With that type of load my 31hp MB on a 17x60 boat runs 18mph at 3750rpm's, guess we need to mod to keep up
| MudmotorTalk.com http://mudmotortalk.com/mmt_v2/ |
|
| 35 MBSD http://mudmotortalk.com/mmt_v2/viewtopic.php?f=2&t=5819 |
Page 1 of 1 |
| Author: | Sawyer [ Tue Nov 03, 2009 9:01 am ] |
| Post subject: | 35 MBSD |
my gf's dad loaned me his duck boat (18x54? maybe? i know its 18 foot. it has a 35 MBSD on it. it had 46 hours when i got it. prop wasnt worn or anything. been noticing that im not getting the performance everyone else is out of there duck boats with similar set ups. only running about 3750-3780 rpms and with 2 people me weighing 210 and another weighing 230ish and a dog that weighs 70lbs only getting 20mph in deep water. everyone else i know gets atleast 23-24 or better. didnt think much of it untill i found out my rpms should be in the 4's...any input on what the problem might be? |
|
| Author: | Kirby [ Tue Nov 03, 2009 9:13 am ] |
| Post subject: | Re: 35 MBSD |
With that type of load my 31hp MB on a 17x60 boat runs 18mph at 3750rpm's, guess we need to mod to keep up
|
|
| Author: | WestEndAngler [ Tue Nov 03, 2009 9:37 am ] |
| Post subject: | Re: 35 MBSD |
I'd check your out of water RPM and see what your engines RPM peaks too... You should be turning around 4250 out of the water. |
|
| Author: | Sawyer [ Tue Nov 03, 2009 10:07 am ] |
| Post subject: | Re: 35 MBSD |
ill check that out today. if im not what could be the problem? im gonna change the oil in it today, that shouldnt have any affect on the rpm's should it? |
|
| Author: | WestEndAngler [ Tue Nov 03, 2009 10:18 am ] |
| Post subject: | Re: 35 MBSD |
| Author: | Sawyer [ Tue Nov 03, 2009 12:40 pm ] |
| Post subject: | Re: 35 MBSD |
im motor stupid...i dont know the first thing about them. in neutral i revved it all the way up and it hit 3860 rpms. |
|
| Author: | Kirby [ Tue Nov 03, 2009 12:46 pm ] |
| Post subject: | Re: 35 MBSD |
I think you check it in gear |
|
| Author: | Sawyer [ Tue Nov 03, 2009 12:48 pm ] |
| Post subject: | Re: 35 MBSD |
in gear was less i think..it was either less or around the same. i tried both ways |
|
| Author: | WestEndAngler [ Tue Nov 03, 2009 2:16 pm ] |
| Post subject: | Re: 35 MBSD |
Well in neutral I hit 4250 with my 35hp briggs engine |
|
| Author: | Sawyer [ Tue Nov 03, 2009 5:58 pm ] |
| Post subject: | Re: 35 MBSD |
i got it squared away. i was hitting in between 4150 and 4200. went and ran it with 2 ppl it hit 24.4mph in deep extremely rough water. waves looked like i was at the beach. closest boat ramp is right below a dam and they were letting water out so it was rooouuugghh |
|
| Author: | richardb [ Tue Nov 03, 2009 6:09 pm ] |
| Post subject: | Re: 35 MBSD |
so what did you do to fix it. |
|
| Author: | Sawyer [ Tue Nov 03, 2009 7:48 pm ] |
| Post subject: | Re: 35 MBSD |
a buddy of mine actually did it. i watched him do it but i cant explain it. i am an idiot when it comes to motors so idk what everything is. i know it was a screw connected to the throttle cable. it wasnt the screw under the air filter but the one behind it to the left. someone else who has a better understanding of these things maybe could explain what we did to it better? (based on what little info ive given 
|
|
| Author: | dog walker [ Tue Nov 03, 2009 10:12 pm ] |
| Post subject: | Re: 35 MBSD |
What type of hull (brand/style) is it on? That has alot to do with the performance,some hulls even though they are marketed for duck hunting are not the best for mud motors. |
|
| Author: | WestEndAngler [ Wed Nov 04, 2009 7:17 am ] |
| Post subject: | Re: 35 MBSD |
Sounds like he tightened up the governor spring he just used a phillips head and turned that screw back there where you described to the right and checked the RPM it would hit... That's all we were telling you to do... These engines are not hard to learn on so have your buddy explain what he is doing... Basically by tightening that screw / spring your governor is engaging at a higher RPM allowing you to turn more RPM's. |
|
| Author: | Sawyer [ Wed Nov 04, 2009 9:23 am ] |
| Post subject: | Re: 35 MBSD |
ahh ok i see. its a go devil 18x? im not sure how wide it is. its the open floor boat. whats the max rpms that motor can go 2? it ran at 4150 yesterday with me goin down the river..can it go higher? |
|
| Author: | WestEndAngler [ Wed Nov 04, 2009 10:27 am ] |
| Post subject: | Re: 35 MBSD |
| Author: | Sawyer [ Wed Nov 04, 2009 11:16 am ] |
| Post subject: | Re: 35 MBSD |
24.4 mph w 2 people. im taking it out again today on some calmer water. as long as that is somewhere in the norm im fine i just don't want to mess the motor up. i have had some people tell me they are turning around 4400? give or take some. that seems to be a little high? |
|
| Author: | deadbird8 [ Sun Nov 15, 2009 6:56 pm ] |
| Post subject: | Re: 35 MBSD |
On a stock motor setting the governor around 4250 Out of the Water is safe. At about 4400 RPM you can risk valve float (different on every motor). If you want to run higher RPM then you can have the valve springs shimmed to remove the valve float limitation and run up to about 4500. Here is some info on setting the governor- lets you know what the guy did: http://www.allmudmotors.com/blogs/how-t ... k-vanguard |
|
| Page 1 of 1 | All times are UTC - 6 hours |
| Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group http://www.phpbb.com/ |
|