistake and sent you a short transom motor, and you didn't catch it right away and now its going to be more difficult to get MB to cooperate. |
|
| Author: | countryduck [ Thu Oct 15, 2020 6:23 pm ] |
| Post subject: | Re: Bottom of Boat to Shaft Distance |
Confirmed today it is a tall transom motor. So might try bringing the transom down to the lower end of the recommended specs. |
|
| Author: | Russ [ Thu Oct 15, 2020 8:22 pm ] |
| Post subject: | Re: Bottom of Boat to Shaft Distance |
Screw recommended specs. Based on your measurements, I would drop the transom 5 inches. The bottom of the belt housing should be just above the bottom of the boat. I think mine was 2 inches or something close to that. Not the skeg. A tall transom frame is for a 21" transom, give or take depending on manufacturer. For it to be off that much, something isn't right with that "tall transom" frame you have. You confirmed how? They told you the serial number is for a tall transom? Or did they give you measurements and you compared to the same measurements on your frame? #CFFITR #mudmotor>physics |
|
| Author: | Bigbend [ Fri Oct 16, 2020 5:42 am ] |
| Post subject: | Re: Bottom of Boat to Shaft Distance |
| Author: | countryduck [ Fri Oct 16, 2020 10:19 pm ] |
| Post subject: | Re: Bottom of Boat to Shaft Distance |
I called and got the measurements of the belt housing from mud buddy and confirmed them on mine. I agree it doesn’t seem right. I’m fine with cutting the boat up so I’ll give it hell and lower it down. To around the height you guys are saying. |
|
| Page 1 of 1 | All times are UTC - 6 hours |
| Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group http://www.phpbb.com/ |
|