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 16' Xpress/Mud Buddy speeds 
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Post 16' Xpress/Mud Buddy speeds
Just picked up a 16' Xpress with a 31hp Mud Buddy Hyperdrive. Took it out for a run this morning and with two guys, guns, and a dozen decoys we were running an average of 14mph in deep water. I guess my question is if this is what I should be expecting to see for a top speed? I kind of anticipated that it would run a little quicker.


Sat Oct 28, 2017 6:39 am
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Post Re: 16' Xpress/Mud Buddy speeds
Lot of variables left out. What size boat, flat bottom or v bottom, where are the batteries located, where did you have the majority of the weight, what kind of shape is the prop in, is the bottom of the boat rough, how many rpms were you turning? Answer these and it will help narrow down the answer.


Sat Oct 28, 2017 7:06 am
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Post Re: 16' Xpress/Mud Buddy speeds
It's a 1652 mod V flat bottom, batteries located in back, tried to keep weight fairly evenly distributed, unsure of prop size but I can check in a bit, I know it's a little bigger than the stock prop, bottom of the boat is ribbed but otherwise smooth, and I'll pay attention to the tach on the ride out


Sat Oct 28, 2017 7:34 am
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Post Re: 16' Xpress/Mud Buddy speeds
If the prop is incorrect diameter and bigger than what is recommended you will lose rpms and be under powered.


Sat Oct 28, 2017 8:03 am
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Post Re: 16' Xpress/Mud Buddy speeds
Just got off the water, don't have a tape on me but I can check when I get home, what is recommended prop size?
It was having some serious issues on the ride home. It would lug and bog and run around 2500 for a while, and then I pulled the filter cover off and it ran a bit better, previous owner said he re-jetted it, I'm thinking he might've went a little rich. Otherwise I was seeing 37-3800 rpm when we were in the shallows and it was running good, deep water when it seemed to be running the best it was turning about 3300. Max speed on the way home was around 12, I dropped my buddy off at the landing and hit 23 by myself, this is my first surface drive but that doesn't seem right to me.


Sat Oct 28, 2017 10:02 am
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Post Re: 16' Xpress/Mud Buddy speeds
Add to the list above and it could just be a bit low on power. 31hp stock,,, maybe an oldie= 27hp,,


Sat Oct 28, 2017 9:17 pm
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Post Re: 16' Xpress/Mud Buddy speeds
It still shouldn't have as much trouble as it does with two guys though should it? My buddies 25hp long tail pushed the same size boat noticeably quicker with the same load.


Sun Oct 29, 2017 3:52 am
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Post Re: 16' Xpress/Mud Buddy speeds
You probably need a valve job done.


Sun Oct 29, 2017 6:01 am
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Post Re: 16' Xpress/Mud Buddy speeds
What makes you say that?


Sun Oct 29, 2017 9:01 am
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Post Re: 16' Xpress/Mud Buddy speeds
Do a compression test. If you don't know what that is, time to start searching this forum and YouTube because you haven't learned enough to be asking about specific issues on here. There is so much good information here that'll help you troubleshoot your issue. If that's too much for you, contact a good service center and let them work on it. Texas Mud Motors or Bayou Surface Drives.

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Sun Oct 29, 2017 9:12 am
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Post Re: 16' Xpress/Mud Buddy speeds
I'm capable of doing a compression test, the only reason I'm asking so many questions is because this is my first surface drive setup.
To answer a question from further up the thread, the prop on it now is a 12.25x10, and the factory prop is an 11x10


Sun Oct 29, 2017 10:04 am
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Post Re: 16' Xpress/Mud Buddy speeds
If you search the forum, you'll understand why he suggested a valve job, as well as the importance of rpms and prop size in troubleshooting problems. I get asking questions, but rpms, prop size, boat size and hull shape, compression numbers, and a clean carb are all thing that can tell you what's wrong. You'll also find some comparisons of similar hp mb surface drives and their performance, to include mine.

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Sun Oct 29, 2017 1:16 pm
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Post Re: 16' Xpress/Mud Buddy speeds


Sun Oct 29, 2017 3:00 pm
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Post Re: 16' Xpress/Mud Buddy speeds
I realize that, I knew beforehand that it wasn't an ideal setup, and that the Xpress is not the best hull for running in mud and shallows. But it was the best I could find up here within my budget, believe me I would've loved to spend the money on an 18 foot mud hull with a newer gtr, but it wasn't in the cards. I'm just trying to make the best of what I have, within a few seasons I'll be upgrading.


Sun Oct 29, 2017 6:43 pm
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Post Re: 16' Xpress/Mud Buddy speeds
Now with that being said, I'm willing to spend some money, within reason, to try and help this setup run better. The biggest issue I'm seeing is that it's lacking torque, and that it's struggling to get on plane with two guys. I can feel that it's on the verge of bringing the bow down and planing out but it seems like it's cavitating, or at least that's what it feels like, right as it's about to get up and go. I'm assuming the torque issue can be resolved with some motor work, and I'll look into that on my own.


Sun Oct 29, 2017 6:50 pm
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Post Re: 16' Xpress/Mud Buddy speeds
If it's running right, that hp can plane a 2 man hunt load with that boat. It's not running right. Without compression, a clean carb, no air leaks, and the right prop (which may be the bb), it'll never run as good as it can. Gearing can help it run better too. Mods shouldn't be the first thing you do, as that'll cover up some of whatever is going on, and you'll be chasing the gremlins.

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Sun Oct 29, 2017 7:50 pm
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Post Re: 16' Xpress/Mud Buddy speeds


Sun Oct 29, 2017 8:33 pm
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Post Re: 16' Xpress/Mud Buddy speeds
I'll do a compression test one night this week after work. If I find that it has an issue, which I'm led to believe I will, what kind of mechanic should I be looking for to work on it? I don't think there are any mud motor-specific shops in Wisconsin, would a small engine guy be capable of doing the job?


Sun Oct 29, 2017 8:51 pm
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Post Re: 16' Xpress/Mud Buddy speeds
Local machine shop or small engine shop can typically do a valve job fairly quick, and cheaply (my local machine shop does it for $8 per valve). They should also be able to deck the heads (I wouldnt go more than .020" unless you're gonna start playing with carbs and a cam, but other people will disagree. Personal preference here, but it'll be enough to have a noticeable increase in power). Unless they mod these things normally, I wouldn't let them do any port work, as they might take too much from one spot, or not enough from another. You pay for experience here. After that work, you will probably turn that big blade fine, but definitely turn that 11x10 better. Your other option is to pull the heads, ship them to someone that knows what they're doing, and let them do their thing. The heads will fit in a large flat rate usps, so it'll only cost you $15 or so to ship them.

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Mon Oct 30, 2017 7:52 am
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Post Re: 16' Xpress/Mud Buddy speeds
On an otherwise stock motor would I see gains worth paying for if I sent the heads out to be worked?


Mon Oct 30, 2017 8:10 am
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Post Re: 16' Xpress/Mud Buddy speeds
yep. but that's gotta be weighed against the available money you have to spend and the need for power. you aren't gonna gain stupid power, but my dad's boat went from struggling to plane with 3 with some gear to 4 with a light load just from heads decked 20.

I'll add there some other variables at play with his setup compared to yours, and the valve job by itself will probably make a big difference (depends on how bad they're leaking), but the porting and decking will help. They'll help more with exhaust and a different carb setup, but they'll help alone.

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Mon Oct 30, 2017 8:34 am
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Post Re: 16' Xpress/Mud Buddy speeds
Who would you recommend if I end up sending the heads out to be done? And what kind of price and turnaround time should I expect?


Mon Oct 30, 2017 2:26 pm
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Post Re: 16' Xpress/Mud Buddy speeds
Will C is Texas Mud Motors (near or in Tyler, TX)
Maxxis85 is Bayou Surface Drives (near Opelousas, LA)

I recommend either one. They're both decent dudes, and I would let either work on my stuff (and both have helped me over the phone more than a few times).

Cost and turnaround, that's their lane, I'll let them answer those questions since I don't know what they've got going on with it being so close to duck season down here.

They'll both send you a pm with their numbers after I send them a text in the morning or when they see this post.

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Mon Oct 30, 2017 9:23 pm
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Post Re: 16' Xpress/Mud Buddy speeds
Thanks man I appreciate that. That's why I was wondering about turnaround time as well, it's the middle of the season up here so I'm looking for as little time out of commission as possible


Tue Oct 31, 2017 4:50 am
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Post Re: 16' Xpress/Mud Buddy speeds
Pm sent and thank you Russ!


Tue Oct 31, 2017 7:56 am
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Post Re: 16' Xpress/Mud Buddy speeds
Got the heads back today, gaskets come in tmrw so I'll put it together tomorrow night. While I've got it partially apart are there any other little things I can do to give it a boost? And what are the specs for valve adjustment?


Wed Nov 01, 2017 5:34 pm
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Post Re: 16' Xpress/Mud Buddy speeds
Bringing this thread back up for another question. Got the heads done and back on, ran great for a little while. Now it seems like it's running very rich, spitting and sputtering and coughing black smoke. I've also noticed that there's gas coming out of the little brass fitting attached to the carb bowl that points straight up. If I completely gut the intake and leave the cover off it runs alright, but I'd like to figure out how to get it running leaner, or smoother at least. Still seems to be lacking some torque and running a tad low on rpms unless it's just me in an empty boat.


Sat Nov 11, 2017 7:49 pm
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Post Re: 16' Xpress/Mud Buddy speeds
The brass fitting that angles up must have a cap on it to run right. You may also have a dirty or leaking needle/seat combo. Just curious what work was done to your heads?


Sat Nov 11, 2017 8:25 pm
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Post Re: 16' Xpress/Mud Buddy speeds
It's got a cap on it but it has a small hole in it. Heads were decked .020" and had a valve job done.


Sat Nov 11, 2017 9:12 pm
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Post Re: 16' Xpress/Mud Buddy speeds
Seal the hole and try it


Sat Nov 11, 2017 9:38 pm
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